I forgot about the anecdote! So here it is: I was helping a friend get quotes for a furnace and AC replacement. The sales rep claimed that a two-stage furnace "would cut your heating bills in half because unless it's really cold, it only needs to run at half-power!" which is _flat out wrong_ and incredibly misleading. The furnace would have to run twice as long to produce the same heat! You cannot imagine how livid I was at this rep - I nearly kicked him out of the house. You may imagine that this incident is a big part of why I get cranky about HVAC companies. At best, this sales rep was woefully misinformed, and at worst - he was lying to try and upsell my friend. I made it clear to this sleazeball in no uncertain terms that what he just said was incorrect and he had better not be using that line on any other person ever. Needless to say, that company did not get the bid. But the company who did? They're the ones who put in a three-tonner when that house needed, at most, a 1-ton. I had set up a little 5k BTU/hr window unit for that friend and it was holding its own when it was over 90° out. Now the new system cannot dehumidify effectively and a separate dehumidifier is needed to keep the home comfortable. I'm cranky for a reason, is all I'm saying.
Wouldn't running the furnace for twice as long (at half max output) use twice as much electricity to run the blower fan? Even though you're using the same amount of gas and getting the same amount of heat? It's not much, but that's still efficiency lost.
This type of sales tactic was one of the reasons why I got out of residential HVAC and went to the commercial side. I like helping people and doing right by them.
You can explain it like water you have a valve turn on halfway it runs twice as long or a valve that's turned on all the way runs for a short period time both fill up the same amount of water just different times elapses
Tech temp on space heaters when the season's over blow them out and then stick them in trash bags when you store them this keeps them nice and clean and efficient for next season and doesn't smell like dust burning off when you first turn them on
Watching Alec patiently explaining the bleeding obvious to people he really shouldn't be wasting his time with, is like watching Road Runner. You know he's going over the cliff, but you watch and laugh anyway.
A lot of people have zero concept of how much energy different kinds of things actually use. They'll worry about leaving a light on somewhere, but leave the oven preheating until "Wheel of Fortune" is over and not give it a second thought.
And then of course, if it's winter time and your home is reasonably well insulated, that extra preheating time doesn't really matter. That heat will just disperse into the rest of the home anyway.
@@OrigamiMarie Spend about 8 seconds looking up the efficiency ratings for gas oven heating a room vs a gas furnace and heat pump vs resistive and get back to us.
Just wanted to say my thermodynamics professor loves your original video on heat pumps and shares it with every thermo class he gives. So the message is spreading
The vast majority of people have no idea how the things they rely on, on a daily basis, boggles the mind. How many people need a car to get to work, shop, etc? In the US, most people. How many people know how something simple, like how the brakes work? Yeah, a very small percentage of those same people who rely on that car to live. This makes me scratch my head. This thing is extremely important in your life, and yet you know nothing about it but "put gas in, turn key to start, dur dur dur."
@@jeromethiel4323 I also share the need to understand stuff. I think it might be common to people with ADD (I'm not 100% sure if I have ADD but I think I might, I've just finished testing and will get my results in a couple weeks).
It can be far easier to convince people to switch to electric with a demonstration. My grandmother was absolutely convinced of the superiority of her gas range. Then she saw me use my stove top as extra counter space, then a cutting board, then cook, then clean it all in 30 seconds with a squirt of 409 and 2 damp paper towls.
Absolutely love my induction stove for all those reasons (I have a very small kitchen). The only thing better about gas burners is that I can use a wider variety of cookware - but sorry, that will never offset the rest of the advantages induction brings! It's definitely harder to demonstrate heat pumps, but some before and after data might help convince a few more.
@@bgracey7225 You can get almost all of the advantages without induction. Mine is resistive and can be used with any cookware. The downside is that the glass cook top gets hot and stays hot for a long time after you're finished.
Just want to say I admire you continuing in Sisyphean fashion to explain things in an detailed and nuanced way in the face of overwhelming deliberate ignorance and people who will wade into arguments after only listening to a tiny part of the video. I have learned a lot from your channel over the years!
All while ignoring the elephant in the room. The costs. The lack of electric generation capacity. There are 10s of millions of homes in the US that have either gas or oil heat in places that get very cold. The US uses 350 million gallons of gasoline a day. There are hundreds of new planned data centers in the US, yet to be built. We simply do not have the spare capacity for all this stuff. On top of that, there are forces trying to retire nuclear and coal generation. Even over a 20 year time frame, this is simply not feasible.
@@Ultimaximus I work on nuclear reactors, and the massive propaganda campaign against nuclear power is just mind blowing. So much wrong and fake info about nuclear power is taken as gospel.
@@turtletrimmings But the capital cost of that heat is already paid. The capital cost of building hundreds of new power plants is not. Only certain types of gas fired plants even have the ability to get a minor efficiency gain. The thermal efficiency of even the best gas power plants isn't that great. Going by memory, it's in the low 60s. This is for the best ones. How long will it be before the energy consumed by running the power plant (it has all kinds of ongoing energy costs not related to the thermal losses of the generator), the energy consumed building the power plant and the energy losses of the power plant and transmission losses are offset by the increased efficiency of heat pumps? There are likely still millions of houses where you cannot have a heat pump. My house is one of them. I have no duct work. I have steam baseboard heat with only a single pipe going to each baseboard.
Fan motor bearing wear is negligible compared to reducing compressor wear in regards to it always running, just slowing down. Also, as someone working in the manufacturing the compressors in the industry, this and the original vidso are amazing for spreading the correct knowledge and putting it in the hands of consumers to choose their heating. Dont let the internet get you down!
@@StephenByersJ to my knowledge, the only thing between a compressor and 100% duty cycle is primarily lubrication, i.e. plastic compression piston (those just disintegrate immediately) vs an oil submersion compressor, which as long as you cool it appropriately, can basically run for ever.
Love this HVAC series. Another HUGE factor is getting the correct thermostat. If your don't have a thermostat that can handle the system you have, you may draw heat from the wrong system. I found this out the hard way when I got a ~$500 electric bill because the thermostat wasn't correct and called for emergency heat instead of the heat pump. Understand your system! It doesn't take much time to get familiar what what you have and can potentially save you time and money.
You have my sympathy. I'm a mechanical engineer and HVAC is in our competency. It isn't my focus, but knowing and having done the engineering behind it, I don't envy your position as general public educator.
@@blitzwing1 I'm not trying to be snarkey when I ask this: help me understand why brits are against it because you don't have them I don't understand that logic. Get one and decide if you want it? Or, experience one? Are you all just used to being hot and sweaty? The last few heatwaves are examples of what's to come. The trade of a yet higher energy bill is not having heat stroke.
"general public educator". There's your problem right there. Those 3 words should never be combined in the same sentence ANYWHERE!!!!! Frankly I wouldn't trust most of the general public to sit on a toilet the right way round.
@@mattsw104 come to Britain in the height of summer. On *both* the hot stuffy days where ac might improve our homes we generally go outside or open a window. Offices, shops and businesses generally have air con as do many cars. But our homes really wouldn't benefit from the outlay. Unless from a heat pump air con combined unit. But even then it's going to be redundant for months at a time because we don't need heating nor cooling. Edit : by Britain, I mean everything West and North of London. The south east is its own anomaly. From my understanding of the US, you can buy an ac unit in a store and take it home, the cost is low and there's heaps of engineers who can fit one not excluding competent diyers. Here you would have to locate a specialist for everything and that's not going to be easy in most parts of the country.
@mattsw104 I think they meant against heat pumps for heating as they're not familiar with heat pumps for cooling. If I said "flurbledurb" can save you money and help the environment your first response if you're not familiar with the term could be that it's a scam. Personally, UK here and air con is excellent. I stop functioning in the summer without it. 35C and humid overnight for weeks at a time is awful.
@@mattsw104 Brittian doesn't have the temperature swings the US does. It's not as big of a deal there. The US is geographically blessed and climate cursed. The same set of circumstances which lead the US to be home to 75% of all the world's tornadoes also messes up our temperature swing. Let me put it this way. The lowest recorded temperature in Helsinki is pretty close to the lowest recorded temperature in Chicago. Meanwhile the highest ever recorded temperature in Chicago is about 10c higher than Helsinki. Oh, and did I mention Helsinki is 20 degrees further north than Chicago. Chicago just should not be by conventional world wisdom. Our summers are hotter than they should be for our latitude and our winters are colder than they should be for our latitude. The US's climate is cursed. We don't get nice summer days. We get sweltering summer days that cause heat stroke while also getting freezing winter temperatures, in the exact same city. That is not normal for the rest of the world. They get one or the other, not both. Another example. Look at Houston. About once a decade Houston gets a snow storm that wrecks the city. Now go grab a globe put your finger on Houston and spin it, nowhere else on Earth at it's latitude has seen snow in recorded history unless it's caused by altitude, Houston is at sea level and gets snow. Nor have they seen it's record highs.
Hey Alec, I'm an HVAC engineer, I mostly deal with commercial but have a hand in some residential equipment. I specialize in controls but have a grasp of equipment side. Here in AZ there are actually a fair number of homes VRF. You didn't get into the biggest benefit with VRF, zoning. Since its fully variable flow you can run undersized fan coils in each room or zone of a house or building, giving you not only individual temperature control but also finer load control. I.e. if you have a room with your computer that generates more heat, that room will naturally and inherently get more refrigerant capacity. If you really want your mind blown look into heat recovery VRF. Basically it allows the individual zones in a building to go into heating or cooling at any time. This will just take the heat out of one room and dump it into another, not wasting any energy to or from the outside air. Pretty neat stuff.
Also it frustrates me to no end that in ARIZONA, I still see a constant barrage of buildings spec'd for resistive element or gas heat with no heat pump. This is literally the poster child climate for a heat pump. There is no reason anyone in Arizona, especially Phoenix and Tuscon, should not have a heat pump. It just baffles my mind. The price delta is not significant and honestly if I were in charge of my company I would only sell heat pumps if they are spec'd with secondary heat.
@@aristoyotacorner It's been my observation that most commercial HVAC guys keep up with the advances in technology while most of the clowns in residential choose not to. It's the difference between learning the trade and learning some of the tricks of the trade. I feel that residential HVAC is long overdue for a shakeup.
I'm no expert but I thought that non-VRF multihead systems run each head at the same relative capacity. If one room has high load the other area will cycle on and off (like a traditional system) to achieve the needed distribution. Is this not the case? Also, as somebody who has never actually worked with this stuff, I think hydronic systems are better for zoning than VRF. Run one loop at 120F and one at 50F. A zone will open valves to send the required temperature water into its coil and modulation is achieved by varying fan speed. It seems like there's much less that can go wrong compared to VRF, for instance a water leak in one area can be isolated for repair but a refrigerant leak would take out the entire building's heat.
@@eDoc2020 I believe you're right about non vrf multihead systems. I've only dealt with vrf multihead. Water source systems are definitely better for zone control. You lose a lot less energy for long piping runs. This just isn't feasible on a lot of small buildings or houses, as they take up a large footprint even for small capacity systems.
Rest assured, as a licensed professional, I have designed hundreds of buildings in Illinois. Your methods have sunk new principles into my calcified brain.
A good way to explain that a furnace with half the output, running twice as long, produces the same total output is to say "if you want to fill up a bucket, you can fill it quickly from a hose with a lot of water volume, or slowing from a hose with less water volume, but either way you're going to end up with the same amount of water in the bucket." Or to keep the analogy even closer, if we imagine that the bucket leaks a certain amount of water per hour, we can either top it off quickly with the high-volume hose (and then wait for it to leak down more), or take longer to top it off with the low-volume hose (and have shorter breaks between uses), but as long as the hose provides water faster than the leak, the same amount of water is going to be added to the bucket overall (namely, however much water is leaking from the bucket).
Or "the candle that burns twice as bright burns half as long", and the energy in a candle is basically only determined by the amount of wax that it comprises.
This is a poor analogy because when filling a bottle or bucket we want it done fast. EDIT: Ah I get it, it's about total capacity or energy spent. In this way it's okayish. In case of heating it's just to uphold a certain temperature. The only exception being if the furnace turns off overnight and has to reach a certain temperature by a set point in time in the morning. Also that's where I disagree with Alec who calculated for the worst-case scenario a 100% working cycle.
@@VADemon Why do we want to fill the bucket up fast? At no time was that stated to be a goal. If it's going to leak X liters per hour, filling it up "fast" doesn't help at all. And remember, in practice we're not trying to keep the bucket "full" at all times, we're trying to keep it within a certain margin (so we can go a little over the target level, and it's OK to be a little under that level too). The ideal state would be refilling the bucket at exactly the rate it leaks, so it stays at the precise level all the time. Filling it faster just means we wait longer between refills. In fact, if there's a minimum time for the hose to be "on" (that is, we want to avoid short cycles), then having the hose give too much water means that even the minimum time requires a large change in the bucket's level. So we're going to be farther away from the ideal level more of the time. A lower rate of fill would let us stay closer to the correct level: slower is *better*, not worse.
@@trimeta did you get to see the EDIT remark? When you want to fill a water bottle, you don't open the tap to fill 1 droplet at a time. If you want to provide an analogy, don't leave room for interpretation and escapes. Other than that, I am of the same opinion on the subject.
One of your questions was about reliability and wear issues with ecm blowers, and as an Hvac technician, I can answer that. A residential gas furnace with ecm blower will typically require a motor replacement after around 8 years of use. The failure point is the ecm module not the bearings, and the failure is usually in the input section of the module caused by repetitive start stop. On true continuous operation, I can vouch that after 12 years, mine is still working well. Thank you for the huge amount of effort you have put into your hvac videos.
I'll second that. A lot of times it's the varistor that burns up because it's trying to clamp the voltage peaks down. The ECM in our house has run in continuous fan @50% when there's no heat/cool calls for 16 years. It was installed in 2008. Original fan, original motor and original electronics pack. (Trane 19i communicating 2 stage heatpump)
I was thinking about that. At first I thought that running continuously might induce more wear but quickly realized that the start/stop cycle must be way more damaging over time
The furnace in my home was installed in 2009…and the ECM blower has been running continuously ever since…save for power outages and filter changes. It runs at 50% capacity in recirc mode and is nearly silent. Constant start stop is definitely harder than continuous use.
Went to school for HVAC and worked in the industry for a bit. I was lucky to have instructors who went deep into the science of the how and why. They also were very up to date and showed us new technology and how to properly size equipment. Most people who don't go through those classes will never learn except if they do their own research. That's why I love your videos and how you describe these technologies. Anyone who watches these (which should be everyone in my opinion) will leave knowing a lot more of how these machines work and be able to make better and more well informed choices. One thing you did fail to mention though about heat strips (auxiliary heat) is that they are necessary when the heat pump goes into defrost mode. The coils on the outdoor unit during heating will occasionally ice up. During that time, the unit will switch to cooling mode to warm up the outdoor coils. During defrost, the air handler will turn on auxiliary heat to warm up the air to negate the fact that you're essentially running the system in cooling mode.
They are not required. I'm also a tech. I'm in northeast Ohio and I have a heat pump that has no aux heat. It still goes into defrost as needed and it's not even noticeable. The indoor fan just slows way down.
A couple of people have already replied, but I want to echo them anyway. Heat strips are in fact no longer necessary for defrosting. The heat pump my mom and dad have is better thought of as an overgrown mini-split feeding a very large head. Just like a mini-split, when it defrosts it simply stops the indoor blower, reverses into cooling mode to get ice off the coils, then switches back to heating and turns the blower back on. And you can buy that system without heat strips! They're optional. It is my understanding that because it has an EEV, it can throttle flow and pressures to the point that the heat from the motor windings in the compressor is all that's needed to de-ice the outdoor coil. It doesn't actually need to collect any heat from the indoor coil in the process, so the effect to the user is a short pause in heat output. You even see that in the Ecobee data. If it were kicking on the heat strips, with 15kW you likely would have seen a slight _bump_ in indoor temp with each defrost rather than the dips you see. Now, I suppose it's possible that it's kicking on just a single 5kW strip, but I know for a fact you can install that system without heat strips - in fact, this was something the sales rep was aware of as he said his sister(?) had one installed and they didn't bother with them. I personally wouldn't do that in Illinois, but bottom line some of these advanced central systems really are just mini-splits feeding an air handler rather than a ductless head.
@@TechnologyConnections Nice! Been out of the industry for a while and therefore out of the loop. It's amazing how much things have changed (for the better) in such a short amount of time!
Ever since I installed a 2-stage furnace in Chicagoland in 2019, I encountered an unhealthy amount of people who don't want to understand that there's new stuff out there. It's actually ok to run the fan non-stop at low. It helps "even it out" as I learned. HVAC tech agrees. It ends up acting like an air filter, too.
My dad was very HVAC savvy and he was a big proponent of non-stop fans back in the 1970s. We lived in a house with warm water baseboard heat that he designed in the 1960s, so couldn't take advantage of it - but that was the most comfortable house I have ever been in.
I just replaced my furnace and my old blower motor was using 400+ watts while my new furnace blower motor uses 45 watts. The whole thing is more efficient in every way.
@goosenotmaverick1156 it's mostly just schools that have been required to have a certain amount of makeup air or portable HEPA fithers since COVID-19 reopening happened in fall of 2020.
At least you get to feel superior since there are many people out there who simple cannot grasp simple concepts like this. Even when explained clearly as in this video.
I grasp the consept of a heat pump. It takes heat from outside and pushes it into your house. The way it does this is with taking a liquid that turns into gas at -40C or something around those lines... And compressing it into a liquid. It takes energy for a liquid to turn into gas it doesn't just do it out of nowhere and it gets that energy from outside and you need to dispatch of energy when you turn something from a Gas to a Liquid. That's how it works. But if the ambiant temperature is too low like in My country were it regularely gets to -30C then it gets hard for the Liquid to turn into gas. Or to find enough energy to do so.
You are exactly right when you talked about people mentioning the “ya but what if” scenarios. I get that constantly when I speak to people about new things. Conduction cook tops, electric vehicles….. it is truly unfortunate that we have become a society afraid of progress. A relative was talking about how EV’s can’t work in Canada because it’s so cold. I said Norway seems to be doing fine and they a probably cold too (yes with a sarcastic tone). And the whole heating with gas is frustrating. Funniest one was someone telling me that they switched all their lights over to LED and they increased their power consumption. Absolutely ridiculous. But they completely believe it. I’m really glad you did this follow up. I understand what you mean about forgetting about other people’s knowledge levels. I have an EV and found your episodes about them extremely interesting but I have had friends, relatives talk to me about them and really need further information because it’s not their experience yet.
I was in the process of replacing all the 60 year old jalousie windows on my house, and I had an HVAC salesman come to my house for quotes on a new unit about a year ago. I was pleasantly surprised when the salesman asked about any planned insulation/window updates, and even more pleased when he explained all of this and recommended a lower tonnage unit than was previously installed.
Those old windows are a dream come true for the fuel and electricity companies. You need to keep large systems running almost constantly to keep the home warm or cool. Insulation is a more controversial item, adding it to an old structure will often bring lots of unintended consequences with moisture and mold. Most contractors do not understand the basics of moisture control and typically do things that will make conditions worse.
@@davidparker9676 Welcome to Sweden where not only double but now also triple insulated windows are the norm. The best windows today are not far from an insulated wall!
@@davidparker9676Sweden is a long country. In The north you can in some areas have -40C or lower (record low -52,6C). -30C is very common. In The middle -20 to 30C is common. Around the middle of the South, were the capital is, a normal winter can go down to -10 to -20, but also some times down to -30. But here is also often very humid. Going South normal is like -5 to -10 but can go to -20. Also very humid. Some still uses direct electric (radiators). In city areas district heating can be common. Also radiators, or floor heating. A lot of heatpumps, air or geothermal. Geothermal more common in north compared to South. In rural areas some use wood pellets or wood, and using wood in rural as a complement is not uncommon. 70 percent of Singel home houses have heat pumps and over 30 percent of Swedens total heating of all the building are done with heat pumps. Where i live, in a housing cooperative with seven houses each containing 6 flats we have a centralt geothermal heat pump. Comverted from district heating like ten years ago to heat pump. My parentes long ago converted from gas (they were shutting down the grid) to air heat pump connected torsdag water radiators inside. Almost no one uses ducted systems here. Either floor heating, water radiators or mini split air when using heat pumps. There are also exhaust air heat pumps. Then you uses active ventilation and take heat from air blowing out to heat air coming in and Walters for tap. There are models of heat pumps today that are guaranteed to work down to -35C.
@@Xanthopteryx I have a friend that lives in Stockholm but I never thought to ask him what they use for heating. -35C heat from a heat pump is impressive. I like the idea of using geothermal too, I have seen a few people on UA-cam make their own DIY geothermal that seemed to work pretty well.
You did an excellent job on the first video. One small thing to add on furnaces running all the time. Having it run long cycle times also improves the overall comfort of the house by keeping air flowing and stabilizing the temp overall.
You can do this with your current systems as well even if they have shorter cycles, change the fan setting on your thermostats to be set to "on" instead of "auto".
@JonSturm You must have exceptionally low power use compared to average for the fan to be making a big swing on the bill. Not that I personally would go for 24/7/365 as the previous commentor suggested with a dumb tstat set to "on" non stop. Edit: congrats on that low power use by the way. Not hating. Also to say a quick Google tells me you likely have an AC fan motor that uses much more power than my DC fan as well which could lead to the difference.
@@chublezI could definitely see how having the fan always running could be much more expensive if you have leaky duct work, which lots of homes do. If your ducts are leaky, running the fan will be sucking your heated/cooled air out of your living space and into your crawlspace or attic, which would significantly increase your heating/cooling needs
If you don’t understand that you need backup heat, electricity (generator), food you need to stop living day to day!! Things can go wrong it’s your responsibility to be prepared!! Your channel is awesome keep up the good work!!!
hahah after the hour-long video (on a topic you've already touched), a 30min "condensed" version, a wall of text in the community posts, there is still a need for a 40-minute follow up! That's why I love you Alec
21:30 always love when people find "problems" that an engineer also would find and solve, so it's no longer a problem. Like short cycling, "Yes, it was a problem that existed but is solved" is so often an answer.
Similar to people trying to catch "methodological errors" in a scientific study they don't like the results of in the comments under a news article (more often than not things that if you look at the actual paper were of course controlled for one way or another but that fact was not appropriate to the level of abstraction of a 500 word newspaper article)...
@@HunterJEOr the more common error of insisting that a study needs to control for some variable that isn't involved in anything the study was reporting on. I don't have any particular examples, though I did once get in an argument with someone who thought bitcoin was somehow a "store of energy" (like, say, a battery, but with a lot more hand-waving).
@@noyb7920 this is definitely the more common version, people love to claim to see variables the scientists somehow missed... they're always indeed unrelated, as the study treated it lmao
Thank you for your patience, I am getting second hand frustration just from watching this. You are a main reason when our old water heater failed we went with a heat pump model, your efforts in this space are appreciated.
I was in HVAC/R since the late 80's. You are completely correct. I strongly suggested to a home owner to install a 2 stage heatpump in a home in 1990 and found out it just got replaced about 2 years ago. Then I helped install a 2 stage geothermal heatpump in 1991. That one is still running to this day. Although im sure a more efficient one could do very well. I have always loved heatpumps and the tech behind them.
Dont compare the old devices to stuff produced today. The old devices are often better quality than current ones. The old one may be working fine for 30 years (Are they sized to run constantly?!) but current one sized exactly will die on 6-7 years due to wear running non stop. There is a reason why current devices are somewhat cheaper than the old ones. Mass production is a factor but cheap solutions are a factor too. My furnace and AC are 15years old and are loud.
@@answeris4217 It pretty much is the same thing, except instead of venting the heat/cold into the air, you're venting it into the ground. It still is a heat pump, though. I think what might be confusing is the use of the word "Geothermal" instead of "ground-source" heat pump
@@answeris4217 Americans tend to use the term geothermal to mean 'ground source', not, drilling down to get heat from the molten core of the earth, if thats the confusion? If you are still thinking ground source, the tech is the same. its just the heat exchanger is in the ground rather than the air. the tech is basically the same, but a GSHP i more efficient because the tempeature of the ground is more constant, and tends to be closer to the temperature you actually want. plus no defrost cycles etc.
@@answeris4217 As a person that is Certified in the field I know what I am talking about. Geothermal heapump are heatpumps that use a liquid to air exchanger. in some a liquid to liquid exchanger. Also you completely miss the point anyway.
I feel your frustration with people who trust hearsay over legitimate shopping and knowledge-seeking (I won't use the word research, because some people think "research" means go to their favorite propaganda page and read a headline, and at the opposite end of the spectrum others think that it only applies to academics conducting peer-reviewed studies). Ultimately, I think many people just make up their minds and then use whatever they can to justify it, regardless of the legitimacy. I'm always open to being proven wrong and try to integrate new information as much as I can.
People are often far more prone to motivated reasoning than they realise, and then some corners of the Internet attract others who deliberately indulge in it for thrills.
Alec, your outreach and dedication to public education in a way that utilizes the “bring up to speed and then introduce more info” method is both admirable and ACTIVELY improving the state of this country at minimum and the world at maximum. There are not enough people using their platform like you. Congratulations, and keep it up! Love ya.
I have an inverter driven "portable" A/C unit in my home and can confirm, it never* stops running. When I leave home and the setpoint is raised, it turns off for a little bit but then back on at idle speeds as the outside warms up. When I come home and lower the setpoint again, it spikes to full power for a few minutes, then it's back to idle for the rest of the night. I also have a power monitor on the circuit. "Full power" is about 1600W, and idling to hold temperature varies from as low as 200W to as high as 600W when it's really hot outside and/or my gaming PC is running full tilt in the same room. (Which I have to say is pretty good, since the PC will also draw 600W or so at full load.) Also, I'd like to thank you Alec. It's a dual hose unit, solely due to your video on the subject. It's not something I ever would have known without you, and the unit is _remarkably_ efficient.
Inverter-drive compressors are awesome. I appreciate the efficiency, and I just think the sound of an inverter compressor gradually spooling up from off to max RPM is just cool. Pun intended!
@@LatitudeSky it's a Midea 14k BTU/h unit. Model MP12SVKBA3RCM. Edit: for reference, the room is about 125 sq. ft. in a basement with 2 medium windows, neither of which receive direct sunlight. The door is always (except enter and exit) closed. And there is a constant heat load of 300-500W from my server rack, plus the ~600W from my gaming PC when it's in use. The unit is way, way, way more than sufficient for the space. There was a smaller model available from the same brand when I bought it, but it was only 10% or so cheaper so I didn't think it made sense. In the future, I may consider moving this unit to the main (large, kitchen + living + dining, room) and putting a smaller one in here. The exact model number might vary between countries. They actually make this exact unit as a reversible heat pump, according to the manual, but it isn't available in Canada. (Maybe its cold-weather performance is garbage, idk.) It didn't matter to me, because the room it's in never needs additional heating. Fair warning, I do have my gripes with it, but they're mostly minor and I'd still buy it (or other Midea units) again. There may or probably is better available, but having one with a wifi connection that could be controlled locally (it's on wifi but can't reach the internet) was a top priority for me. Canadian Tire had two dual-hose brands available and the other didn't have any network connectivity so I went with this one. Edit: Midea makes a cool window mount unit that they call U-shaped, so the inside and outside portions are normal sized, but the window only needs to be open a couple of inches for the refrigerant piping. If I didn't live in a basement where all the windows open on hinges instead of tracks, I'd give that one a shot too for sure. (The hinged window is an issue for the hose unit too. I had to fabricate a custom shroud that covers the entire window because the provided materials were designed for sliding windows only.)
@@aspecreviews it is kind of a cool sound. Tbh, it's a bit annoying (during the ramp up only), but the Eco preset makes it ramp up so slowly that that noise goes away. If it were in a bedroom, I'd leave it on that preset or at least switch it to that at night.
been looking into an inverter AC just for the ability to soft start so i don't have to turn off other big loads on the inverter/generator whenever it kicks on to avoid overloading it.
Hi!!! You seem kind of stressed out here and I just wanted to let you know that as a person raised without knowledge related to appliances/home stuff, your channel has been super helpful for learning about the things we use in our home everyday. I really appreciate you sharing your knowledge in a way that is entertaining and easy to understand. Also, having context for stuff makes it even easier to understand! No one I know has a house so we can’t act on the heat pumps quite yet but! We have all converted to powder dish detergent and use the pre-rinse lol Anyway tldr you’re cool you’re appreciated and I at least can tell that you are always coming from a place of care for people and our world 💖
@@shrededpudding5921 Even my fridge are inverter based and regulate the speed. It slowly ramps up and mostly it runs at a very low speed, and sometimes even slower so you can actually hear the speed! (like an old ignition ball engine).
I just had my 17yo heat pump replaced earlier today. Can confirm, the aux heat does work when the exterior unit fails. Can also confirm HVAC replacements are expensive
I am so glad you made this follow up video. Short cycling is the death of most compressors. As an automotive repair shop owner, I see plenty of compressors that go bad due to either loaf refrigerant which causes short cycling, or a clog in the system that causes short cycling due to high head pressure. Some cars are even designed to this engage the compressor cycle altogether during a short cycle event to save the compressors life. Automotive systems that are newer, have continually running compressors that variate the level of refrigerant being pumped through the system so far I have not had to replace one at my shop, great job explaining as always!! People reading also need to realize that when the system calls for heat or cooling, that demand has to heat up, not only the air in the space, but also the items in that space, so the heat comes on, and it heats up the air, super fast because your system is over designed short cycles, preventing all the items, maybe your bed, to get warm efficiently.I think per your video, I’m going to install a reversing valve on my current HVAC system and see if I can step away from Gas myself (as I sit in front of my gas fireplace haha) keep making great videos!
Interesting point near the end of the video. I can confirm that in my "dumb" apartment building when the sun is hitting the south side of the building, even in Feb, people in those south facing units are opening patio doors to cool off while on the other side of the building people have their baseboard heaters running at full blast because the only option is either on or off. A system that took the cool air from the shady side of the building and hot air from the sunny side of the building and switched them for free (or nearly free) would be absolutely amazing for everyone.
After reading your comment, I had to revise my opinion about our building codes, specifically the part that states that fully north-facing units are not permissible. It's so much easier to move heat around within one apartment by, um, leaving the doors open, for example.
I have a brand new 3.5 ton heat pump installed last year and I can tell you you’re 100% right. We have had no need for our secondary gas heat, even in negative temperatures. The system is highly efficient, consuming significantly less than our previous 2007 era unit. We did see an efficiency loss when it was down around -8, and it ran a defrost cycle more often, but it kept working fine. Our unit is rated for -15F but we have the controller set to about -10F. We have an older unit for our upstairs that I am highly considering upgrading. Plus if you look into distributed units there are significantly more options available with in-line duct units, wall units, drop ceiling units, etc.
I'm not a HVAC expert, but I spent several years operating/maintaining some large refrigeration systems, so I have a pretty okay grasp of how the technology works and how sizing/etc is important. I'll be installing heat pumps in two locations this spring, and I found these videos great as a refresher and 3rd person PoV to help guide the actual purchase.
I'm amazed the market is still using fixed speed / on-off cycling compressors; for 25 years in Sweden the split system compressors has been inverter/variable speed controlled to meet the load/demand. I installed my own in 2005, still ran fine in 2020 when I had moved out.
i can tell from the graphs you showed here and in original videos that your parent's ecobee isn't set up optimally for staging. it is upstaging when more heat is not needed and not downstaging. the out of the box settings suck - using time instead of temperature to stage, in the settings can go to manual manage staging, "enable reverse staging" and disable max time limit on a stage - so it will automatically only upgrade if the temp is x degrees below setting and then drop back down to first stage.
It's definitely not how I want it (and go figure the techs didn't do anything beyond "auto," but the last time I dug into the staging settings I couldn't make heads or tails of some of the metrics. Sounds like "enable reverse staging" was what I missed - thanks! I'll play around with it more when I get a chance.
you have to set it to manually manage staging or something. i haven't done it on a heatpump but only with a furnace. that contractor initially refused to connect w2 and just use the furnace board's timer and to add insult to injury jumpered w1 and w2 so it was locked on high heat thinking that is how to enable the board's timer. @@TechnologyConnextras
@@Jon-hx7peoh for fuck's sake. it's so insulting that you pay for new technology and the people who are selling it to you can't even be arsed to read the instruction manual.
that's the way it is. the people installing physically know how to install much better than you or i - but they know little about the equipment because they don't read manuals or attend training.@@evilspoons
I had a gas fireplace insert in Colorado. It was not the usual kind of fireplace insert -- it actually stuck out into the room. The way it was constructed, most of the heat actually stayed in the house instead of going up the flue. It was notably small, but I don't know its output rating. The house was "split level", basically a 2-storey house that was sunk into the ground about halfway of the lower floor. You came in the front door or garage, and went down a half flight of stairs to the lower level or up a half flight to the upper level. The fireplace was downstairs. There was at least one time in the 16 years I lived in that house that there was an extended power outage, more than a day, when it was 16°F outside. The insert had no thermostat, only a variable manual gas valve, and a piezo ignition. It kept us quite comfortable during the power outage.
So first... I will say, as a power plant systems engineer with a graduate degree in heat transfer and thermo and nearly 20 years experience, your first video made me grind my teeth a few times, BUT I've watched a lot of your videos. I took a deep breath and let you keep talking, and I can't recall any instances by the end where I was super concerned with anything you said... except the high run time on compressors and fans at design limiting loads. However, you explained your thinking here in the connextras video in a way that, as always, is reasoned, insightful, and humble. You would have made a great engineer, Alec. Keep up the good work.
I THINK he was some kind of engineer in the past. Somewhere, I believe I read he did stuff like work on elevators and other large-scale industrial devices. I'm sure he wasn't an HVAC tech, but he has a background in some kind of mechanical and electrical engineering; don't quote me on that, mind, but I'm fairly sure I remember that.
@@ZangamarthHis background is hotel management (edit: or at least that's what his last job was before he could afford to do creator thing full time, he talks about it in one his videos a few years back). Nothing wrong with that, just what it is. At this point, I'd trust him to do work with me more than I do most of the people I work with.
One thing to know is that Variable flow compressor heatpumps, or as they are known here "inverter reverce cycle air conditioners" are more efficient when under loaded, and can run continuously with as little as 15% of their rated load. As such, for these, a slight 20% over rating so they can meet extreme events is potentially a worthwhile thing, if it puts your highest usage period into the more efficient center part of the AC power range. Separately, in most new installs a separate central dehumidifier is often more efficient, and cheaper than oversizing your heatpump for the load. It is almost always a better idea tonseparate concerns, this means: 1. having a heat pump for climate control (preferrably mini splits for greater efficiency) 2. Having a humidity regulation system with integrated humifldification and or dehumidification. 3. Having a system to remove and replace stale air, with new, filtered clean air in an efficient manner. This should probably include an energy recovery ventilation exchange membrane. These three together, when combined with air tightness and insulation will provide the best outcomes, and dont have to greatly increase costs. Also note that here, general VRF systems are used in many houses as a part of a "multi-split" system. These are not too much of a price adder, as the only additional cost is a few servo valves, and those are only a couple hundred dollars total in the whole system, not a hug price adder.
My dream setup is something like what you described. How beautiful it could be if builders and A/C companies moved forward instead of just getting the easiest thing.
A heat pump already is a dehumidifier, so you don't really need the second one. A basic external exhaust fan will cover the third requirement...or just occasionally opening a window
@known1443 A heat pump can dehumidify, and some of the better dehumidifiers are heatpumps, however. The maximum dehumidification of a heat pump is the saturation point of the indoor radiator. This means that to reduce the humidity below the 100% humidity level indoors you must reduce the temperature of the indoor radiator substantially below the desired indoor set temperature and pump that heat against the indoor outdoor delta-t. If you have a heatpump in the air handler of a ducted hvac system, you often have to do this anyway, but with minisplits, you can have substantially larger indoor coils, with larger surface areas that don't need to go that far below the desired temperature, increasing efficiency. However, this does limit the capacity for air dehumidification somewhat. Further, to use a heat pump with coils inside and outside the building envelope as a dehumidifier you must cool the air to be dehumidified, and this is not always desirable. There is a workaround where you cool to dehumidify, and then heat the space to regain temperature, but doing so against the delta-t of the building envelope is less efficient. Finally, a heat pump is sized to work for the heat load of the building, not nessisarily for the enthalpy for humidity reduction in the worst case, and it can be that this does not match up. All of this means that it is more efficient, and gives better results to use separate mini-split cassettes in each room for heating/cooling, connected to either individual outdoor units or a shared multi-split outdoor unit and then use a separate dehumidifier on the fresh air system, treating them with a separation of concerns. This does increase the cost of the whole system somewhat over having a single centralised indoor coil in the air handling system, but generally gives better results, especially since you can use smaller ducting to each room for supply and return, as you now only have to supply fresh air, and the return balance, rather than air for the heat load of the building. It also reduces noise leakage between rooms and reduces noise from the hvac system when done well. So basically, you can do it with a single oversized heatpump and a fan return. You really do get a nicer space if you didn't though.
@@known1443 The advantage of an air exchanger system over a basic fan or open window is capturing energy during the air exchange. You can pre-heat or pre-cool incoming air using the outgoing air, reducing the overall energy required to maintain the desired house temperature.
@@missamo80 not to mention you get filtered indoor air, which is significant with the particles produced by internal combustion engines. Also you can get more air exchanges with the same power consumption. Finally there are ervs which also equalise the humidity of the outdoor and indoor air, reducing the requirements for humidity control.
I'm glad you clarified that it's not damaging the motor because I always thought the longer it ran the faster it would wear out so that's definitely good to know. I've been waiting till my current setup goes out and planning on getting a Mrcool and installing it myself. I'm feeling more and more confident that I should be able to do it. And my wife loves your videos, so you actually helped convince her too.
Talking about HVAC is so tricky and too many uninformed people are too opinionated. Thank you through all these HVAC and heat pump videos for explaining it. Even though some still seem incapable of wrapping their head around heat pumps, I think you have still helped push the conversation forward online, thank you
I really appreciate the work you're doing to guide and educate people on a fairly complex and rapidly evolving topic. We replaced our A/C with a heat pump a few years back and it's been, almost universally, an upgrade. We've kept our old gas furnace as an auxillary source, and it's only kicked in a couple of times, in blizzard/polar vortex conditions. Otherwise, it's handled the Canadian winter with aplomb. A few notes from our experience: 1. Make sure the you install the heat pump in an open area, clear of nearby obstructions and overhangs. Our A/C unit was in an open-air enclosure that had plenty of space to run, but we had to change the enclosure's design to allow for proper airflow to and from the heat pump. 2. The heat pump will drip condensate. This is no different from a standard A/C unit, but now it's dripping in the dead of winter (and is exacerbated by meltwater from the defrost cycle). Make sure the water doesn't puddle on your walls where it could infiltrate, and beware of ice slicks. Drainage is important. 3. The heat pump blasts hot air in summer and cold air in winter, obviously. Don't put anything super temp-sensitive in the airflow path. 4. The single most improtant part of your system is your thermostat. I'm not a big fan of 'smart' devices, but a thermostat with comprehensive controls, especially one that can run the fan at regular intervals to circulate the air in your house, will drastically improve your home's general comfort level.
We were even told our heat pump would be an "9 months of the year" system and we'd need to rely on the furnace when it gets really cold. Frankly, except for a couple days the year before when we had a cold snap down to like -10 F, the heat pump has worked great and the furnace only needs to run for the hot water
Thank you! You are the reason that we purchased a heat pump to replace our old electric furnace about 9 months ago. Not only has it kept our house delightfully cool all summer, but also toasty warm all winter, but our electric bill has gone down by over $60/month since we installed it. That's the bottom line for me, my wife is always comfortable and and we spend less month in and month out. I have noticed that even though last summer was marginally hotter then the summer before and this last winter was a bit colder, we use about 40% less electricity month for month. Again thanks!
Thank you for both the main channel video and this one. My house is 20yo in CT. Furnace is original (NG forced air) and the central air is 10yo. I'm hoping to retire in a few years. So I'm giving serious consideration to replacing the furnace and AC with a new heat pump system. So thank you for the education!
so, I am from Minnesota. we have a cabin up nort, at that cabin we installed a heat pump in conjunction with a propane fired furnace that runs off of a 500 pound bottle by the road, the heat pump all but eliminated the furnace. this last year, we didn't fire the furnace once, it was insane, and we used that cabin all the way into late October. the last time the furnace was lit was last winter when we went up there to shovel the roof off because of the insane snow load. it's to the point now that my father, who is an HVAC expert, is considering removing the propane furnace and installing a resistive heating backup system.
Now, if you were in a crappier townhouse or a crappy apartment complex, there might well be heat bleed between the dividing walls; some places have undoubtedly just used interior-grade walls to divide the units. I certainly wouldn't be surprised if that was the case at an apartment complex my family lived in from 2000-2008. And I agree that heat pumps are the future. If they aren't the future, we don't _have_ a future.
And he hasn't even scratched the surface. What if I told you that some of the mini-splits can power down to 5-10% of their peak power and achieve COPs of over 10 when temperatures are above 7℃. And of course using the same heat pump for both residential heating/cooling and domestic hot water all in one!
Hi, just so that you know. I'm a consultant M&E engineer working in England. I have designed maybe 10 houses with VRF air to air systems. Some of them have air source heat pumps as well to do heating with underfloor heating. So residential VRF is a thing. I stuggle a bit with your BTUs and Therms, I left those units behind in the 1970s. I admire your efforts to explain how complicated this is, I've been doing it professionally for 45 years and I'm still learning. Well done.
Having learned something every day for the last 60+ years, I have often been puzzled by someone's lack of curiosity. Your willingness to learn and to pass that knowlege on is commendable. Having renovated homes for 17 years, I learned that solar gain, exceptional insulation, and efficient use of heating/cooling are important in that order. Our house is "south facing", has R44 walls and 1 1/2 small wood heaters. We have had -23 celcius rarely but winters can have -10 steady for a week. Summers can have a run of 30 degrees. $650 a year for heating. $0 for cooling. If our heating needs were much greater, I would be looking at the most suitable heat pump I could find. Thanks for all the work you do in sharing your knowledge with us.
I bought my heat pump, (quite a bit on your exposition,) and I have been UTTERLY happy with it. Rated for 24k at -22F and after having done my calculations for heat loss, it performed EXACTLY as advertised... holding 68F at 6F ambient. (One loses more heat , of course as the temperature goes down...) Having said that.. In these recent two warm-winters.. my heating costs have been no more than $230/ month on an ancient 1100 sq ft house, With a propane fireplace for supplemental that helps to add moisture, (
We keep our house at 69-70degF during the winter and 78-79 during summer. End of Jan and early Feb was very cold, but our nat gas bill was $144 (hot water is also gas). The house is a 2019 construction and has 2,800 sq ft. I don't know why so many people pay so much, to be honest. Maybe they have 80 deg F in winter and 70 deg in summer? I have a utility bill tracker where I record all our monthly bills (water/sewage, electricity, gas, internet and phone). Our COMBINED electricity+gas yearly bill was $2,195, split almost evenly between the two.
@@lukeearthcrawler896 I don't have the luxury of having nat. gas. (Even though a line runs right through the township. Unbelievable, right? (- You'd think they'd force them to provide access, having provided the 100'+ right-of-way) Here in the Northeast, it's typically fuel oil, if you don't have nat gas.
One annoyance with my oversized furnace that only runs infrequently is that when it turns on it gets warm quickly. Too warm depending where you are sitting. And then it waits for it to get cold before coming back on. A graph of the temperature is very spikey throughout the day.
This is a good point! My way oversized furnace does the same thing. I have to close the vents in the upstairs and active rooms, including the one with the thermostat. I've tried cycling the blower fan to move the air around in between heating cycles but it gets obliterated once that bad boy kicks on.
This is what I experience as well, my furnace will never run for more than 15 minutes at a time and it gets super hot, and then when the fan cuts out, it gets cold quickly, and the cycle continues. Id prefer a cooler furnace with longer fan run times to even it out.
@@mangamaster03Some smart thermostats do this as a means of eeking out every bit of energy from the furnace, by manually commanding the fan to run after the call for heat has finished and only shutting it down after they see the temperature stop rising.
Three years ago, we got both solar panels with a home backup battery plus upgraded from "too big furnace + air conditioner" to "right-size furnace + heat pump". The hot water heater is natural gas. Our house's basement is set up as "its own apartment." The main floor's kitchen has an electric stove, the basement has natural gas. The main floor's laundry room has an electric dryer, the basement has natural gas. For three years, our natural gas bill was relatively low. The basement renters didn't cook a lot. About nine months ago, they moved out, and we haven't gotten new renters in yet. At about the same time, our kids (adults) moved out. So for nine months, the only natural gas we used was the hot water heater, and for 1/3 as many people as most of the prior few years. Needless to say, our natural gas bill has been really low since the heat pump was put in. (Averaging less than $30/month.) Until a major storm a couple months ago. It knocked out power for only 2.5 days. Our home battery and solar panels were enough to keep us going, with the heat pump off and the furnace operating as "emergency heat". Plus, we had to cook in the basement natural gas oven. Our last natural gas bill was $150. Our electricity bill wasn't lower by $150.
I thought you were clear enough with long cycles not being damaging to the systems, but I appreciate the extra info here. you're absolutely right to be passionate about this stuff, there's not a negligible amount of energy that goes into heating homes, so it's super important to get this right
Ever hear of a Heat Recovery Unit (HRU)? These are simple units with extra heat from the compressor unit of an AC system and use it to heat your hot water. Effectively free hot water whenever the AC unit is running. These work best in areas that need a lot of air conditioning. Homes waste a lot of energy. Another example is your refrigerator and freezer pumps heat into your home, and if the home is too hot, you spend even more energy in the AC system pumping it outside. Homes should be designed with a heating and cooling system that can take advantage of these things and be more efficient.
A good way to explain the energy/power thing may be refilling a leaky pool. If the pool is losing x litres an hour and you fill it with a hose that has x capacity, you just run the hose constantly, if you use a hose that has 10x capacity, you only run the hose 1/10th of the time, but just as much water is still leaking from the pool and just as much water is being replaced. Don't know if I mentioned this in my comment on the original video, but in apartment buildings often wind direction and airflow can also have a substantial impact, particularly older ones where they are not sealed very well from wind, the windward side will usually sustain most of the heating load while the downwind side leeches by the draft of warm air coming through the building. As an aside, it would be interesting to see the efficiency of these variable output compressors at different power levels, I would imagine they become less efficient through some of the range.
The fact that this is new to so many is amazing to me. My family in Canada installed heat pumps in their current home in 1987 with zero issues to date.
Loved this whole series. It made me go back and calculate how much my furnace is running (I have emporia monitor on all my circuits). Turns out my 80,000 BTU furnace only needs to run 58% of the time on the most recent day with an average temp of 0 (65 Heating Degree Days). Thus I only need 46,700 BTUs @ 5 degrees below the design temp for Detroit! Now I know that I need one size smaller furnace if I end up needing to replace it. And I have proof!
@@thezfunkThey just fit within the panel. Its an old panel with only 14 circuits in use. I have a thermal camera that I used to be sure it wasn't creating an overheating danger.
We have a vrf dual fuel system that we put in 2 years ago. We love it. Your original video totally lined up with all the research that we did, and what we were taught by our hvac guys. So here we are, in northern Indiana (very close to the Michigan border) with a heat pump and a gas furnace for the coldest nights. The variable speed works really well, keeps you comfortable, and you can actually hear the (relatively quiet) unit ramp up and down, depending on load. Ours doesn’t run 100%, but it definitely doesn’t run full blast most of the time.
I wish I had this video (and the previous one from the main channel) last summer when I replaced my AC/Furnace (TX). We went with an inverter system and the sales-person grossly oversized both the furnace and AC. I asked about doing a heat pump instead of a furnace and the price was insane which didn't make sense to me because I knew that an AC is a heat pump running backwards. It was 110+ºF and I didn't want to argue, I just wanted my AC to work. Moving from a single-stage to an infinitely variable (actually 1024 stage) system did reduce my electric consumption quite a bit. I understood your points in the original video. I'm sorry people didn't follow you, that's on them. Keep up the good work.
It's so weird that American installers rip you off by charging so much more for a heat pump. Where I live nobody would ever buy an A/C only for their home.
Fun tidbit about bearings. I worked in power plants for years and think about it for a moment. Main bearings on generators are spinning 24/7 for months, even a year or more at a time. They last just fine. In fact, when starting/ stopping, we started special oil pumps called 'lift pumps' to help avoid metal-to-metal contact when starting/ stopping. So yeah, spinning for hours on end isn't a problem for a well designed mechanical system.
A pumped hydro-electric storage facility I have been to has a spare-bearing in stock; the expected life of the first bearing is 50 years; that runs-out in 2028. They spin the thing virtually all the time to stabilize the grid, even when it is not pumping nor generating - i think they called that 'making bars' for some reason. [power-factor?, bar-charts?] To spin it 'dry' [of water] they fill the chamber with compressed-air to drive water out the bottom of the 'bell'. The total weight of the spinning unit is 150 Tons. Bearings LAST!
You are making an incorrect connection here. The dynamics of bearings in a power plant have very little to do with the roller bearings employed in your furnace. The primary failure mode for these small light duty bearings is a failure of the shielding which allows lubricant to leave or debris to enter. They almost never fail through the stop start stop skidding dynamics of the rolling elements.
It's not even that new! I have worked on many apartment buildings with water source heat pumps. They generally have an in unit heat pump, which rejects or absorbs heat from the water loop, then a chiller and a boiler keeps the loop around a design temp.
Sadly as far as I know, no-one does house sized "variable flow with heat recovery" systems, which is why it was mentioned only in the context of apartment blocks. The smallest system I've found so far has an outside unit that's about 1 cubic meter (around 3x3x3 feet) which wouldn't be acceptable to most home owners, and would be seriously over sized for anything but the largest homes. *8')
Dual Fuel makes a ton of sense in a ton of regions. Had one in my last home, and I plan to put one in my new home too. All the efficiency of a heat pump for 300+ days of the year, and gas for the worst cold days and as an emergency fuel (if you know what you’re doing)
Here's an amplification for not oversizing your AC: I had an air conditioner that was grossly oversized that often had its condensate lines freeze. So during hot days, it was entirely possible you wouldn't get any cooling. The Nest thermostat I had was extremely frustrating to work with too.
I am so happy you are doing this. I am in the same boat, I've boned up on hvac and have been doing major retrofitting and have revitalized my knowledge on current cutting edge in insulating, water and vapor management etc, and all the people I talked to, the hvac industry/installers are just not in the same ballpark when it comes to cutting edge according to many many contractors. You are spot on in your comments, and I myself find myself defending myself from various extremely uninformed hvac people. We no longer live in an on and off full steam ahead hvac world. When you're sipping power all day instead of guzzling tons of it two or three times an hour, efficiencies go up. It literally becomes a math problem easily solved. Keep up your great entertaining and informative work
Data center engineers out here still live in the overpowered push lane - pull lane mindset. And they definitely don't grasp the edge case intricacies of "non-condensing". 😂
I got a heat pump last year and have the same trouble explaining it to people. I was so happy for the polar blast because at least it would prove that I did not freeze. It did convince some, not all. BTW, I decided not to get heat strips because the the quoted price was very high. I could buy a lot of space heaters for that.
As a physicist, I approve this message of heat pumps with ">100% efficiency". I think thermodynamics/statistically mechanics is not most physicists strength which might explain why some bristle when people say ">100% efficiency" but you are correct; they can move more energy to than they take to run.
Right the temperature differential created by a heat pump cannot be exploited by a heat engine to run a perpetual motion machine. So no laws of physics (or thermodynamics) are being violated. There's still no free lunch. I realize you already know this, hopefully it will enlighten other readers (but probably just confuse them more)!
Your videos certainly helped my family make the decision to install a heat pump just two weeks ago. We have a 6-year-old gas furnace but a 20-year-old AC unit. I couldn't convince my wife to move to a heat pump 6 years ago when our furnace failed and I'm kind of glad of that now because heat pump tech has changed a lot in those 6 years. And there are financial incentives now that didn't exist then. My wife agreed that we wanted to replace the AC before it failed and so moving to a heat pump system with our gas furnace to supplement on colder days made lots of sense. There is one more benefit that wasn't news to me but was to my wife. Here's how she put it: the furnace would push lots of heat into the house at once while the heat pump trickles the heat into the house regularly and that is an outcome she likes better.
As a Sweden i would say that, yes, things have come along in six years, but not that much. They were really really really good at six years ago too. 20 years ago you could get a heat pump that worked down to -20C. A side note: The first heat pump in Sweden for domestic home was installed in 1948. That is 76 years ago...
Liquified gas is measured by weight or expanded cubic meters (if it was allowed to boil). Propane is almost always measured by lbs in the US. The standard tank for a grill is 20lbs, though 10 and 40 lbs aren't hard to find, either. There are also 1lb bottles for camp stoves, lanterns and heaters. (Flame King produces the only DOT certified, refillable 1lb bottles and you can actually get them 100% filled at home because of their vent system). I absolutely love that I can get away with being a cheapskate on my portable kitchen.
I went all electric from oil. We have 2 heat pumps and are in the northeast US. We have 2 Bosch ids units, one with 15k one with 10k aux heat strips, 3 ton and 2 ton units. Our total heating cost is down, no more oil tank, spending close to the same money but our house is much more comfortable when heating and cooling. The pricing will go down now that these units are set correctly by Bosch. We keep wood for the fireplace, as we did with oil since it didn’t fire without electricity, and a couple space heaters but since this move, we haven’t used either. Good luck with anyone looking to convert. For us it was a huge benefit.
Also, we used two installers, both had taken all the Bosch classes, both set them up wrong and Bosch needed to come out and set them up right. The Bosch rep said many installers still don’t understand how these new units work and anyone should be comfortable calling them for help. Glad we did.
In terms of cold climate heat pumps the Bosch IDS is a relatively poor performer. But on the other hand it's relatively cheap and backed by Bosch. The IDS is actually made by Midea (who makes tons of heat pumps for tons of brands). A no-name like ACiQ might perform slightly better but if something goes wrong you'll be glad you got the established brand.
For old fashion steam heating, if there is a power outage, you can often run them using battery power if you wire into the controller. Many will run on 24V and use around 5 to 10 watts. I have a very one that I have used on battery during a power outage.
@@goosenotmaverick1156It's sometimes hard to explain electricity even to electricians. I have heard so much bullshit over the years from professionals with years or decades of experience.
@@0106johnny i swear up and down to people that we just move magic with (mostly) copper 😂 I once you get deep in the weeds on it, I start to get lost, no lie. So I don't doubt that one bit
@@goosenotmaverick1156 So I should preface with: I'm certified in neither, but I've got a physics degree and a willingness to take things apart, and have taught myself / learned from friends who are certified over the years. And at least in my experience, despite electricity being the more interesting and more likely to kill you if you fuck up, HVAC (Or, I should say, Thermodynamics) is harder to explain to people than electricity unless you're getting really into the weeds of induced voltages and shit no one wants to deal with. Something about the idea that heat is energy is heat just confuses the shit out of people. What do you mean my outdoor air conditioner is hot? That makes no sense, my AC is supposed to be cold!... Well, you see it's transferring the heat energy from your house outdoo... WITCHCRAFT!
People who are THAT worried about the 1% of the time the air source heat pump can't keep up should just look at a geothermal heat pump. They're kind of amazing and they DGAF about what the ambient temperature is, plus you can plumb them to run in-floor heat which is really nice if you have a finished basement or slab on grade. Around here (where it gets way below zero frequently) you can even get a second meter and discounted rates if you install one.
Water always strikes me as a good energy/power analogy. A "fewer words" analogy of the energy/runtime thing is: imagine two buckets of water, one with a large outlet valve and one with a small. How fast will each drain if left open? That's how fast they consume a unit of energy (water). If small one is open all the time and large one is just open and closed periodically, they still use the same energy if all that's needed is a certain amount of water on the output side. Just, one (slower) is a lot smoother at doing it.
The problem is at 1:30 when he says there is no difference in cost in regards to run time. This is true for heat pumps which use only one type of power, but not forced air gas furnaces that require grid power to run the blower in addition to the gas consumption.
Alec, another great series. You can lead a person to a heat pump, but you can't make them use it. This is excellent technology that everyone should be using as soon as possible. It's a no-brainer. Maybe that's the real problem here!!! As I always say, don't take my word for it. Do you own research from reputable sources. You are doing a great service to man kind. Don't give up on us yet. Lol.😊
Just went back and rewatched your LED Stoplights video because of "But Sometimes!" and I gotta say, the jacket really does work for you! Glad you kept keeping it!
I live in northern Minnesota and bought an XC95m 97.3% fully modulating 80,000 BTU furnace, and looking at the matching 2 ton XV20i heat pump. The furnace is fully modulating between 32,000 and 80,000 BTU and the heat pump would be 6,000 to 24,000 BTU (they do have a 3 ton option as well). The seller / installer was not familiar with fully modulating furnaces, as was the case with every local heating company, and initially installed it without the communicating thermostat. This made my fancy furnace a simple 2 stage, not even a 3 stage... I demanded they install the proper thermostat, that they then wired as 2 stage, again. I re wired it as communicating and setup the features myself, blowing the mind of their senior service tech. So happy with the added comfort level. During the cold months my furnace runs about 18 hours a day, mostly on low, never allowing the warmer / colder air to separate and make cold floors and feet. The short and long is my house is old and drafty, I'd love to fix it all but if I had that kind of $$$ I'd just buy a better house. The old 80,000 BTU 91% single stage could only maintain 64*F in -40* outside temps, hence it being so over sized. The new is still 80,000 BTU but the added efficiency means I can now maintain 70*F at -40* outdoor. One thing I learned during the process of figuring out how to make my house liveable ( single stage was sweat-freeze-sweat-freeze as it cycled ) was how much efficiency is lost during the startup process. To stop thermal shock killing the heat exchanger, they preheat the heat exchanger every time the furnace starts, and most of that heat is wasted. This means short cycling does in fact reduce the overall efficiency of the furnace. I had numbers, but that was back in 2020 and I don't remember the exacts.
I read somewhere that in Norway they often deliberately UNDERsize the heatpump to about 85% or less because it rarely gets cold enough to run, and the extra cost to fully size it never pays back over the life of the system since simply using extra supplementary heating for the few days a year it under performs is cheaper.
That is very logical. But that requires people to do something and use auxiliary heating in the rare situations. Not something a lot of americans seem to be willing to do or able to comprehend.
@@rogerk6180 when heat pumps were introduced all homes were heated with resistive heat, usually panel heaters, electric oil radiators, floor heating or a combination of these. (There’s no gas) so when heat pumps are deployed to a property, there are always plenty of additional heat sources available. Unsure about new builds but I suspect additional heat sources are so ingrained in people’s psyche that it’s just a given that you’d have a couple of resistive heaters sitting around.
@@TheShortStory some homes in nordics have/had oil heating. but anyway, yeah in nordics adding a heatpump is an addition generally. in finland people have them installed and it's the first air cooling device they have as well.
As an HVAC professional in the commercial space, I appreciate your videos! One thing I will add is that the most efficient heat pumps typically come as ductless splits. More conventional package unit heat pumps or split system heat pumps are not as efficient, and typically don’t work as well in the colder climates below freezing. I just upgraded an HVAC system in my house and I knew from the beginning that I was going to get a heat pump, but I will say that I am disappointed with its efficiency below 25°. I’m very happy I chose a dual fuel unit with natural gas (I’m in Nashville, TN - so not all that cold). I will also echo your comment about professionals not keeping up with technology. I had to really push the contractor I was using to get the dual fuel heat pump, and he did not believe the heat pump wood work below 40° or so. Most of these guys are good ole boys who do good work, but are not up to date with technology. That technology typically takes a couple decades to work into residential applications. Also, it is more complex to work on so be ready to look for a contractor a bit longer than you are used to, and get used to spending a little bit more on repairs. Overall, I think everyone upgrading their HVAC system should have a heat pump in some capacity. Even if it isn’t the fanciest unit that can heat at all times, most people will save money with a heat pump 90% of the year.
I always thought "heat pump" made more sense... At least in my brain. We are pumping heat from the outdoors to the indoors, indoors to the outdoors, inside this refrigerator to the outside of the refrigerator, from the air outside the water heater into the water inside the tank, etc....
@@ClaytonDorrissome part of general public would understand "reverse air conditioners" easier and would be less prone to fearmongering rather than with shorter and more elegant "heat pump". It's simply because everyone knows what AC is and it doesn't need explaining, even a single teeny tiny sentence.
@@ВалерийШадрин-л5г Interesting opinion, given my summer electric bill is $480/month to run a heat pump and my winter electirc bill is $90/month to run a not-heatpump aka, forced gas furnace with a $90 gas bill.....
This topic is so interesting to me that even nearly 2 hours of content about it holds my attention for the whole time. I would watch an hour long video explaining to people why turning up the thermostat doesn't make it warm up faster, it just either makes it too hot, or your hvac system is broken.
Not so with variable speed compressor heat pumps! They react to the temperature differential and can dial up the output, unlike most other heating and cooling units.
Also should note that in a system with "aux" heat, often the thermostat will call for aux heat if the temperature differential is over a certain amount. But, at least in common systems, that is a binary: if the difference between the temp and the thermostat is > 2 degrees, aux and main are both running (and it heats up faster); if it is less, then only main is running (it heats up slower, but is much less expensive). It would be nice if thermostats had a "stat!" button or dial, meaning, "I want it this temperature as quickly as possible, no matter how much it costs", and then would only ever kick aux in if the temperature with main (or increase the rate if the temperature with current rate) was going in the wrong direction. Of course, then we'd need parental controls on the "stat!" button ...
Hey, I want to say thank you for this. I’m a mechanical engineer, probably around your age, and I remember learning about heat pumps in school and have touted them since, and that was over a decade ago; they’ve only gotten better since, which you mention. I think this sort of message is super important to get out there and I agree with you on every point. Only comment I’d offer is maybe show a calculation or visual to show why energy and power are different, but that could just make sense to me because I already understand the topic.
The way you described VRF systems makes me think that a single family residential application would be using your own basement as a geothermal heat pump to cool the upper floors. That would be so cool to see in a multi-zone system in the future.
@@3x3-x3x-oXo Exactly. Geothermal isn't really getting heat from underground, but using the huge thermal inertia of a large volume of dirt. If you could build the great pyramid of Giza next to your house and use it for that it would work the same, but I guess just drilling some holes in the ground and stuffing pipes on them is easier!
@@karellen00 They actually do take the heat from the ground. The temperature, at least here in Sweden, increases with 2,5 degree C/100 meter down. And the temperature at 15 meter is the same as the average temperature above ground at that place. So if you have an average temperature at 6 degree C where you live, the temperature at 115 meter below the surface are around 8,5C. Of course, this could vary a bit depending of geology but it is a good estimate to calculate your need.
@@Xanthopteryx Yes, but the heat from the ground is just the 2.5°C at 100 m depth, that alone wouldn't mean much. What you really use is the thermal inertia, you have so much amount of stuff that it would take longer than an year to get to temperature, so the ground stays at the average temperature. That's why you can both extract heat in winter and dump it in summer. To be fair this that I described is low enthalpy geothermal, there is high enthalpy geothermal too, that directly gets heat from the magma, but the places where it's available are only a few, and it's not the kind of thing you use to heat an house.
thanks for clearing that up, for some reason "running constantly" seems bad/inefficient /constantly using power. i dunno any numbers that was just my intuition. if i need to swap out my furnace or AC ill probably get a heat pump with aux heat strips.
Thank you for doing this. Also, conveying that homeowners cant count on contractors to do load calcs, well, for free, and if they do the bad outcome is their fault.
BBQ tanks hold 20 pounds of propane, but the issue with propane, and why you need a big tank, and in a colder climate you need an even bigger tank (or some way to heat it), is vapor pressure. A BBQ tank won't be able to supply enough propane to run most appliances not because 20lb. isn't enough propane, but because propane stops vaporizing at -44F, and if you pull a lot of propane out of the small bottle rapidly, it will freeze up. The larger volume of the 400lb and 1000 lb. tanks have more thermal mass and surface area, which mitigates this. That's why you typically see one or two 400lb. tanks hooked to a 7000w backup generator that probably won't use more than a 1/10th of that in a power outage.
This is important. Propane as a source of heat only helps if you're rocking a 100lb tank or bigger because of vaporization. At that point you better have enough land. Who would do that in the suburbs?
I was actually aware of this problem (propane itself is a refrigerant!), but I was talking about storing smaller tanks indoors. Some might not be OK with that (understandably) but even then there are plenty of ways to fix that problem besides relying on the thermal mass of giant tanks.
@@TechnologyConnextras I used to have a tank heater blanket on a 400 lb tank which was meant to be used with a thermostat to keep the tank ready to go, but since I was off grid I would only power it when the generator was running to keep the pressure up. I've since switched to diesel because it's just easier to get the fuel up to the cabin but you could run everything you need in a house off propane if you wanted to.
@@TechnologyConnextras I still have issue with the recommendation of using propane over natural gas. It's like 3x as expensive and course needs to be filled unlike NG which is piped directly into your house. I still haven't heard a compelling argument to ditch NG in favor of heat pumps or electric heat.
@@rob21 unless you live somewhere that has absurdly expensive electricity and absurdly cheap natural gas, an efficient heat pump will produce the heat cheaper than gas unless outdoor temperatures are very low. And he mentions the propane as being for emergency/worst case scenarios, not as a primary heat source. You can buy a couple grill tanks and keep them saved for the few days a year at most that they would be necessary. Plus with NG you have to pay a connection fee even if you don’t use any. I don’t know much about it because NG isn’t available here, but $25/month seems normal from comments I’ve seen here and just by ditching that cost you’ll save quite a bit of money by buying a couple propane tanks for to use on those extremely cold days where the heat pump isn’t enough.
lol I was listening to this in the background, was about to pull into a Home Depot, right as you mentioned Home Depot (note, listening in the background like a podcast, and did not comment while driving.)
These videos explain it to such a depth that only us nerds in the industry know it so I don't blame laymen for not knowing things people I work with still don't understand fully. It's not simple, I've been in the trade for 10 years and I'm still learning as I run into new niche pieces of equipment from over decades
Haha, you finally said at the end what I was thinking from the beginning of this video: "But sometimes...!" FYI, unless your heating plant is an old steam boiler that lacks modern conservation and safety technology, your gas heating plant won't work during a power failure. I have a gas heating plant, and here's the order of events that takes place to make it turn on: First, a "demand for heat" is sent from the thermostat. What is a "demand for heat"? It's when the thermostat switches on the 24V circuit that operates the relays that turn the furnace on. And where does that 24V come from? Why, it comes from one of the circuit breakers in my house, via a transformer that steps it down from 120V to 24V. So, no electrical power means no demand for heat, which means the heating plant stays off. But assuming the electrical power is up and running, when the "demand for heat" is received, three more things happen: Since my heating plant is a hot water system, an electric circulator pump is switched on. At the same time, a small motor opens a chimney flue. Assuming the sensor in the flue sends back a signal to start the burner. This activates the safety valve for the gas, which, if the valve detects that the standing pilot is lit (it starts the gas flow, the pilot lights the gas and I start to get heat. My boiler isn't as sophisticated as it could be, so it the safety valve detects that the standing pilot is out, the action stops there, the flue remains open and the circulator pump continues pumping cold water through the system. 😝But the point is, no electricity, no heat, even with a gas heating plant. Modern forced air and steam heating plants make analogous use of electricity, with similar burner activation systems and, for forced air, electric blowers. What happens if your heat pump breaks? Same thing as if your forced air, hot water or steam heating system breaks down, and I have no reason to believe that this is less likely than a heat pump breaking down. I've lived with all three types of heating systems, powered by both heating oil and natural gas, and all have left me out in the cold, so to speak, on multiple occasions. Gas stoves: If you have a modern gas stove, chances are that your gas stove doesn't work if the electric power is out, either. Modern gas stoves, even basic models without whiz-bang features, use electric relays to turn the gas on. This is a safety feature that's supposed to eliminate asphyxiation and explosion risks if the electronic ignition can't work. The days of pilot-lit gas stoves are long gone.
One slight correction: gas _stoves_ in the US don't have safeties. While they won't automatically light in a power outage they can be lit with a match. Gas _ovens_ are as you describe. Almost all* have digital controls and electric gas valves. *Somehow I ended up with an exception. This oddball oven has an intermittent pilot. When you turn the knob it mechanically opens the first valve and the spark unit lights the pilot. From that point it works like a traditional standing pilot system (with a thermal safety valve). Once the oven knob is turned back to OFF the pilot is turned off. If the intermittent pilot it lit by hand it can be started and used 100% without an electrical connection.
Technically true - but missing the reality and he addresses it at the very start 4:14 Backup power for a GAS system just needs to provide enough power to turn the fan. Which is 1/10 of the power to run a heat pump. Personally (and true for our Host) I can pull enough power from my BEV car to run a gas furnace, a few lights, and a fridge. Enough to get through a winter power outage.
I forgot about the anecdote! So here it is:
I was helping a friend get quotes for a furnace and AC replacement. The sales rep claimed that a two-stage furnace "would cut your heating bills in half because unless it's really cold, it only needs to run at half-power!" which is _flat out wrong_ and incredibly misleading. The furnace would have to run twice as long to produce the same heat! You cannot imagine how livid I was at this rep - I nearly kicked him out of the house.
You may imagine that this incident is a big part of why I get cranky about HVAC companies. At best, this sales rep was woefully misinformed, and at worst - he was lying to try and upsell my friend. I made it clear to this sleazeball in no uncertain terms that what he just said was incorrect and he had better not be using that line on any other person ever. Needless to say, that company did not get the bid.
But the company who did? They're the ones who put in a three-tonner when that house needed, at most, a 1-ton. I had set up a little 5k BTU/hr window unit for that friend and it was holding its own when it was over 90° out. Now the new system cannot dehumidify effectively and a separate dehumidifier is needed to keep the home comfortable. I'm cranky for a reason, is all I'm saying.
I *can* imagine, and I will!
Wouldn't running the furnace for twice as long (at half max output) use twice as much electricity to run the blower fan? Even though you're using the same amount of gas and getting the same amount of heat? It's not much, but that's still efficiency lost.
This type of sales tactic was one of the reasons why I got out of residential HVAC and went to the commercial side. I like helping people and doing right by them.
You can explain it like water you have a valve turn on halfway it runs twice as long or a valve that's turned on all the way runs for a short period time both fill up the same amount of water just different times elapses
Tech temp on space heaters when the season's over blow them out and then stick them in trash bags when you store them this keeps them nice and clean and efficient for next season and doesn't smell like dust burning off when you first turn them on
Did I really just sit and watch a 41 minute addendum to the 65 minute video you put out about something I already knew already? Yes I did.
No regrets. 🙂
And I will too.
Same lol
Yes, you could also watch the shorter one to see if it's better to send your friends and family like i did, but then everyone watched the longer one.
Watching Alec patiently explaining the bleeding obvious to people he really shouldn't be wasting his time with, is like watching Road Runner. You know he's going over the cliff, but you watch and laugh anyway.
A lot of people have zero concept of how much energy different kinds of things actually use. They'll worry about leaving a light on somewhere, but leave the oven preheating until "Wheel of Fortune" is over and not give it a second thought.
And then of course, if it's winter time and your home is reasonably well insulated, that extra preheating time doesn't really matter. That heat will just disperse into the rest of the home anyway.
@@OrigamiMariewait until you hear that some stoves vent directly outside
well, if it's a gas oven....
I see you've met my wife.
@@OrigamiMarie Spend about 8 seconds looking up the efficiency ratings for gas oven heating a room vs a gas furnace and heat pump vs resistive and get back to us.
Just wanted to say my thermodynamics professor loves your original video on heat pumps and shares it with every thermo class he gives. So the message is spreading
As someone who shares the “I must know how this works” mindset, I very much appreciate this channel.
Same lmao. It scratches that part of my brain
The vast majority of people have no idea how the things they rely on, on a daily basis, boggles the mind. How many people need a car to get to work, shop, etc? In the US, most people. How many people know how something simple, like how the brakes work? Yeah, a very small percentage of those same people who rely on that car to live. This makes me scratch my head. This thing is extremely important in your life, and yet you know nothing about it but "put gas in, turn key to start, dur dur dur."
@@jeromethiel4323 I also share the need to understand stuff. I think it might be common to people with ADD (I'm not 100% sure if I have ADD but I think I might, I've just finished testing and will get my results in a couple weeks).
It can be far easier to convince people to switch to electric with a demonstration. My grandmother was absolutely convinced of the superiority of her gas range. Then she saw me use my stove top as extra counter space, then a cutting board, then cook, then clean it all in 30 seconds with a squirt of 409 and 2 damp paper towls.
Absolutely love my induction stove for all those reasons (I have a very small kitchen). The only thing better about gas burners is that I can use a wider variety of cookware - but sorry, that will never offset the rest of the advantages induction brings! It's definitely harder to demonstrate heat pumps, but some before and after data might help convince a few more.
@@bgracey7225 You can get almost all of the advantages without induction. Mine is resistive and can be used with any cookware. The downside is that the glass cook top gets hot and stays hot for a long time after you're finished.
Just want to say I admire you continuing in Sisyphean fashion to explain things in an detailed and nuanced way in the face of overwhelming deliberate ignorance and people who will wade into arguments after only listening to a tiny part of the video. I have learned a lot from your channel over the years!
He single handedly eliminated dishwashing pods for me. Heat pump is a bigger topic but we will get there.
All while ignoring the elephant in the room. The costs. The lack of electric generation capacity.
There are 10s of millions of homes in the US that have either gas or oil heat in places that get very cold. The US uses 350 million gallons of gasoline a day. There are hundreds of new planned data centers in the US, yet to be built.
We simply do not have the spare capacity for all this stuff. On top of that, there are forces trying to retire nuclear and coal generation.
Even over a 20 year time frame, this is simply not feasible.
@@christo930 Does sound like a great reason to increase energy production from nuclear, and renewables, by a whole lot more, doesn't it
@@Ultimaximus I work on nuclear reactors, and the massive propaganda campaign against nuclear power is just mind blowing. So much wrong and fake info about nuclear power is taken as gospel.
@@turtletrimmings But the capital cost of that heat is already paid. The capital cost of building hundreds of new power plants is not. Only certain types of gas fired plants even have the ability to get a minor efficiency gain. The thermal efficiency of even the best gas power plants isn't that great. Going by memory, it's in the low 60s. This is for the best ones. How long will it be before the energy consumed by running the power plant (it has all kinds of ongoing energy costs not related to the thermal losses of the generator), the energy consumed building the power plant and the energy losses of the power plant and transmission losses are offset by the increased efficiency of heat pumps?
There are likely still millions of houses where you cannot have a heat pump. My house is one of them. I have no duct work. I have steam baseboard heat with only a single pipe going to each baseboard.
Fan motor bearing wear is negligible compared to reducing compressor wear in regards to it always running, just slowing down. Also, as someone working in the manufacturing the compressors in the industry, this and the original vidso are amazing for spreading the correct knowledge and putting it in the hands of consumers to choose their heating. Dont let the internet get you down!
plus maintenance is trivial
Compressors are meant to run 100% duty cycle, yeah? Running multiple days straight isn’t a problem?
@@StephenByersJ yes, infact the commercial ones I am working in developing are variable and prefer to run at all times.
@@StephenByersJ to my knowledge, the only thing between a compressor and 100% duty cycle is primarily lubrication, i.e. plastic compression piston (those just disintegrate immediately) vs an oil submersion compressor, which as long as you cool it appropriately, can basically run for ever.
I would rather replace a blower sooner because it ran constantly than replace a compressor because it didn't
Love this HVAC series. Another HUGE factor is getting the correct thermostat. If your don't have a thermostat that can handle the system you have, you may draw heat from the wrong system. I found this out the hard way when I got a ~$500 electric bill because the thermostat wasn't correct and called for emergency heat instead of the heat pump. Understand your system! It doesn't take much time to get familiar what what you have and can potentially save you time and money.
You have my sympathy. I'm a mechanical engineer and HVAC is in our competency. It isn't my focus, but knowing and having done the engineering behind it, I don't envy your position as general public educator.
@@blitzwing1 I'm not trying to be snarkey when I ask this: help me understand why brits are against it because you don't have them
I don't understand that logic. Get one and decide if you want it? Or, experience one? Are you all just used to being hot and sweaty? The last few heatwaves are examples of what's to come. The trade of a yet higher energy bill is not having heat stroke.
"general public educator". There's your problem right there. Those 3 words should never be combined in the same sentence ANYWHERE!!!!!
Frankly I wouldn't trust most of the general public to sit on a toilet the right way round.
@@mattsw104 come to Britain in the height of summer. On *both* the hot stuffy days where ac might improve our homes we generally go outside or open a window. Offices, shops and businesses generally have air con as do many cars. But our homes really wouldn't benefit from the outlay. Unless from a heat pump air con combined unit. But even then it's going to be redundant for months at a time because we don't need heating nor cooling.
Edit : by Britain, I mean everything West and North of London. The south east is its own anomaly.
From my understanding of the US, you can buy an ac unit in a store and take it home, the cost is low and there's heaps of engineers who can fit one not excluding competent diyers. Here you would have to locate a specialist for everything and that's not going to be easy in most parts of the country.
@mattsw104 I think they meant against heat pumps for heating as they're not familiar with heat pumps for cooling. If I said "flurbledurb" can save you money and help the environment your first response if you're not familiar with the term could be that it's a scam.
Personally, UK here and air con is excellent. I stop functioning in the summer without it. 35C and humid overnight for weeks at a time is awful.
@@mattsw104 Brittian doesn't have the temperature swings the US does. It's not as big of a deal there. The US is geographically blessed and climate cursed. The same set of circumstances which lead the US to be home to 75% of all the world's tornadoes also messes up our temperature swing. Let me put it this way. The lowest recorded temperature in Helsinki is pretty close to the lowest recorded temperature in Chicago. Meanwhile the highest ever recorded temperature in Chicago is about 10c higher than Helsinki. Oh, and did I mention Helsinki is 20 degrees further north than Chicago. Chicago just should not be by conventional world wisdom. Our summers are hotter than they should be for our latitude and our winters are colder than they should be for our latitude. The US's climate is cursed. We don't get nice summer days. We get sweltering summer days that cause heat stroke while also getting freezing winter temperatures, in the exact same city. That is not normal for the rest of the world. They get one or the other, not both.
Another example. Look at Houston. About once a decade Houston gets a snow storm that wrecks the city. Now go grab a globe put your finger on Houston and spin it, nowhere else on Earth at it's latitude has seen snow in recorded history unless it's caused by altitude, Houston is at sea level and gets snow. Nor have they seen it's record highs.
Hey Alec, I'm an HVAC engineer, I mostly deal with commercial but have a hand in some residential equipment. I specialize in controls but have a grasp of equipment side. Here in AZ there are actually a fair number of homes VRF. You didn't get into the biggest benefit with VRF, zoning. Since its fully variable flow you can run undersized fan coils in each room or zone of a house or building, giving you not only individual temperature control but also finer load control. I.e. if you have a room with your computer that generates more heat, that room will naturally and inherently get more refrigerant capacity. If you really want your mind blown look into heat recovery VRF. Basically it allows the individual zones in a building to go into heating or cooling at any time. This will just take the heat out of one room and dump it into another, not wasting any energy to or from the outside air. Pretty neat stuff.
Also it frustrates me to no end that in ARIZONA, I still see a constant barrage of buildings spec'd for resistive element or gas heat with no heat pump. This is literally the poster child climate for a heat pump. There is no reason anyone in Arizona, especially Phoenix and Tuscon, should not have a heat pump. It just baffles my mind. The price delta is not significant and honestly if I were in charge of my company I would only sell heat pumps if they are spec'd with secondary heat.
@@aristoyotacorner It's been my observation that most commercial HVAC guys keep up with the advances in technology while most of the clowns in residential choose not to. It's the difference between learning the trade and learning some of the tricks of the trade. I feel that residential HVAC is long overdue for a shakeup.
I'm no expert but I thought that non-VRF multihead systems run each head at the same relative capacity. If one room has high load the other area will cycle on and off (like a traditional system) to achieve the needed distribution. Is this not the case?
Also, as somebody who has never actually worked with this stuff, I think hydronic systems are better for zoning than VRF. Run one loop at 120F and one at 50F. A zone will open valves to send the required temperature water into its coil and modulation is achieved by varying fan speed. It seems like there's much less that can go wrong compared to VRF, for instance a water leak in one area can be isolated for repair but a refrigerant leak would take out the entire building's heat.
@@eDoc2020 I believe you're right about non vrf multihead systems. I've only dealt with vrf multihead.
Water source systems are definitely better for zone control. You lose a lot less energy for long piping runs. This just isn't feasible on a lot of small buildings or houses, as they take up a large footprint even for small capacity systems.
@TechnologyConnextras Pt. 3 incoming?!
Rest assured, as a licensed professional, I have designed hundreds of buildings in Illinois. Your methods have sunk new principles into my calcified brain.
Nothing better than love learning to learn
A good way to explain that a furnace with half the output, running twice as long, produces the same total output is to say "if you want to fill up a bucket, you can fill it quickly from a hose with a lot of water volume, or slowing from a hose with less water volume, but either way you're going to end up with the same amount of water in the bucket." Or to keep the analogy even closer, if we imagine that the bucket leaks a certain amount of water per hour, we can either top it off quickly with the high-volume hose (and then wait for it to leak down more), or take longer to top it off with the low-volume hose (and have shorter breaks between uses), but as long as the hose provides water faster than the leak, the same amount of water is going to be added to the bucket overall (namely, however much water is leaking from the bucket).
Or "the candle that burns twice as bright burns half as long", and the energy in a candle is basically only determined by the amount of wax that it comprises.
Indeed. I was just muttering something similar. (see my main post for the long version)
This is a poor analogy because when filling a bottle or bucket we want it done fast. EDIT: Ah I get it, it's about total capacity or energy spent. In this way it's okayish.
In case of heating it's just to uphold a certain temperature. The only exception being if the furnace turns off overnight and has to reach a certain temperature by a set point in time in the morning. Also that's where I disagree with Alec who calculated for the worst-case scenario a 100% working cycle.
@@VADemon Why do we want to fill the bucket up fast? At no time was that stated to be a goal. If it's going to leak X liters per hour, filling it up "fast" doesn't help at all. And remember, in practice we're not trying to keep the bucket "full" at all times, we're trying to keep it within a certain margin (so we can go a little over the target level, and it's OK to be a little under that level too). The ideal state would be refilling the bucket at exactly the rate it leaks, so it stays at the precise level all the time. Filling it faster just means we wait longer between refills.
In fact, if there's a minimum time for the hose to be "on" (that is, we want to avoid short cycles), then having the hose give too much water means that even the minimum time requires a large change in the bucket's level. So we're going to be farther away from the ideal level more of the time. A lower rate of fill would let us stay closer to the correct level: slower is *better*, not worse.
@@trimeta did you get to see the EDIT remark?
When you want to fill a water bottle, you don't open the tap to fill 1 droplet at a time. If you want to provide an analogy, don't leave room for interpretation and escapes.
Other than that, I am of the same opinion on the subject.
One of your questions was about reliability and wear issues with ecm blowers, and as an Hvac technician, I can answer that. A residential gas furnace with ecm blower will typically require a motor replacement after around 8 years of use. The failure point is the ecm module not the bearings, and the failure is usually in the input section of the module caused by repetitive start stop. On true continuous operation, I can vouch that after 12 years, mine is still working well.
Thank you for the huge amount of effort you have put into your hvac videos.
I'll second that. A lot of times it's the varistor that burns up because it's trying to clamp the voltage peaks down. The ECM in our house has run in continuous fan @50% when there's no heat/cool calls for 16 years. It was installed in 2008. Original fan, original motor and original electronics pack. (Trane 19i communicating 2 stage heatpump)
I was thinking about that. At first I thought that running continuously might induce more wear but quickly realized that the start/stop cycle must be way more damaging over time
The furnace in my home was installed in 2009…and the ECM blower has been running continuously ever since…save for power outages and filter changes. It runs at 50% capacity in recirc mode and is nearly silent.
Constant start stop is definitely harder than continuous use.
I just replaced the blower in our house from a hvac installed in 87. The electro air filter quit working and the dusk plugged up the motor.
Went to school for HVAC and worked in the industry for a bit. I was lucky to have instructors who went deep into the science of the how and why. They also were very up to date and showed us new technology and how to properly size equipment. Most people who don't go through those classes will never learn except if they do their own research. That's why I love your videos and how you describe these technologies. Anyone who watches these (which should be everyone in my opinion) will leave knowing a lot more of how these machines work and be able to make better and more well informed choices.
One thing you did fail to mention though about heat strips (auxiliary heat) is that they are necessary when the heat pump goes into defrost mode. The coils on the outdoor unit during heating will occasionally ice up. During that time, the unit will switch to cooling mode to warm up the outdoor coils. During defrost, the air handler will turn on auxiliary heat to warm up the air to negate the fact that you're essentially running the system in cooling mode.
No they are not.
They are not required. I'm also a tech. I'm in northeast Ohio and I have a heat pump that has no aux heat. It still goes into defrost as needed and it's not even noticeable. The indoor fan just slows way down.
A couple of people have already replied, but I want to echo them anyway. Heat strips are in fact no longer necessary for defrosting. The heat pump my mom and dad have is better thought of as an overgrown mini-split feeding a very large head. Just like a mini-split, when it defrosts it simply stops the indoor blower, reverses into cooling mode to get ice off the coils, then switches back to heating and turns the blower back on. And you can buy that system without heat strips! They're optional.
It is my understanding that because it has an EEV, it can throttle flow and pressures to the point that the heat from the motor windings in the compressor is all that's needed to de-ice the outdoor coil. It doesn't actually need to collect any heat from the indoor coil in the process, so the effect to the user is a short pause in heat output. You even see that in the Ecobee data. If it were kicking on the heat strips, with 15kW you likely would have seen a slight _bump_ in indoor temp with each defrost rather than the dips you see. Now, I suppose it's possible that it's kicking on just a single 5kW strip, but I know for a fact you can install that system without heat strips - in fact, this was something the sales rep was aware of as he said his sister(?) had one installed and they didn't bother with them. I personally wouldn't do that in Illinois, but bottom line some of these advanced central systems really are just mini-splits feeding an air handler rather than a ductless head.
@@TechnologyConnections Nice! Been out of the industry for a while and therefore out of the loop. It's amazing how much things have changed (for the better) in such a short amount of time!
@@langj43 Things always just keep getting better it seems!
Ever since I installed a 2-stage furnace in Chicagoland in 2019, I encountered an unhealthy amount of people who don't want to understand that there's new stuff out there. It's actually ok to run the fan non-stop at low. It helps "even it out" as I learned. HVAC tech agrees.
It ends up acting like an air filter, too.
My dad was very HVAC savvy and he was a big proponent of non-stop fans back in the 1970s. We lived in a house with warm water baseboard heat that he designed in the 1960s, so couldn't take advantage of it - but that was the most comfortable house I have ever been in.
Commercial spaces are required to run continuously circulating systems for similar reasonings, from my understanding.
I just replaced my furnace and my old blower motor was using 400+ watts while my new furnace blower motor uses 45 watts. The whole thing is more efficient in every way.
@goosenotmaverick1156 it's mostly just schools that have been required to have a certain amount of makeup air or portable HEPA fithers since COVID-19 reopening happened in fall of 2020.
I schedule my fan to run on low all day, and it definitely balances the rooms out.
It's still amazes me how many people out there simply cannot seem to grasp simple concepts like this. Even when explained clearly as in this video
At least you get to feel superior since there are many people out there who simple cannot grasp simple concepts like this. Even when explained clearly as in this video.
@@retirementpirate3665 "who simple cannot grasp"
Genius.
I grasp the consept of a heat pump. It takes heat from outside and pushes it into your house. The way it does this is with taking a liquid that turns into gas at -40C or something around those lines... And compressing it into a liquid.
It takes energy for a liquid to turn into gas it doesn't just do it out of nowhere and it gets that energy from outside and you need to dispatch of energy when you turn something from a Gas to a Liquid.
That's how it works.
But if the ambiant temperature is too low like in My country were it regularely gets to -30C then it gets hard for the Liquid to turn into gas. Or to find enough energy to do so.
Alec has an inexhaustible supply of patience that he's tapped into from somewhere. In past centuries he'd be burned for this sort of sorcery.
@@johnrauner2515 also in Florida today
You are exactly right when you talked about people mentioning the “ya but what if” scenarios. I get that constantly when I speak to people about new things. Conduction cook tops, electric vehicles….. it is truly unfortunate that we have become a society afraid of progress.
A relative was talking about how EV’s can’t work in Canada because it’s so cold. I said Norway seems to be doing fine and they a probably cold too (yes with a sarcastic tone). And the whole heating with gas is frustrating.
Funniest one was someone telling me that they switched all their lights over to LED and they increased their power consumption. Absolutely ridiculous. But they completely believe it.
I’m really glad you did this follow up. I understand what you mean about forgetting about other people’s knowledge levels. I have an EV and found your episodes about them extremely interesting but I have had friends, relatives talk to me about them and really need further information because it’s not their experience yet.
I was in the process of replacing all the 60 year old jalousie windows on my house, and I had an HVAC salesman come to my house for quotes on a new unit about a year ago. I was pleasantly surprised when the salesman asked about any planned insulation/window updates, and even more pleased when he explained all of this and recommended a lower tonnage unit than was previously installed.
Those old windows are a dream come true for the fuel and electricity companies. You need to keep large systems running almost constantly to keep the home warm or cool.
Insulation is a more controversial item, adding it to an old structure will often bring lots of unintended consequences with moisture and mold. Most contractors do not understand the basics of moisture control and typically do things that will make conditions worse.
@@davidparker9676 Welcome to Sweden where not only double but now also triple insulated windows are the norm. The best windows today are not far from an insulated wall!
@@Xanthopteryx What are the low temps where yo live in winter? What are you using for heat?
@@davidparker9676Sweden is a long country. In The north you can in some areas have -40C or lower (record low -52,6C). -30C is very common. In The middle -20 to 30C is common. Around the middle of the South, were the capital is, a normal winter can go down to -10 to -20, but also some times down to -30. But here is also often very humid. Going South normal is like -5 to -10 but can go to -20. Also very humid.
Some still uses direct electric (radiators). In city areas district heating can be common. Also radiators, or floor heating. A lot of heatpumps, air or geothermal. Geothermal more common in north compared to South. In rural areas some use wood pellets or wood, and using wood in rural as a complement is not uncommon. 70 percent of Singel home houses have heat pumps and over 30 percent of Swedens total heating of all the building are done with heat pumps. Where i live, in a housing cooperative with seven houses each containing 6 flats we have a centralt geothermal heat pump. Comverted from district heating like ten years ago to heat pump.
My parentes long ago converted from gas (they were shutting down the grid) to air heat pump connected torsdag water radiators inside.
Almost no one uses ducted systems here. Either floor heating, water radiators or mini split air when using heat pumps.
There are also exhaust air heat pumps. Then you uses active ventilation and take heat from air blowing out to heat air coming in and Walters for tap. There are models of heat pumps today that are guaranteed to work down to -35C.
@@Xanthopteryx I have a friend that lives in Stockholm but I never thought to ask him what they use for heating.
-35C heat from a heat pump is impressive.
I like the idea of using geothermal too, I have seen a few people on UA-cam make their own DIY geothermal that seemed to work pretty well.
You did an excellent job on the first video. One small thing to add on furnaces running all the time. Having it run long cycle times also improves the overall comfort of the house by keeping air flowing and stabilizing the temp overall.
He did mention that.
You can do this with your current systems as well even if they have shorter cycles, change the fan setting on your thermostats to be set to "on" instead of "auto".
Running the fan longer is not free and at least with my system does make a noticeable difference to my power bill.
@JonSturm You must have exceptionally low power use compared to average for the fan to be making a big swing on the bill. Not that I personally would go for 24/7/365 as the previous commentor suggested with a dumb tstat set to "on" non stop.
Edit: congrats on that low power use by the way. Not hating.
Also to say a quick Google tells me you likely have an AC fan motor that uses much more power than my DC fan as well which could lead to the difference.
@@chublezI could definitely see how having the fan always running could be much more expensive if you have leaky duct work, which lots of homes do. If your ducts are leaky, running the fan will be sucking your heated/cooled air out of your living space and into your crawlspace or attic, which would significantly increase your heating/cooling needs
If you don’t understand that you need backup heat, electricity (generator), food you need to stop living day to day!! Things can go wrong it’s your responsibility to be prepared!! Your channel is awesome keep up the good work!!!
hahah after the hour-long video (on a topic you've already touched), a 30min "condensed" version, a wall of text in the community posts, there is still a need for a 40-minute follow up!
That's why I love you Alec
To explain HVAC, first you must explain the Universe.
Did someone say latent heat of vaporisation?
Don't overcomplicate it, itz just magic
21:30 always love when people find "problems" that an engineer also would find and solve, so it's no longer a problem.
Like short cycling,
"Yes, it was a problem that existed but is solved" is so often an answer.
Similar to people trying to catch "methodological errors" in a scientific study they don't like the results of in the comments under a news article (more often than not things that if you look at the actual paper were of course controlled for one way or another but that fact was not appropriate to the level of abstraction of a 500 word newspaper article)...
@@HunterJEOr the more common error of insisting that a study needs to control for some variable that isn't involved in anything the study was reporting on. I don't have any particular examples, though I did once get in an argument with someone who thought bitcoin was somehow a "store of energy" (like, say, a battery, but with a lot more hand-waving).
@@noyb7920 this is definitely the more common version, people love to claim to see variables the scientists somehow missed... they're always indeed unrelated, as the study treated it lmao
Thank you for your patience, I am getting second hand frustration just from watching this. You are a main reason when our old water heater failed we went with a heat pump model, your efforts in this space are appreciated.
I was in HVAC/R since the late 80's. You are completely correct. I strongly suggested to a home owner to install a 2 stage heatpump in a home in 1990 and found out it just got replaced about 2 years ago. Then I helped install a 2 stage geothermal heatpump in 1991. That one is still running to this day. Although im sure a more efficient one could do very well. I have always loved heatpumps and the tech behind them.
Geothermal is completely different than heat pumps like the one in the video. A geothermal heater needs to go into the earth.
Dont compare the old devices to stuff produced today.
The old devices are often better quality than current ones.
The old one may be working fine for 30 years (Are they sized to run constantly?!) but current one sized exactly will die on 6-7 years due to wear running non stop.
There is a reason why current devices are somewhat cheaper than the old ones. Mass production is a factor but cheap solutions are a factor too.
My furnace and AC are 15years old and are loud.
@@answeris4217 It pretty much is the same thing, except instead of venting the heat/cold into the air, you're venting it into the ground. It still is a heat pump, though.
I think what might be confusing is the use of the word "Geothermal" instead of "ground-source" heat pump
@@answeris4217 Americans tend to use the term geothermal to mean 'ground source', not, drilling down to get heat from the molten core of the earth, if thats the confusion?
If you are still thinking ground source, the tech is the same. its just the heat exchanger is in the ground rather than the air. the tech is basically the same, but a GSHP i more efficient because the tempeature of the ground is more constant, and tends to be closer to the temperature you actually want. plus no defrost cycles etc.
@@answeris4217 As a person that is Certified in the field I know what I am talking about. Geothermal heapump are heatpumps that use a liquid to air exchanger. in some a liquid to liquid exchanger. Also you completely miss the point anyway.
I feel your frustration with people who trust hearsay over legitimate shopping and knowledge-seeking (I won't use the word research, because some people think "research" means go to their favorite propaganda page and read a headline, and at the opposite end of the spectrum others think that it only applies to academics conducting peer-reviewed studies). Ultimately, I think many people just make up their minds and then use whatever they can to justify it, regardless of the legitimacy. I'm always open to being proven wrong and try to integrate new information as much as I can.
Professor Twitter to the rescue. If I get cancer, that's where I'll go.
People are often far more prone to motivated reasoning than they realise, and then some corners of the Internet attract others who deliberately indulge in it for thrills.
Alec, your outreach and dedication to public education in a way that utilizes the “bring up to speed and then introduce more info” method is both admirable and ACTIVELY improving the state of this country at minimum and the world at maximum. There are not enough people using their platform like you. Congratulations, and keep it up! Love ya.
I have an inverter driven "portable" A/C unit in my home and can confirm, it never* stops running.
When I leave home and the setpoint is raised, it turns off for a little bit but then back on at idle speeds as the outside warms up. When I come home and lower the setpoint again, it spikes to full power for a few minutes, then it's back to idle for the rest of the night.
I also have a power monitor on the circuit. "Full power" is about 1600W, and idling to hold temperature varies from as low as 200W to as high as 600W when it's really hot outside and/or my gaming PC is running full tilt in the same room. (Which I have to say is pretty good, since the PC will also draw 600W or so at full load.)
Also, I'd like to thank you Alec. It's a dual hose unit, solely due to your video on the subject. It's not something I ever would have known without you, and the unit is _remarkably_ efficient.
Inverter-drive compressors are awesome. I appreciate the efficiency, and I just think the sound of an inverter compressor gradually spooling up from off to max RPM is just cool. Pun intended!
Can you share what brand it is? I need one of those things and for a room that also has a gaming PC.
@@LatitudeSky it's a Midea 14k BTU/h unit. Model MP12SVKBA3RCM.
Edit: for reference, the room is about 125 sq. ft. in a basement with 2 medium windows, neither of which receive direct sunlight. The door is always (except enter and exit) closed. And there is a constant heat load of 300-500W from my server rack, plus the ~600W from my gaming PC when it's in use. The unit is way, way, way more than sufficient for the space. There was a smaller model available from the same brand when I bought it, but it was only 10% or so cheaper so I didn't think it made sense. In the future, I may consider moving this unit to the main (large, kitchen + living + dining, room) and putting a smaller one in here.
The exact model number might vary between countries. They actually make this exact unit as a reversible heat pump, according to the manual, but it isn't available in Canada. (Maybe its cold-weather performance is garbage, idk.) It didn't matter to me, because the room it's in never needs additional heating.
Fair warning, I do have my gripes with it, but they're mostly minor and I'd still buy it (or other Midea units) again. There may or probably is better available, but having one with a wifi connection that could be controlled locally (it's on wifi but can't reach the internet) was a top priority for me. Canadian Tire had two dual-hose brands available and the other didn't have any network connectivity so I went with this one.
Edit: Midea makes a cool window mount unit that they call U-shaped, so the inside and outside portions are normal sized, but the window only needs to be open a couple of inches for the refrigerant piping. If I didn't live in a basement where all the windows open on hinges instead of tracks, I'd give that one a shot too for sure. (The hinged window is an issue for the hose unit too. I had to fabricate a custom shroud that covers the entire window because the provided materials were designed for sliding windows only.)
@@aspecreviews it is kind of a cool sound. Tbh, it's a bit annoying (during the ramp up only), but the Eco preset makes it ramp up so slowly that that noise goes away. If it were in a bedroom, I'd leave it on that preset or at least switch it to that at night.
been looking into an inverter AC just for the ability to soft start so i don't have to turn off other big loads on the inverter/generator whenever it kicks on to avoid overloading it.
Babe wake up new technology connextras vid about heat pumps just dropped
Just started playing this video on the TV and my gf got up and left the room lol
@@deankruse8751my wife was like this channel again? 😂
I'm on-call (I.T. job) and everything will be on hold for this video 😉
2 of 4 people in this thread need new partners. ;P
@deankruse8751 well, she maybe doesn't believe it but she got a good bf. You will keep her warm and rich😜
Hi!!! You seem kind of stressed out here and I just wanted to let you know that as a person raised without knowledge related to appliances/home stuff, your channel has been super helpful for learning about the things we use in our home everyday. I really appreciate you sharing your knowledge in a way that is entertaining and easy to understand. Also, having context for stuff makes it even easier to understand!
No one I know has a house so we can’t act on the heat pumps quite yet but! We have all converted to powder dish detergent and use the pre-rinse lol
Anyway tldr you’re cool you’re appreciated and I at least can tell that you are always coming from a place of care for people and our world 💖
Continuing with the "compressor = car engine" metaphor, continuously operating compressors do exclusively highway miles.
Exactly. Inverter systems are kinda like downhill highway miles because they can run at 25% capacity (or lower if you have a light commercial model)
@@shrededpudding5921 Even my fridge are inverter based and regulate the speed. It slowly ramps up and mostly it runs at a very low speed, and sometimes even slower so you can actually hear the speed! (like an old ignition ball engine).
I just had my 17yo heat pump replaced earlier today. Can confirm, the aux heat does work when the exterior unit fails. Can also confirm HVAC replacements are expensive
I am so glad you made this follow up video. Short cycling is the death of most compressors. As an automotive repair shop owner, I see plenty of compressors that go bad due to either loaf refrigerant which causes short cycling, or a clog in the system that causes short cycling due to high head pressure. Some cars are even designed to this engage the compressor cycle altogether during a short cycle event to save the compressors life. Automotive systems that are newer, have continually running compressors that variate the level of refrigerant being pumped through the system so far I have not had to replace one at my shop, great job explaining as always!! People reading also need to realize that when the system calls for heat or cooling, that demand has to heat up, not only the air in the space, but also the items in that space, so the heat comes on, and it heats up the air, super fast because your system is over designed short cycles, preventing all the items, maybe your bed, to get warm efficiently.I think per your video, I’m going to install a reversing valve on my current HVAC system and see if I can step away from Gas myself (as I sit in front of my gas fireplace haha) keep making great videos!
Alec, you DO make the world a better place. Thank you for an excellent episode. Hugs from James and Derek in California.
Interesting point near the end of the video. I can confirm that in my "dumb" apartment building when the sun is hitting the south side of the building, even in Feb, people in those south facing units are opening patio doors to cool off while on the other side of the building people have their baseboard heaters running at full blast because the only option is either on or off. A system that took the cool air from the shady side of the building and hot air from the sunny side of the building and switched them for free (or nearly free) would be absolutely amazing for everyone.
After reading your comment, I had to revise my opinion about our building codes, specifically the part that states that fully north-facing units are not permissible.
It's so much easier to move heat around within one apartment by, um, leaving the doors open, for example.
I have a brand new 3.5 ton heat pump installed last year and I can tell you you’re 100% right. We have had no need for our secondary gas heat, even in negative temperatures. The system is highly efficient, consuming significantly less than our previous 2007 era unit. We did see an efficiency loss when it was down around -8, and it ran a defrost cycle more often, but it kept working fine. Our unit is rated for -15F but we have the controller set to about -10F.
We have an older unit for our upstairs that I am highly considering upgrading. Plus if you look into distributed units there are significantly more options available with in-line duct units, wall units, drop ceiling units, etc.
This put a smile on my face. You're doin' great out there regardless of what people say and I'm learning so much.
I'm not a HVAC expert, but I spent several years operating/maintaining some large refrigeration systems, so I have a pretty okay grasp of how the technology works and how sizing/etc is important.
I'll be installing heat pumps in two locations this spring, and I found these videos great as a refresher and 3rd person PoV to help guide the actual purchase.
Get a variable speed system and never worry about it....
I'm amazed the market is still using fixed speed / on-off cycling compressors; for 25 years in Sweden the split system compressors has been inverter/variable speed controlled to meet the load/demand. I installed my own in 2005, still ran fine in 2020 when I had moved out.
I learned a lot in this video. Mostly to never read the youtube comments.
You can read them for amusement. Not for education.
i can tell from the graphs you showed here and in original videos that your parent's ecobee isn't set up optimally for staging. it is upstaging when more heat is not needed and not downstaging. the out of the box settings suck - using time instead of temperature to stage, in the settings can go to manual manage staging, "enable reverse staging" and disable max time limit on a stage - so it will automatically only upgrade if the temp is x degrees below setting and then drop back down to first stage.
It's definitely not how I want it (and go figure the techs didn't do anything beyond "auto," but the last time I dug into the staging settings I couldn't make heads or tails of some of the metrics. Sounds like "enable reverse staging" was what I missed - thanks! I'll play around with it more when I get a chance.
you have to set it to manually manage staging or something. i haven't done it on a heatpump but only with a furnace. that contractor initially refused to connect w2 and just use the furnace board's timer and to add insult to injury jumpered w1 and w2 so it was locked on high heat thinking that is how to enable the board's timer. @@TechnologyConnextras
@@Jon-hx7peoh for fuck's sake.
it's so insulting that you pay for new technology and the people who are selling it to you can't even be arsed to read the instruction manual.
that's the way it is. the people installing physically know how to install much better than you or i - but they know little about the equipment because they don't read manuals or attend training.@@evilspoons
I had a gas fireplace insert in Colorado. It was not the usual kind of fireplace insert -- it actually stuck out into the room. The way it was constructed, most of the heat actually stayed in the house instead of going up the flue. It was notably small, but I don't know its output rating. The house was "split level", basically a 2-storey house that was sunk into the ground about halfway of the lower floor. You came in the front door or garage, and went down a half flight of stairs to the lower level or up a half flight to the upper level. The fireplace was downstairs. There was at least one time in the 16 years I lived in that house that there was an extended power outage, more than a day, when it was 16°F outside. The insert had no thermostat, only a variable manual gas valve, and a piezo ignition. It kept us quite comfortable during the power outage.
So first... I will say, as a power plant systems engineer with a graduate degree in heat transfer and thermo and nearly 20 years experience, your first video made me grind my teeth a few times, BUT I've watched a lot of your videos. I took a deep breath and let you keep talking, and I can't recall any instances by the end where I was super concerned with anything you said... except the high run time on compressors and fans at design limiting loads. However, you explained your thinking here in the connextras video in a way that, as always, is reasoned, insightful, and humble. You would have made a great engineer, Alec. Keep up the good work.
I THINK he was some kind of engineer in the past. Somewhere, I believe I read he did stuff like work on elevators and other large-scale industrial devices. I'm sure he wasn't an HVAC tech, but he has a background in some kind of mechanical and electrical engineering; don't quote me on that, mind, but I'm fairly sure I remember that.
@@ZangamarthPretty sure he's mentioned before his background is in IT.
@@ZangamarthHis background is hotel management (edit: or at least that's what his last job was before he could afford to do creator thing full time, he talks about it in one his videos a few years back). Nothing wrong with that, just what it is. At this point, I'd trust him to do work with me more than I do most of the people I work with.
One thing to know is that Variable flow compressor heatpumps, or as they are known here "inverter reverce cycle air conditioners" are more efficient when under loaded, and can run continuously with as little as 15% of their rated load. As such, for these, a slight 20% over rating so they can meet extreme events is potentially a worthwhile thing, if it puts your highest usage period into the more efficient center part of the AC power range.
Separately, in most new installs a separate central dehumidifier is often more efficient, and cheaper than oversizing your heatpump for the load. It is almost always a better idea tonseparate concerns, this means:
1. having a heat pump for climate control (preferrably mini splits for greater efficiency)
2. Having a humidity regulation system with integrated humifldification and or dehumidification.
3. Having a system to remove and replace stale air, with new, filtered clean air in an efficient manner. This should probably include an energy recovery ventilation exchange membrane.
These three together, when combined with air tightness and insulation will provide the best outcomes, and dont have to greatly increase costs.
Also note that here, general VRF systems are used in many houses as a part of a "multi-split" system. These are not too much of a price adder, as the only additional cost is a few servo valves, and those are only a couple hundred dollars total in the whole system, not a hug price adder.
My dream setup is something like what you described. How beautiful it could be if builders and A/C companies moved forward instead of just getting the easiest thing.
A heat pump already is a dehumidifier, so you don't really need the second one. A basic external exhaust fan will cover the third requirement...or just occasionally opening a window
@known1443 A heat pump can dehumidify, and some of the better dehumidifiers are heatpumps, however. The maximum dehumidification of a heat pump is the saturation point of the indoor radiator. This means that to reduce the humidity below the 100% humidity level indoors you must reduce the temperature of the indoor radiator substantially below the desired indoor set temperature and pump that heat against the indoor outdoor delta-t.
If you have a heatpump in the air handler of a ducted hvac system, you often have to do this anyway, but with minisplits, you can have substantially larger indoor coils, with larger surface areas that don't need to go that far below the desired temperature, increasing efficiency. However, this does limit the capacity for air dehumidification somewhat.
Further, to use a heat pump with coils inside and outside the building envelope as a dehumidifier you must cool the air to be dehumidified, and this is not always desirable. There is a workaround where you cool to dehumidify, and then heat the space to regain temperature, but doing so against the delta-t of the building envelope is less efficient.
Finally, a heat pump is sized to work for the heat load of the building, not nessisarily for the enthalpy for humidity reduction in the worst case, and it can be that this does not match up.
All of this means that it is more efficient, and gives better results to use separate mini-split cassettes in each room for heating/cooling, connected to either individual outdoor units or a shared multi-split outdoor unit and then use a separate dehumidifier on the fresh air system, treating them with a separation of concerns.
This does increase the cost of the whole system somewhat over having a single centralised indoor coil in the air handling system, but generally gives better results, especially since you can use smaller ducting to each room for supply and return, as you now only have to supply fresh air, and the return balance, rather than air for the heat load of the building. It also reduces noise leakage between rooms and reduces noise from the hvac system when done well.
So basically, you can do it with a single oversized heatpump and a fan return. You really do get a nicer space if you didn't though.
@@known1443 The advantage of an air exchanger system over a basic fan or open window is capturing energy during the air exchange. You can pre-heat or pre-cool incoming air using the outgoing air, reducing the overall energy required to maintain the desired house temperature.
@@missamo80 not to mention you get filtered indoor air, which is significant with the particles produced by internal combustion engines. Also you can get more air exchanges with the same power consumption. Finally there are ervs which also equalise the humidity of the outdoor and indoor air, reducing the requirements for humidity control.
I'm glad you clarified that it's not damaging the motor because I always thought the longer it ran the faster it would wear out so that's definitely good to know. I've been waiting till my current setup goes out and planning on getting a Mrcool and installing it myself. I'm feeling more and more confident that I should be able to do it. And my wife loves your videos, so you actually helped convince her too.
Talking about HVAC is so tricky and too many uninformed people are too opinionated. Thank you through all these HVAC and heat pump videos for explaining it. Even though some still seem incapable of wrapping their head around heat pumps, I think you have still helped push the conversation forward online, thank you
I really appreciate the work you're doing to guide and educate people on a fairly complex and rapidly evolving topic.
We replaced our A/C with a heat pump a few years back and it's been, almost universally, an upgrade. We've kept our old gas furnace as an auxillary source, and it's only kicked in a couple of times, in blizzard/polar vortex conditions. Otherwise, it's handled the Canadian winter with aplomb.
A few notes from our experience:
1. Make sure the you install the heat pump in an open area, clear of nearby obstructions and overhangs. Our A/C unit was in an open-air enclosure that had plenty of space to run, but we had to change the enclosure's design to allow for proper airflow to and from the heat pump.
2. The heat pump will drip condensate. This is no different from a standard A/C unit, but now it's dripping in the dead of winter (and is exacerbated by meltwater from the defrost cycle). Make sure the water doesn't puddle on your walls where it could infiltrate, and beware of ice slicks. Drainage is important.
3. The heat pump blasts hot air in summer and cold air in winter, obviously. Don't put anything super temp-sensitive in the airflow path.
4. The single most improtant part of your system is your thermostat. I'm not a big fan of 'smart' devices, but a thermostat with comprehensive controls, especially one that can run the fan at regular intervals to circulate the air in your house, will drastically improve your home's general comfort level.
We were even told our heat pump would be an "9 months of the year" system and we'd need to rely on the furnace when it gets really cold. Frankly, except for a couple days the year before when we had a cold snap down to like -10 F, the heat pump has worked great and the furnace only needs to run for the hot water
Thank you! You are the reason that we purchased a heat pump to replace our old electric furnace about 9 months ago. Not only has it kept our house delightfully cool all summer, but also toasty warm all winter, but our electric bill has gone down by over $60/month since we installed it. That's the bottom line for me, my wife is always comfortable and and we spend less month in and month out. I have noticed that even though last summer was marginally hotter then the summer before and this last winter was a bit colder, we use about 40% less electricity month for month. Again thanks!
Thank you for both the main channel video and this one. My house is 20yo in CT. Furnace is original (NG forced air) and the central air is 10yo. I'm hoping to retire in a few years. So I'm giving serious consideration to replacing the furnace and AC with a new heat pump system. So thank you for the education!
The gas fired water heaters here require forced extraction to outside the house.
so, I am from Minnesota. we have a cabin up nort, at that cabin we installed a heat pump in conjunction with a propane fired furnace that runs off of a 500 pound bottle by the road, the heat pump all but eliminated the furnace. this last year, we didn't fire the furnace once, it was insane, and we used that cabin all the way into late October. the last time the furnace was lit was last winter when we went up there to shovel the roof off because of the insane snow load. it's to the point now that my father, who is an HVAC expert, is considering removing the propane furnace and installing a resistive heating backup system.
You can use the propane for other things too like clothes drying, hot water, and cooking.
Now, if you were in a crappier townhouse or a crappy apartment complex, there might well be heat bleed between the dividing walls; some places have undoubtedly just used interior-grade walls to divide the units. I certainly wouldn't be surprised if that was the case at an apartment complex my family lived in from 2000-2008.
And I agree that heat pumps are the future. If they aren't the future, we don't _have_ a future.
This is turning into quite the series on HVAC.
And he hasn't even scratched the surface. What if I told you that some of the mini-splits can power down to 5-10% of their peak power and achieve COPs of over 10 when temperatures are above 7℃. And of course using the same heat pump for both residential heating/cooling and domestic hot water all in one!
CED makers like this.
Hi, just so that you know. I'm a consultant M&E engineer working in England. I have designed maybe 10 houses with VRF air to air systems. Some of them have air source heat pumps as well to do heating with underfloor heating. So residential VRF is a thing. I stuggle a bit with your BTUs and Therms, I left those units behind in the 1970s. I admire your efforts to explain how complicated this is, I've been doing it professionally for 45 years and I'm still learning. Well done.
Having learned something every day for the last 60+ years, I have often been puzzled by someone's lack of curiosity. Your willingness to learn and to pass that knowlege on is commendable. Having renovated homes for 17 years, I learned that solar gain, exceptional insulation, and efficient use of heating/cooling are important in that order. Our house is "south facing", has R44 walls and 1 1/2 small wood heaters. We have had -23 celcius rarely but winters can have -10 steady for a week. Summers can have a run of 30 degrees. $650 a year for heating. $0 for cooling. If our heating needs were much greater, I would be looking at the most suitable heat pump I could find.
Thanks for all the work you do in sharing your knowledge with us.
I bought my heat pump, (quite a bit on your exposition,) and I have been UTTERLY happy with it. Rated for 24k at -22F and after having done my calculations for heat loss, it performed EXACTLY as advertised... holding 68F at 6F ambient. (One loses more heat , of course as the temperature goes down...) Having said that.. In these recent two warm-winters.. my heating costs have been no more than $230/ month on an ancient 1100 sq ft house, With a propane fireplace for supplemental that helps to add moisture, (
I only heat the house in the cold months. Although I do wash in warm water. Electricity is 4X the price of gas 6:00 per kWh for me.
We keep our house at 69-70degF during the winter and 78-79 during summer. End of Jan and early Feb was very cold, but our nat gas bill was $144 (hot water is also gas). The house is a 2019 construction and has 2,800 sq ft. I don't know why so many people pay so much, to be honest. Maybe they have 80 deg F in winter and 70 deg in summer?
I have a utility bill tracker where I record all our monthly bills (water/sewage, electricity, gas, internet and phone). Our COMBINED electricity+gas yearly bill was $2,195, split almost evenly between the two.
@@lukeearthcrawler896 insulation. Thats the reason, a new 2019 house will be well insulated.
@@lukeearthcrawler896 Good insulation in your house, I expect.
@@lukeearthcrawler896 I don't have the luxury of having nat. gas. (Even though a line runs right through the township. Unbelievable, right? (- You'd think they'd force them to provide access, having provided the 100'+ right-of-way) Here in the Northeast, it's typically fuel oil, if you don't have nat gas.
One annoyance with my oversized furnace that only runs infrequently is that when it turns on it gets warm quickly. Too warm depending where you are sitting. And then it waits for it to get cold before coming back on. A graph of the temperature is very spikey throughout the day.
This is a good point! My way oversized furnace does the same thing. I have to close the vents in the upstairs and active rooms, including the one with the thermostat. I've tried cycling the blower fan to move the air around in between heating cycles but it gets obliterated once that bad boy kicks on.
Depending of your particular furnace, you may be able to change the firing rate. Find a good tech in you area.
This is what I experience as well, my furnace will never run for more than 15 minutes at a time and it gets super hot, and then when the fan cuts out, it gets cold quickly, and the cycle continues. Id prefer a cooler furnace with longer fan run times to even it out.
Can your thermostat turn on just the fan? That will help balance the heat out.
@@mangamaster03Some smart thermostats do this as a means of eeking out every bit of energy from the furnace, by manually commanding the fan to run after the call for heat has finished and only shutting it down after they see the temperature stop rising.
You do an excellent job, and I find it commendable that you take the time to explain these things, especially when you're not obligated to do so.
Three years ago, we got both solar panels with a home backup battery plus upgraded from "too big furnace + air conditioner" to "right-size furnace + heat pump". The hot water heater is natural gas. Our house's basement is set up as "its own apartment." The main floor's kitchen has an electric stove, the basement has natural gas. The main floor's laundry room has an electric dryer, the basement has natural gas.
For three years, our natural gas bill was relatively low. The basement renters didn't cook a lot. About nine months ago, they moved out, and we haven't gotten new renters in yet. At about the same time, our kids (adults) moved out. So for nine months, the only natural gas we used was the hot water heater, and for 1/3 as many people as most of the prior few years.
Needless to say, our natural gas bill has been really low since the heat pump was put in. (Averaging less than $30/month.)
Until a major storm a couple months ago. It knocked out power for only 2.5 days. Our home battery and solar panels were enough to keep us going, with the heat pump off and the furnace operating as "emergency heat". Plus, we had to cook in the basement natural gas oven.
Our last natural gas bill was $150. Our electricity bill wasn't lower by $150.
I thought you were clear enough with long cycles not being damaging to the systems, but I appreciate the extra info here. you're absolutely right to be passionate about this stuff, there's not a negligible amount of energy that goes into heating homes, so it's super important to get this right
I'm that guy in Minnesota who will get a heat pump, but I'm convinced I won't have a bad experience due to your videos and the Undecided channel.
Ever hear of a Heat Recovery Unit (HRU)? These are simple units with extra heat from the compressor unit of an AC system and use it to heat your hot water. Effectively free hot water whenever the AC unit is running. These work best in areas that need a lot of air conditioning. Homes waste a lot of energy. Another example is your refrigerator and freezer pumps heat into your home, and if the home is too hot, you spend even more energy in the AC system pumping it outside. Homes should be designed with a heating and cooling system that can take advantage of these things and be more efficient.
A good way to explain the energy/power thing may be refilling a leaky pool. If the pool is losing x litres an hour and you fill it with a hose that has x capacity, you just run the hose constantly, if you use a hose that has 10x capacity, you only run the hose 1/10th of the time, but just as much water is still leaking from the pool and just as much water is being replaced.
Don't know if I mentioned this in my comment on the original video, but in apartment buildings often wind direction and airflow can also have a substantial impact, particularly older ones where they are not sealed very well from wind, the windward side will usually sustain most of the heating load while the downwind side leeches by the draft of warm air coming through the building.
As an aside, it would be interesting to see the efficiency of these variable output compressors at different power levels, I would imagine they become less efficient through some of the range.
The fact that this is new to so many is amazing to me. My family in Canada installed heat pumps in their current home in 1987 with zero issues to date.
Loved this whole series. It made me go back and calculate how much my furnace is running (I have emporia monitor on all my circuits). Turns out my 80,000 BTU furnace only needs to run 58% of the time on the most recent day with an average temp of 0 (65 Heating Degree Days). Thus I only need 46,700 BTUs @ 5 degrees below the design temp for Detroit! Now I know that I need one size smaller furnace if I end up needing to replace it. And I have proof!
How'd you jam all those monitors in your panel?
@@thezfunkThey just fit within the panel. Its an old panel with only 14 circuits in use. I have a thermal camera that I used to be sure it wasn't creating an overheating danger.
We have a vrf dual fuel system that we put in 2 years ago. We love it. Your original video totally lined up with all the research that we did, and what we were taught by our hvac guys. So here we are, in northern Indiana (very close to the Michigan border) with a heat pump and a gas furnace for the coldest nights. The variable speed works really well, keeps you comfortable, and you can actually hear the (relatively quiet) unit ramp up and down, depending on load. Ours doesn’t run 100%, but it definitely doesn’t run full blast most of the time.
I wish I had this video (and the previous one from the main channel) last summer when I replaced my AC/Furnace (TX). We went with an inverter system and the sales-person grossly oversized both the furnace and AC. I asked about doing a heat pump instead of a furnace and the price was insane which didn't make sense to me because I knew that an AC is a heat pump running backwards. It was 110+ºF and I didn't want to argue, I just wanted my AC to work.
Moving from a single-stage to an infinitely variable (actually 1024 stage) system did reduce my electric consumption quite a bit.
I understood your points in the original video. I'm sorry people didn't follow you, that's on them. Keep up the good work.
It's so weird that American installers rip you off by charging so much more for a heat pump. Where I live nobody would ever buy an A/C only for their home.
Fun tidbit about bearings. I worked in power plants for years and think about it for a moment. Main bearings on generators are spinning 24/7 for months, even a year or more at a time. They last just fine. In fact, when starting/ stopping, we started special oil pumps called 'lift pumps' to help avoid metal-to-metal contact when starting/ stopping. So yeah, spinning for hours on end isn't a problem for a well designed mechanical system.
Believe me the residential units are not designed with industrial grade bearings …..
A pumped hydro-electric storage facility I have been to has a spare-bearing in stock; the expected life of the first bearing is 50 years; that runs-out in 2028.
They spin the thing virtually all the time to stabilize the grid, even when it is not pumping nor generating - i think they called that 'making bars' for some reason. [power-factor?, bar-charts?]
To spin it 'dry' [of water] they fill the chamber with compressed-air to drive water out the bottom of the 'bell'.
The total weight of the spinning unit is 150 Tons.
Bearings LAST!
You are making an incorrect connection here. The dynamics of bearings in a power plant have very little to do with the roller bearings employed in your furnace. The primary failure mode for these small light duty bearings is a failure of the shielding which allows lubricant to leave or debris to enter. They almost never fail through the stop start stop skidding dynamics of the rolling elements.
The implementation of new HVAC technology that allows the transfer of heat energy in-between multiple inside zones / apartments sounds rad.
It's not even that new! I have worked on many apartment buildings with water source heat pumps. They generally have an in unit heat pump, which rejects or absorbs heat from the water loop, then a chiller and a boiler keeps the loop around a design temp.
I see what you did there
Sadly as far as I know, no-one does house sized "variable flow with heat recovery" systems, which is why it was mentioned only in the context of apartment blocks.
The smallest system I've found so far has an outside unit that's about 1 cubic meter (around 3x3x3 feet) which wouldn't be acceptable to most home owners, and would be seriously over sized for anything but the largest homes. *8')
Dual Fuel makes a ton of sense in a ton of regions. Had one in my last home, and I plan to put one in my new home too.
All the efficiency of a heat pump for 300+ days of the year, and gas for the worst cold days and as an emergency fuel (if you know what you’re doing)
Here's an amplification for not oversizing your AC: I had an air conditioner that was grossly oversized that often had its condensate lines freeze. So during hot days, it was entirely possible you wouldn't get any cooling. The Nest thermostat I had was extremely frustrating to work with too.
You had an air flow problem or metering device/ref charge issue. Over-sizing causes short cycles not icing of the indoor coil.
I love experiencing how talented of a teacher you are; I get to learn cool new stuff and also watch you nerd out, it's the best
I am so happy you are doing this. I am in the same boat, I've boned up on hvac and have been doing major retrofitting and have revitalized my knowledge on current cutting edge in insulating, water and vapor management etc, and all the people I talked to, the hvac industry/installers are just not in the same ballpark when it comes to cutting edge according to many many contractors.
You are spot on in your comments, and I myself find myself defending myself from various extremely uninformed hvac people. We no longer live in an on and off full steam ahead hvac world.
When you're sipping power all day instead of guzzling tons of it two or three times an hour, efficiencies go up. It literally becomes a math problem easily solved.
Keep up your great entertaining and informative work
The only people I know who really understand HVACR theory: good building management engineers, data center engineers, and you.
Too bad they are facing hordes of bean counters, sellers and - worst of all - customers bamboozled by all sorts of nonsense.
Data center engineers out here still live in the overpowered push lane - pull lane mindset. And they definitely don't grasp the edge case intricacies of "non-condensing". 😂
Bruh my God
I didn't see balancer in there but I'll let it slide since no one knows we exist haha
@@tylerbalazic4592 Touché good sir!
I got a heat pump last year and have the same trouble explaining it to people. I was so happy for the polar blast because at least it would prove that I did not freeze. It did convince some, not all. BTW, I decided not to get heat strips because the the quoted price was very high. I could buy a lot of space heaters for that.
As a physicist, I approve this message of heat pumps with ">100% efficiency". I think thermodynamics/statistically mechanics is not most physicists strength which might explain why some bristle when people say ">100% efficiency" but you are correct; they can move more energy to than they take to run.
Right the temperature differential created by a heat pump cannot be exploited by a heat engine to run a perpetual motion machine. So no laws of physics (or thermodynamics) are being violated. There's still no free lunch. I realize you already know this, hopefully it will enlighten other readers (but probably just confuse them more)!
Townhomes that I've lived in typically have concrete walls in between the units to act as fire-breaks, which ups the insulative values anyway.
i love what you do, and i love how you do it. please never stop.
Your videos certainly helped my family make the decision to install a heat pump just two weeks ago. We have a 6-year-old gas furnace but a 20-year-old AC unit. I couldn't convince my wife to move to a heat pump 6 years ago when our furnace failed and I'm kind of glad of that now because heat pump tech has changed a lot in those 6 years. And there are financial incentives now that didn't exist then. My wife agreed that we wanted to replace the AC before it failed and so moving to a heat pump system with our gas furnace to supplement on colder days made lots of sense. There is one more benefit that wasn't news to me but was to my wife. Here's how she put it: the furnace would push lots of heat into the house at once while the heat pump trickles the heat into the house regularly and that is an outcome she likes better.
As a Sweden i would say that, yes, things have come along in six years, but not that much. They were really really really good at six years ago too. 20 years ago you could get a heat pump that worked down to -20C.
A side note: The first heat pump in Sweden for domestic home was installed in 1948. That is 76 years ago...
Liquified gas is measured by weight or expanded cubic meters (if it was allowed to boil). Propane is almost always measured by lbs in the US. The standard tank for a grill is 20lbs, though 10 and 40 lbs aren't hard to find, either. There are also 1lb bottles for camp stoves, lanterns and heaters. (Flame King produces the only DOT certified, refillable 1lb bottles and you can actually get them 100% filled at home because of their vent system). I absolutely love that I can get away with being a cheapskate on my portable kitchen.
Bulk propane delivered to homes is sold by the gallon.
I went all electric from oil. We have 2 heat pumps and are in the northeast US. We have 2 Bosch ids units, one with 15k one with 10k aux heat strips, 3 ton and 2 ton units. Our total heating cost is down, no more oil tank, spending close to the same money but our house is much more comfortable when heating and cooling. The pricing will go down now that these units are set correctly by Bosch. We keep wood for the fireplace, as we did with oil since it didn’t fire without electricity, and a couple space heaters but since this move, we haven’t used either. Good luck with anyone looking to convert. For us it was a huge benefit.
Also, we used two installers, both had taken all the Bosch classes, both set them up wrong and Bosch needed to come out and set them up right. The Bosch rep said many installers still don’t understand how these new units work and anyone should be comfortable calling them for help. Glad we did.
In terms of cold climate heat pumps the Bosch IDS is a relatively poor performer. But on the other hand it's relatively cheap and backed by Bosch. The IDS is actually made by Midea (who makes tons of heat pumps for tons of brands). A no-name like ACiQ might perform slightly better but if something goes wrong you'll be glad you got the established brand.
For old fashion steam heating, if there is a power outage, you can often run them using battery power if you wire into the controller. Many will run on 24V and use around 5 to 10 watts. I have a very one that I have used on battery during a power outage.
It's hard to explain physics and engineering principles to the general public. I commiserate ...
As an electrician, electricity is hard to explain to people at all. Sometimes. Actually most times lol
@@goosenotmaverick1156It's sometimes hard to explain electricity even to electricians. I have heard so much bullshit over the years from professionals with years or decades of experience.
@@0106johnny i swear up and down to people that we just move magic with (mostly) copper 😂
I once you get deep in the weeds on it, I start to get lost, no lie. So I don't doubt that one bit
Proof: there are many perpetual motion vids (It's impossible)
@@goosenotmaverick1156 So I should preface with: I'm certified in neither, but I've got a physics degree and a willingness to take things apart, and have taught myself / learned from friends who are certified over the years.
And at least in my experience, despite electricity being the more interesting and more likely to kill you if you fuck up, HVAC (Or, I should say, Thermodynamics) is harder to explain to people than electricity unless you're getting really into the weeds of induced voltages and shit no one wants to deal with. Something about the idea that heat is energy is heat just confuses the shit out of people. What do you mean my outdoor air conditioner is hot? That makes no sense, my AC is supposed to be cold!... Well, you see it's transferring the heat energy from your house outdoo... WITCHCRAFT!
Some of the best researched, most entertaining stuff on youtube.
People who are THAT worried about the 1% of the time the air source heat pump can't keep up should just look at a geothermal heat pump. They're kind of amazing and they DGAF about what the ambient temperature is, plus you can plumb them to run in-floor heat which is really nice if you have a finished basement or slab on grade. Around here (where it gets way below zero frequently) you can even get a second meter and discounted rates if you install one.
Water always strikes me as a good energy/power analogy. A "fewer words" analogy of the energy/runtime thing is: imagine two buckets of water, one with a large outlet valve and one with a small. How fast will each drain if left open? That's how fast they consume a unit of energy (water). If small one is open all the time and large one is just open and closed periodically, they still use the same energy if all that's needed is a certain amount of water on the output side. Just, one (slower) is a lot smoother at doing it.
The problem is at 1:30 when he says there is no difference in cost in regards to run time. This is true for heat pumps which use only one type of power, but not forced air gas furnaces that require grid power to run the blower in addition to the gas consumption.
Alec, another great series. You can lead a person to a heat pump, but you can't make them use it. This is excellent technology that everyone should be using as soon as possible. It's a no-brainer. Maybe that's the real problem here!!! As I always say, don't take my word for it. Do you own research from reputable sources. You are doing a great service to man kind. Don't give up on us yet. Lol.😊
Just went back and rewatched your LED Stoplights video because of "But Sometimes!" and I gotta say, the jacket really does work for you! Glad you kept keeping it!
I live in northern Minnesota and bought an XC95m 97.3% fully modulating 80,000 BTU furnace, and looking at the matching 2 ton XV20i heat pump. The furnace is fully modulating between 32,000 and 80,000 BTU and the heat pump would be 6,000 to 24,000 BTU (they do have a 3 ton option as well). The seller / installer was not familiar with fully modulating furnaces, as was the case with every local heating company, and initially installed it without the communicating thermostat. This made my fancy furnace a simple 2 stage, not even a 3 stage... I demanded they install the proper thermostat, that they then wired as 2 stage, again. I re wired it as communicating and setup the features myself, blowing the mind of their senior service tech. So happy with the added comfort level. During the cold months my furnace runs about 18 hours a day, mostly on low, never allowing the warmer / colder air to separate and make cold floors and feet. The short and long is my house is old and drafty, I'd love to fix it all but if I had that kind of $$$ I'd just buy a better house. The old 80,000 BTU 91% single stage could only maintain 64*F in -40* outside temps, hence it being so over sized. The new is still 80,000 BTU but the added efficiency means I can now maintain 70*F at -40* outdoor. One thing I learned during the process of figuring out how to make my house liveable ( single stage was sweat-freeze-sweat-freeze as it cycled ) was how much efficiency is lost during the startup process. To stop thermal shock killing the heat exchanger, they preheat the heat exchanger every time the furnace starts, and most of that heat is wasted. This means short cycling does in fact reduce the overall efficiency of the furnace. I had numbers, but that was back in 2020 and I don't remember the exacts.
I read somewhere that in Norway they often deliberately UNDERsize the heatpump to about 85% or less because it rarely gets cold enough to run, and the extra cost to fully size it never pays back over the life of the system since simply using extra supplementary heating for the few days a year it under performs is cheaper.
That is very logical. But that requires people to do something and use auxiliary heating in the rare situations.
Not something a lot of americans seem to be willing to do or able to comprehend.
@@rogerk6180 The main people that would be for spending more money would be the installers.
@@rogerk6180 when heat pumps were introduced all homes were heated with resistive heat, usually panel heaters, electric oil radiators, floor heating or a combination of these. (There’s no gas) so when heat pumps are deployed to a property, there are always plenty of additional heat sources available. Unsure about new builds but I suspect additional heat sources are so ingrained in people’s psyche that it’s just a given that you’d have a couple of resistive heaters sitting around.
@@TheShortStory some homes in nordics have/had oil heating. but anyway, yeah in nordics adding a heatpump is an addition generally.
in finland people have them installed and it's the first air cooling device they have as well.
@@lasskinn474 yes, some homes in the Nordics do but my reply was specifically about Norway, which the top-level comment referred to
As an HVAC professional in the commercial space, I appreciate your videos! One thing I will add is that the most efficient heat pumps typically come as ductless splits. More conventional package unit heat pumps or split system heat pumps are not as efficient, and typically don’t work as well in the colder climates below freezing. I just upgraded an HVAC system in my house and I knew from the beginning that I was going to get a heat pump, but I will say that I am disappointed with its efficiency below 25°. I’m very happy I chose a dual fuel unit with natural gas (I’m in Nashville, TN - so not all that cold).
I will also echo your comment about professionals not keeping up with technology. I had to really push the contractor I was using to get the dual fuel heat pump, and he did not believe the heat pump wood work below 40° or so. Most of these guys are good ole boys who do good work, but are not up to date with technology. That technology typically takes a couple decades to work into residential applications. Also, it is more complex to work on so be ready to look for a contractor a bit longer than you are used to, and get used to spending a little bit more on repairs.
Overall, I think everyone upgrading their HVAC system should have a heat pump in some capacity. Even if it isn’t the fanciest unit that can heat at all times, most people will save money with a heat pump 90% of the year.
Solution! We rename "heat pumps" to "reversing air conditioners"
I always thought "heat pump" made more sense... At least in my brain. We are pumping heat from the outdoors to the indoors, indoors to the outdoors, inside this refrigerator to the outside of the refrigerator, from the air outside the water heater into the water inside the tank, etc....
Ac 2.0
@@ClaytonDorrissome part of general public would understand "reverse air conditioners" easier and would be less prone to fearmongering rather than with shorter and more elegant "heat pump". It's simply because everyone knows what AC is and it doesn't need explaining, even a single teeny tiny sentence.
How about "bi-directional heat movers" ? :-)
@@ВалерийШадрин-л5г Interesting opinion, given my summer electric bill is $480/month to run a heat pump and my winter electirc bill is $90/month to run a not-heatpump aka, forced gas furnace with a $90 gas bill.....
This topic is so interesting to me that even nearly 2 hours of content about it holds my attention for the whole time. I would watch an hour long video explaining to people why turning up the thermostat doesn't make it warm up faster, it just either makes it too hot, or your hvac system is broken.
Not so with variable speed compressor heat pumps! They react to the temperature differential and can dial up the output, unlike most other heating and cooling units.
Also should note that in a system with "aux" heat, often the thermostat will call for aux heat if the temperature differential is over a certain amount. But, at least in common systems, that is a binary: if the difference between the temp and the thermostat is > 2 degrees, aux and main are both running (and it heats up faster); if it is less, then only main is running (it heats up slower, but is much less expensive).
It would be nice if thermostats had a "stat!" button or dial, meaning, "I want it this temperature as quickly as possible, no matter how much it costs", and then would only ever kick aux in if the temperature with main (or increase the rate if the temperature with current rate) was going in the wrong direction. Of course, then we'd need parental controls on the "stat!" button ...
Hey, I want to say thank you for this. I’m a mechanical engineer, probably around your age, and I remember learning about heat pumps in school and have touted them since, and that was over a decade ago; they’ve only gotten better since, which you mention.
I think this sort of message is super important to get out there and I agree with you on every point. Only comment I’d offer is maybe show a calculation or visual to show why energy and power are different, but that could just make sense to me because I already understand the topic.
The way you described VRF systems makes me think that a single family residential application would be using your own basement as a geothermal heat pump to cool the upper floors. That would be so cool to see in a multi-zone system in the future.
I've had the same idea and looked it up, apparently it wouldn't work because in like an hour the basement would be hotter than the outside.
@@3x3-x3x-oXo Exactly. Geothermal isn't really getting heat from underground, but using the huge thermal inertia of a large volume of dirt. If you could build the great pyramid of Giza next to your house and use it for that it would work the same, but I guess just drilling some holes in the ground and stuffing pipes on them is easier!
@@karellen00 They actually do take the heat from the ground.
The temperature, at least here in Sweden, increases with 2,5 degree C/100 meter down.
And the temperature at 15 meter is the same as the average temperature above ground at that place.
So if you have an average temperature at 6 degree C where you live, the temperature at 115 meter below the surface are around 8,5C.
Of course, this could vary a bit depending of geology but it is a good estimate to calculate your need.
@@Xanthopteryx Yes, but the heat from the ground is just the 2.5°C at 100 m depth, that alone wouldn't mean much. What you really use is the thermal inertia, you have so much amount of stuff that it would take longer than an year to get to temperature, so the ground stays at the average temperature. That's why you can both extract heat in winter and dump it in summer. To be fair this that I described is low enthalpy geothermal, there is high enthalpy geothermal too, that directly gets heat from the magma, but the places where it's available are only a few, and it's not the kind of thing you use to heat an house.
thanks for clearing that up, for some reason "running constantly" seems bad/inefficient /constantly using power. i dunno any numbers that was just my intuition. if i need to swap out my furnace or AC ill probably get a heat pump with aux heat strips.
Thank you for doing this.
Also, conveying that homeowners cant count on contractors to do load calcs, well, for free, and if they do the bad outcome is their fault.
BBQ tanks hold 20 pounds of propane, but the issue with propane, and why you need a big tank, and in a colder climate you need an even bigger tank (or some way to heat it), is vapor pressure. A BBQ tank won't be able to supply enough propane to run most appliances not because 20lb. isn't enough propane, but because propane stops vaporizing at -44F, and if you pull a lot of propane out of the small bottle rapidly, it will freeze up. The larger volume of the 400lb and 1000 lb. tanks have more thermal mass and surface area, which mitigates this. That's why you typically see one or two 400lb. tanks hooked to a 7000w backup generator that probably won't use more than a 1/10th of that in a power outage.
This is important. Propane as a source of heat only helps if you're rocking a 100lb tank or bigger because of vaporization. At that point you better have enough land. Who would do that in the suburbs?
I was actually aware of this problem (propane itself is a refrigerant!), but I was talking about storing smaller tanks indoors. Some might not be OK with that (understandably) but even then there are plenty of ways to fix that problem besides relying on the thermal mass of giant tanks.
@@TechnologyConnextras I used to have a tank heater blanket on a 400 lb tank which was meant to be used with a thermostat to keep the tank ready to go, but since I was off grid I would only power it when the generator was running to keep the pressure up. I've since switched to diesel because it's just easier to get the fuel up to the cabin but you could run everything you need in a house off propane if you wanted to.
@@TechnologyConnextras I still have issue with the recommendation of using propane over natural gas. It's like 3x as expensive and course needs to be filled unlike NG which is piped directly into your house. I still haven't heard a compelling argument to ditch NG in favor of heat pumps or electric heat.
@@rob21 unless you live somewhere that has absurdly expensive electricity and absurdly cheap natural gas, an efficient heat pump will produce the heat cheaper than gas unless outdoor temperatures are very low.
And he mentions the propane as being for emergency/worst case scenarios, not as a primary heat source. You can buy a couple grill tanks and keep them saved for the few days a year at most that they would be necessary. Plus with NG you have to pay a connection fee even if you don’t use any. I don’t know much about it because NG isn’t available here, but $25/month seems normal from comments I’ve seen here and just by ditching that cost you’ll save quite a bit of money by buying a couple propane tanks for to use on those extremely cold days where the heat pump isn’t enough.
lol I was listening to this in the background, was about to pull into a Home Depot, right as you mentioned Home Depot (note, listening in the background like a podcast, and did not comment while driving.)
These videos explain it to such a depth that only us nerds in the industry know it so I don't blame laymen for not knowing things people I work with still don't understand fully. It's not simple, I've been in the trade for 10 years and I'm still learning as I run into new niche pieces of equipment from over decades
Haha, you finally said at the end what I was thinking from the beginning of this video: "But sometimes...!"
FYI, unless your heating plant is an old steam boiler that lacks modern conservation and safety technology, your gas heating plant won't work during a power failure. I have a gas heating plant, and here's the order of events that takes place to make it turn on: First, a "demand for heat" is sent from the thermostat. What is a "demand for heat"? It's when the thermostat switches on the 24V circuit that operates the relays that turn the furnace on. And where does that 24V come from? Why, it comes from one of the circuit breakers in my house, via a transformer that steps it down from 120V to 24V. So, no electrical power means no demand for heat, which means the heating plant stays off. But assuming the electrical power is up and running, when the "demand for heat" is received, three more things happen: Since my heating plant is a hot water system, an electric circulator pump is switched on. At the same time, a small motor opens a chimney flue. Assuming the sensor in the flue sends back a signal to start the burner. This activates the safety valve for the gas, which, if the valve detects that the standing pilot is lit (it starts the gas flow, the pilot lights the gas and I start to get heat. My boiler isn't as sophisticated as it could be, so it the safety valve detects that the standing pilot is out, the action stops there, the flue remains open and the circulator pump continues pumping cold water through the system. 😝But the point is, no electricity, no heat, even with a gas heating plant. Modern forced air and steam heating plants make analogous use of electricity, with similar burner activation systems and, for forced air, electric blowers.
What happens if your heat pump breaks? Same thing as if your forced air, hot water or steam heating system breaks down, and I have no reason to believe that this is less likely than a heat pump breaking down. I've lived with all three types of heating systems, powered by both heating oil and natural gas, and all have left me out in the cold, so to speak, on multiple occasions.
Gas stoves: If you have a modern gas stove, chances are that your gas stove doesn't work if the electric power is out, either. Modern gas stoves, even basic models without whiz-bang features, use electric relays to turn the gas on. This is a safety feature that's supposed to eliminate asphyxiation and explosion risks if the electronic ignition can't work. The days of pilot-lit gas stoves are long gone.
One slight correction: gas _stoves_ in the US don't have safeties. While they won't automatically light in a power outage they can be lit with a match. Gas _ovens_ are as you describe. Almost all* have digital controls and electric gas valves.
*Somehow I ended up with an exception. This oddball oven has an intermittent pilot. When you turn the knob it mechanically opens the first valve and the spark unit lights the pilot. From that point it works like a traditional standing pilot system (with a thermal safety valve). Once the oven knob is turned back to OFF the pilot is turned off. If the intermittent pilot it lit by hand it can be started and used 100% without an electrical connection.
Technically true - but missing the reality and he addresses it at the very start 4:14
Backup power for a GAS system just needs to provide enough power to turn the fan. Which is 1/10 of the power to run a heat pump.
Personally (and true for our Host) I can pull enough power from my BEV car to run a gas furnace, a few lights, and a fridge. Enough to get through a winter power outage.