Tesla Model Y - The Only Tesla With A Heat Pump
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- Опубліковано 1 гру 2024
- How Heat Pumps Work - A Super Efficient Way To Heat Electric Cars
Here's How The Tesla Model Y Tripled Its Heating Efficiency
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The Tesla Model Y has a device you won't find in the other Teslas. This device is a heat pump, and it's a super efficient way of heating a cabin. Many electric cars use resistive heaters, as they cannot rely on the hot coolant from a combustion engine to heat the air for the occupants. This resistive heat draws energy from the battery, meaning cold weather range can be severely reduced for electric cars, unlike heating a gasoline power car. The Tesla Model Y has a clever trick to dramatically reduce the amount of energy needed to heat the cabin. Is the Tesla Model Y good in cold weather? Watch the video to learn all about how heat pumps work!
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**Important Note** This system (though not necessarily all heat pumps) is essentially reversible. With clever valving, you can flip where you're rejecting heat. Instead of heating the cabin, you cool the cabin by pulling heat from it and moving it outside (again, flipping around the section 3 diagram).
How does the expansion valve work? Is it just resistance or does it convert the pressure difference into a bit more energy?
Most heat pumps for residential or commercial do reverse: the heat pump has a reverse cycle to defrost the evaporator.
You should consider diesel engines. Modern diesel engines in passenger car take really long time to heat up the cabin, accessory heaters are often required.
ohh man how do you know all these info? I love cars but many stuff I don't understand, how did you do it to know every component of a car?
I do think the thing in the video sounds like a air conditioner but inside out
You can play this video in reverse and you'll hear Jason explaining how AC works
😂
Instructions unclear got my Tesla going backwards.
Except a heatpump is not a backwards AC. Every A/C is a heatpump.
Basically if you have an air to air heatpump, then you can call it an A/C. A lot of Aircoolers that people have in their house also have a heating mode.
No.
A satanic prayer to refrigerant.
Special thanks to Engineering Explained for the shout-out! Excellent video - very informative, very thorough, and yet very digestible! We might have to convince Sandy to channel some of your whiteboard skills!
"The second you get in the car you turn on the heat and you're already getting hot air. That's a beautiful thing."
It truly is beautiful. A person may almost shed a tear to the thought of instant warmth while on a cold winter day.
my 58 VW Bug had instant heat too. the aircooled motor provided heat rapidly
you could also cut open the batteries for instant warmth
As beautiful as a portable hairdryer ?
@@JG_UK what about the rest of your body
I always enjoy the feeling of a cold car slowly getting up to temperature
So in short, the Model Y uses an AC in reverse, which is better because it uses a little battery energy to use more energy from outside of the car instead of using all energy from the battery.
Coming soon: the nuclear core heater! Provides all the heat you want, or don't want, for a hundred years! Guaranteed not to fail and leave you freezing.
Brought to you by Vault-tec.
🤭
the only question I have is how quickly does the heat pump heat the cabin vs not having the heat pump? He mentioned using just the battery is a slow way to heat the cabin.
@@calebharris4127 Nissan Leafs at least have resistive elements in addition to the heatpump to accelerate heating and also assist on very cold days when the efficiency of the heat pump is too low to heat the cabin. However on normal days the heat pump will heat up the car very quickly. The heat comes right away. You don't have to wait for it warm up or anything like in an ICE vehicle.
@@calebharris4127 just as fast as your car's AC gets cold, after you first start it. Only a few seconds.
@@calebharris4127 well according to his number of efficiency at 3.4, vs resistive heating (numbers probably from another tesla) heat pump uses 1Kwh compared to the resistor using 3Kwh. 1*3.4=3.4 though, so the heat pump ideally would be about 13% faster in heating up the cabin after all the energy savings since in theory it would be providing 3.4Kwh worth of heat into the cabin
I have yet to see an EE episode that didn't expand my understanding of the topic at hand... And (almost always) my understanding of the universe as a whole.
You don't know how happy it is for me to hear this! Really appreciate you watching! There's so much neat stuff out there. :)
42. There you have it.
@@nielsonderbeke8507
The ANSWER is useless if we do not know the QUESTION! :-P
that is why he has 489 million views AND growing. I am also glad to see so many smart subscribers who appreciate smart info.
People in Antarctica: "It's negative 40 degrees where I live!" Is that Celsius of Fahrenheit? "Yes."
Kelvin
Plot twist: its neither, he was talking negative 40 Kelvin. Thats right its so cold in Antarctica that the world runs in reverse.
dsparke93. Not possible.
Zero Kelvin is absolute zero
@@Froggability Yeah its a joke. See where i said the world runs in reverse at below zero Kelvin? That should have been the giveaway.
@@Froggability r/whoooosh
It's basically A/C but with an uno reverse card
No, it's more like Challenge play in the Cones of Dunshire.
AC is just a heater designed to warm the outdoor.
Which is well-known as reverse-cycle air-conditioning - which most air-con units do these days.
nettles89 Ok Ben
@@andoletube In the US most air-con units are hardware configured to do just cooling. In Europe almost all air-cons you can buy today have the "INVERTER" split system technology, which is basically a few extra valves to switch low pressure and high pressure radiators, so the flow of heat reverses. According to official figures, at -15C outside temperature the units are still around 200% efficient, but at around -20C they switch on an integrated resistive heating element.
I've spent a considerable amount of time trying to understand how a heat pump works and finally "get" it now thanks to the way this engineering has been explained.
I think the evaporation and boiling of the refrigerant could be disregarded. I find it easier to understand without these processes. You take air, you compress it, it heats up, you cool it off (in the cabin), you take that air outside, you expand it, it cools down, you let it warm up again and repeat. I think the boiling and evaporating is requires/captures much more energy and that's why it's combined with this process.
@@mik13ST very interesting and fascinating. And it would do that in reverse during hot weather, correct? Or does tesla use some other method for AC?
@@yonmoore See the pinned comment by Jason.
@@mik13ST The phase change requires a LOT more energy than just relying on gas expansion/compression.
Ummm, if you would just google it, there are tons of articles and videos that explain it very well actually....
Heat pump = airconditioner connected backwards.
Conservator Wow you must have a doctorate degree.
air conditioner = Heat pump connected backwards.
Heat pump=-airconditioner
A heat pump, pumps heat from a source to a sink. That’s the most generic definition you can find.
@@tim8505 touche
ICE cars driving in front kindly provide a warm exhaust for improving the heat pump efficiency :)
Don't forget to mount light sails on the back of your car when somebody is tailing you at night.
I have a story about this scenario you're describing.
Many years ago, I was blasting on the German Autobahn in a simle VW Golf TDI at its electronically limited top speed of 180 km/h. A friend of mine drove in front of me in a Porsche 911 Turbo and started to slow down because he was distracted. Because it took me FOREVER to get to my top speed, I didn't want to lift off except when really necessary, so me and my Golf came closer and closer to the Porsche's back. Just as I was thinking that I was getting too close, my friend noticed his entire rear view mirror was filled with a VW-logo and mashed the accelerator. He sped off into the distance and I felt a whoosh of hot air enter the cabin through my ventilation system. That's how much heat is wasted when you floor it in an ICE car...
Bert Troubleyn I’ve always wanted to drive the autobahn
This is simply not true.. heatpumps in electric cars use the cooling circuit of the electronics to exchange heat to cool/heat the inside. Unless heat needs to be discarded, there is no exchange with the outside air.
@@jimmywise4538 jimmy not-so-wise
It's actually quite huge. Norway is a massive market for Tesla, and it's quite cold most year round, so this is a massive benefit for us
Your videos are straight to the point. As simple yet detailed as possible. One day they'll use your videos in univ courses I'm sure.
Or maybe one day universities will be superseded by Jason. He should consider issuing certificates to those who have watched say 3 years worth of videos. You'll land your dream job in no time, guaranteed!
Seems like with resistive heating, the COP is a constant 1.0 and with the heat pump, the COP is variable from 1.0 to 3.0 and that the COP will be above 1.0 most of the time. Thats where the Model Y’s batteries will gain the increased coefficient drag and possible weight gain compared to the Model 3. Just like reducing weight on a car, saving energy is regaining small percentages at scale. Very informative and great job explaining this topic!!
I always thought air conditioning was magic .....but you explained it and simplified it so much I actually understand it . You sir are amazing thank you
and now you can also understand how you make liquid nitrogen, or liquid oxygen (squeeze it, which heats it up, then cool it while squeezed, then unsqueeze it!)
Magic is the best answer for explaining how anything works. It becomes less effective the more you know.
Excellent topic, and good explanation!
Heat pumps are often described as “ an air conditioner in reverse,” but a better description is that heat pumps are essentially *the same as air conditioners* , but just swapping indoors for outdoors, and outdoors for indoors. If I were doing this video, I personally would have taken that approach: Describe how an air conditioner works, and then say that a heat pump is essentially identical but with indoors and outdoors are reversed.
The main reason people find that hard to understand is that they don’t spend time near an air-conditioner condenser (the outdoor-unit) so the don’t realize just how hot they become!
The heat pump in our Prius Prime works great, BTW. Having such a tiny battery, a resistive heater would kill its range. That heat pump is described as “gas-injected,” but I can’t recall what exact that entails.
I’m not sure about Nissan’s claim of the first heat pump in a production vehicle, since GM’s EV1 has one too. Perhaps they’re arguing that the EV1 never hit full volume production.
Jason, great video. When I heard the Model Y was going to have a heat pump I immediately wanted to know how it worked. I figured out how the heat pump worked but couldn't understand where the "free" energy was coming from and why it was more efficient - outside! Great job at taking the next step and answering questions many of us had before we even asked them.
Yes a heat pump it's a machine that transfer's temperature, doesn't convert eletric energy in temperature. But doesn't "compress that energy" 7:16 :). Seriously i like your channel! Well done! Regards from Portugal.
*The Only Tesla With A Heat Pump*
But Y?
lol
ComplexitY?
Yes.
Simple... but 2 reasons.... 1. Tesla has now learned how to make the drive train, so they dont have to spend all the production money on that. 2. You will increase range, simply beacause you are not using all the battery power to heat the car :)
Y not?
It seems like a refrigerator where the external element on the fridge gets hot is one side (the inside in this case, of the car) and what would be the inside of the fridge, is like the exterior panel the refrigerant flows through in this case. I can confirm that refrigerators stop working, and indeed you are instructed in the notes that come with it, NOT to locate them in COLD places, ie where the temp drops below freezing. It’s because of the limitations of this system that you explained. Patently, the refrigerant is a critical thing, but the ‘failure’ for my domestic fridge was about -5 deg C at worst, inside a brick-built garage, so very little below freezing. It took me a while to realise there was nothing wrong with the fridge, but I would have to heat up the garage (!) to make it chill food properly! I ended up burying food stuffs in a plastic tub in the snow that winter, and I dumped/recycled a perfectly good fridge it seems!
Very interesting! The BMW i8 uses a heater element, when it's in electric mode, to heat a portion of the engine coolant circuit that's going to the cabin. And, just the opposite of Tesla, it uses the AC compressor to chill a manifold going through the battery pack, rather than using coolant to keep the batteries temperature controlled.
My ioniq also has a heat pump, the system has 2 condensers and 2 evaporators.
The cabin airstream has one of both, one for cooling one for heating.
However in front of the radiator is just a condenser, the second evaporator is at the hottest point of the coolant system, just before the radiator.
So the heat pump does draw heat from the driveline before "warming" the coolant in the radiator.
A PTC is also fitted for window defrosting.
The drawback you mentioned with the lower outside temp is easily solved by A) increasing the compressor compression ratio or B) changing to different gas. Also after some time when the outside circle gets frosted you can start heating it up with the then increased heat from the motors and electronics.
You can also just run the system in reverse (AC mode) for a bit to defrost. Home heat pump system do this on a regular basis to keep the outside exchanger free of frost.
If you live in the southern U.S. (or anywhere with mild winters), there is a decent chance your home "air conditioner" is actually a heat pump. Their ability to extract heat from the air drops off significantly with temperatures below 40F, so these systems will have back-up resistor-style electric heating coils.
It's -40C where I live
I knew it! Wishing many heated blankets upon you.
@@EngineeringExplained *spoken with heavy Russian accent* Do you know what we call -40*C? A warm summer day.
It’s (+)40 C where I live
Yep... me too (Alaska). Be sure to share those blankets with me. The Nissan LEAF I have has a resistive heater, and I need it as a heat pump just is not up to the task.
You shouldn't buy an electric car where you live, at least not in the present time
Essentially it's most effective (3/4 COP) at roughly 22c and becomes pointless at roughly -8c . Thanks a lot. I live in Canada and thought this would be necessary in our climate.
I have this in my house..its an amazing tech best electric heat by far
Yes I have it too and was build in 1992
I have it in my car, so far it's pretty good. It's a Tesla.
@@nolanhairr nice. Someone should make a video about how it works
I’d be willing to be that most houses use heat pumps nowadays. Resistive heat only works in a couple of scenarios
Yeah I have it too and my neighbors have had one over 15 years now (still works though needed a refill). My father has had a geothermal heat pump from about 1992 (changed it to a new one at 2014).
There are many videos about heat pumps. Just search something like: "How a heat pump works". But I think that it is well explained in this video as well.
Thanks for the lecture on heat pump. I have a Hyundai Kona EV which is using a heat pump from the get go. Now I have a better understanding of how it works. It bugs the heck out of me when I don't understand how a piece of technology works.
When i heard that the model Y is going to have a heat pump i thought "wait, other teslas don't have a heat pump!? Wtf?" Seriously, I don't know of any electric car that doesn't get a heat pump at least as an option. I hope the model 3 will get the heat pump too... Currently im not in the market for a new car, but the model 3 has been a favourite for some time now.
I thought the same thing. However, Teslas are also the most efficient cars, so they probably aren't worse than other cars that have heat pumps, in cold weather. I'm sure there are stats out there to answer this.
Because Tesla's heat pump is unlike any other. It takes time to innovate and manufacture. No mention in this video of the most important part - the Octovalve (see Munro).
My Bolt EV doesn't come with one... have to say, it would be nice to have! Heater takes ~7kW to run, vs the A/C only ~1kW. I honestly don't bother suffering the heat in the summer like I tolerate not running the heater in the winter, because the A/C has such a high COP compared to the heater.
@@waynerussell6401 "like no other" lmao what are you even saying? Tesla is not some alien company making non existent tech. They just needed time to copy others (as not to pay somebody else for their pump) and make their won.
4 months later: Model 3’s are getting the heat pumps now too 😁
Living in the FLA panhandle we need both AC/Heat and use a heat pump. My experience has been when the temp drops below freezing, the pumps efficiency drops quite a bit and we go to the resistive part of the system.
I’m sure Jaguar I-PACE has the heat pump concept. Basically an AC system that work in reverse. Doesn’t look fun to diagnose!
Canadian checking in, leafs are around, those kia souls though saw them every day in the winter. did see a model x on a flat bed with no visable damage, and we had a bad winter this year. the most suprizing car i did see each and every day was a subaru domingo.
Learning thermodynamics is my mech class. Cool to see it in use
Air based COP for headlamps noticeably starts to drop off below 5C plus condenser ice up more. To reduce icing the heatpumps have to cycle in revise so while doing this for few minutes no heating. So great from 5-20c ok for 0-5c and below either unit needs oversizing to stop output reduction from reduced COP.
Finally. Electric cars cheaper than the Model 3 have had heat pumps for a while already. Tesla should update their entire model range to include heat pumps.
Kepe Yeah I'm super surprised to find out this is the first. It's such a basic thing I assumed they've always had them
The M3 is overrated and comes with a smaller battery while less EPA range considering cheaper options.
Having heat coming out of the same vents as your ac does not mean it has a heat pump
I think even at the time you posted this comment, the model 3 already had a heat pump. IIRC they have all had them since 2021
Chrysler tried in the mid-90s with their TEVan to make a heat pump (reversible heat pump for the pedants) using a regular refrigerant-to-air heat exchanger on the front of the vehicle and found that it would frost and freeze (just like reversible home units) below about 50F outside air (depending on other air conditions). This design overcomes that problem by using a refrigerant-to-brine (glycol/water mix) heat exchanger, enabling usage all the way down to 0F outside air temperature.
That brine loop, however, still depends on heat exchange to the air using the single brine-to-air radiator or other heat sources in the vehicle such as the traction motor/electronics and battery. Once the demand in the cabin for heat exceeds the vehicle heat generation, the brine loop temperature could drop below freezing and start allowing the radiator to collect frost and eventually ice.
Tesla can mitigate this to some extent by using an actuator to close off the radiator intake from the outside airflow, preventing exposure of the radiator to the freeze potential of the humidity of fresh air.
People always talk about heat pumps in cars as if they were completely separate systems. I think this is also confusing in the video, pointing at the "heat pump" of the Model Y whereas it is actually the standard A/C compressor.
To my knowledge there is just some extra piping added to the A/C system to let it run in reverse (swap evaporator/condenser), which enables it to function as a heat pump.
Yep, didn't intentially mean to leave out that it's reversible and can be used for A/C. But that doesn't mean that cars with A/C have a heat pump for their cabin, as they do not. It's not just a valve and dust off the hands haha.
Yes, cost of the added parts will have to be weighed against the range gained by the heat pump function. But I think without already having the A/C compressor in the car for passenger/battery cooling its part cost could not be justified by the higher COP for cabin heating itself.
Thank you for your great content by the way!
@@thedeerish If you are driving longer range and considering heat loss in Tesla's, it would certainly be worth it. Heating itself from resistive is not a small amount and the energy used can be close to what is used to maintain vehicles speed between 60 and 80 depending on road. The extra weight is negligible. Tesla omitting a reversible heat pump is simply them being cheap like apple relying on fanboys to hype up everything. Considering the cost of Tesla's, it should of been easily implemented.
To me it would make sense to run the cooling of the battery packs in series with the heat pump system. At least then the heat pump can get to work straight away with heating the cabin then the resistive heat from the batteries can take over when efficient to do so.
In colder climbs it absolutely makes sense to utilise as much of the waste heat as possible produced by the vehicle.
"ICE vehicles are so inefficient that it takes very short time to heat the coolant"
Tell that to my 1.9TDI on a -15C morning
world's most indestructible engine
@@PaulL42654 Until you neglect the timing belt.
...or my OM617. According to the owner's manual, one is to run the vehicle "not at an idle, not at a standstill" until reaching operating temperature. You "trot-to-hot" it like you're warming up Barbaro for a derby.
@@PaulL42654 or the cummins 5.9 (6bt) or toyota 1hd diesel......
Does not apply to diesels LOL
The Nissan LEAF does break down the power draw from both the compressor and PTC heater individually on the can bus. As such, the leafspy app shows that at low temperatures it uses resistive heat to supplement the heat pump and you can see the exact number of watts being pulled from both.
*Engineers:* we made a mistake sir and installed the AC backwards.
*Elon:* how fast can you fix it?
nonsense
@@alanmay7929 Im pretty sure this is EXACTLY how it happened.
It’s a technology that’s been around for a while. All it takes is a simple 3 way solenoid valve to reverse the flows. Definitely not an accident
Due to efficiency and strict energy regulations, heat pumps are becoming more common and are now found in clothes dryers, home heating (ductless mini splits), and water heaters.
Some heat pumps reach COP 1 at - 25 degrees celcius, this is dependent on what gas you use, some gases have better boiling and liquid points than others
Someone here knows their HVAC.
Some even use a very small amount of CO2 as the active gas.
Not just Antarctica but Wyoming, the Dakotas, Montana, Colorado, Utah, Nebraska, and I'm sure a handful more regions in the states that enjoy a balmy -20 c most of the winter. Not to mention 90% of Canada is cold as hell in the winter. For me this begs the question how useful electric cars will become in these regions because of all the battery and heat problems that exist living at those temperatures. But glad to hear if you live in a more mild climate your heater is more efficient.
Sick spoiler art my dude! XD
Heat pumps are used on houses in reversible fashion all the time. Old concept- newer application. Could you not just run AC backwards? Condensers get hot & evaporators get cold. The lines are skinny going from the compressor to the condenser. And they're big boned to allow expansion from the receiver/drier to the evaporator. This would make reversibility less efficient on one side or the other if you made the diameter the same going and coming to the compressor.
I think you could use the friction from that spoiler to heat the car....
I had a house with a heat pump, which worked well until it got real cold (Chicago) at which time I had the option of a resistive heater for the heat pump air or baseboard heaters. I have to admit that once it got that cold, the baseboard heaters came on the rest of the winter, which are much more kind to your skin drying anyway. I guess it would be like using your heated seats and steering wheel.
Well explained, thanks! One question: if the heat pump also works in summer for cooling (is that confirmed for the Model Y?), is the classic AC still needed? Or do they work simultaneously then?
Heat pumps use a reversing valve that switches the path of the Freon
Yes, a reversing valve is used to do that, in addition to defrosting the... Uhh, external cooling coils. I guess it all depends on how the terminology goes.
These things will still need a resistive heater. I don't see how they could possibly keep up at temperatures below 10 Fahrenheit. Residential heat pumps lose their chooch around those temperatures. So, in Canada or any northern state, that is every morning for 2 months out of the year.
@@paulstandaert5709 Likely not, Tesla has used some inverter waveform to the drive motor to dump some electricity to heat in the motor and their coolant loop via the octo valve is able to scavenge that heat. The real magic is the valving that enables heat to be moved into or out of key equipment as needed. The drive computer is now part of the cabin heating via the heat pump as an example. If you were really cold they could mine some bitcoin and let the heat pump move that heat into the cabin so you were warm while you shopped online with your newly minted btc (I made this bs up for fun). This avoids the added weight of another heater component. The drive motor is a heater if you feed it a waveform that is not synchronous with the motor rotation. It is quite easy to mix in some pulses that are not mechanically followable. As you may imagine there are many sources of modest heat that are used to help the batteries and the human performance.
Heat pump is for heating and cooling
Thanks for running through this.
So the heat pump is making the EV act more like a gas car in that it’s getting the heat from outside that which can move the vehicle. Outside air (EV) or waist heat (ICE) vs needing to use energy that can be used for motion.
Helps me understand the benefits anyway. I know it’s adding another source vs taking advantage of an inefficiently.
Newer mini splits can heat down to -24F MRCOOL ( COP better than one )
The main reason for using the term coefficient of performance (COP) is to differentiate it from efficiency. As you pointed out the heat pump is not over 100% efficient, it's just doing something different. I think the most practical type of efficiency is exergy efficiency. In thermodynamics energy is a hard term to deal with because most of the energy is in the temperature itself and cannot be accessed. We cannot take the energy directly out of hot air, this would decrease entropy and violate the second law of thermodynamics. To describe how much energy we need to put into a system to move heat around, we use the term exergy. Exergy is also used to describe the maximum energy we can get out of a heat engine.
The exergy efficiency of heat pumps is calculated by dividing the real COP by the Ideal COP. The Ideal COP can be calculated using the Carnot cycle which is an idealized heat pump with the highest possible COP.
COPcarnot = T_hot / ( T_hot - T_cold ) (Must use absolute temperatures)
The COP for the Carnot cycle is dependent on the temperature difference between the two sides. The Carnot COP is always above 1 no matter how great the temperature difference, but it's not practical to expect a real heat pump to be able to operate at really large temperature differences unless built for it. If the temperature difference is large enough that COP drops pretty low, then you might was well use a resistive heater.
To give an example of just how good the performance of a heat pump could possible be I gave the following example
Freezing outside = 273 K
= 0 C = 32 F
Comfortable temperature = 295 K = 21 C = 70 F
COPcarnot = 295 / (295 - 273) = 13.4
A COP = 13.4 is the highest possible for those conditions.
Notes.
Processes that are 100% exergy efficient are often described as reversible. This is because the process does not increase entropy. Since entropy cannot be decreased (second law), any system that increases entropy is not reversible.
You may come across another term called Carnot efficiency which is energy efficiency, and defined as n = net work done / heat absorbed by heat engine.
This is used to describe the efficiency of heat engines and thus will have higher efficiency when the temperature differences are larger.
When its cold outside, it might be a good idea for the evaporator to draw heat from the coolant.
Yes
It might do that above minus 20C, below that it's trying to keep the battery warm enough to do regen braking.
Bypass valve for the evaporator or discharge of the compressor will increase the heat inside the car. Increase temp and pressures on the low pressure side of the system increases temperature. Works exactly same as ac system.
11:38 "Still, all of it is very COOL" 🤣
Depends on the Heat pump technology and what kind of heat pump they used, but if it's topical then around -5 you are at COP 1-1.5. Everything higher will go up to Nominal COP 3. There are some commercial Heatpumps with Nominal COP around 4.8 and seasonal efficiency around 7.
Early! Great vid so far!
Thanks for joining so early!
How do they prevent water moisture from forming ice on the outside radiator in colder climate? Once ice form, the whole system break down.
@@BernardWei Someone else in the comments said that the Nissan heat-pump does use resistive heating to melt ice and start the heating faster. I assume the Tesla does the same.
There is some beauty in the fact that, long after the combustion engine is gone someday, cars will still rely on the principle of compression and expansion of gases to perform useful work :)
Pause at 10:36 for "Walk like an Egyptian" I wish I could post my screenshot.
Only us gen x'ers will get that...
12:06 will work as well :)
Hi Jason - nice review. Two comments: 1) The key to vapor compression refrigeration or heat pumps is the latent heat absorbed or rejected by the refrigerant during the phase change. The condenser rejects heat absorbed by the evaporator and the energy from the compressor. A lot of heat is transferred by the cabin condenser even thought the refrigerant temperature and pressure doesn't change much. 2) The 1996 GM EV1 had a heat pump. It was a reversing system, much like residential systems. The EV1 also had a PTC resistance heater for cold ambient temps. The Tesla system is not a reversing system. Inside the HVAC module the located in the instrument panel assembly is a dedicated evaporator for cooling and a dedicated cabin condenser for heating. The system switches between these heat exchangers and the Liquid Cooled Condenser (cooling mode) and Chiller (heating mode) in the frunk. This system can also operate in a "lossy" mode where it runs compressed hot refrigerant into the cabin heat exchangers. The system is very novel, especially considering the integration of battery, motor, and inverter cooling and the use of the battery pack as thermal storage for the heating system. It also does not have a traditional front end air condenser, it only has a coolant radiator to reject heat from the powertrain and the Liquid Cooled Condenser. The coolant flow around the system is managed by the Octovalve. Tesla's patent application for this system is public. Search Patent Application 20190070924.
Keep up the cool work!
When you mentioned the Model Y, I thought you are going to talk about the 'super bottle'. This seems to bring a lot of advantages in terms of efficiency.
Now they call it Octo Valve.
Not really. All the advances are from the heat pump. "Superbottle" is just the way Tesla chose to implement coolant routing around the car when implementing the heat pump. By itself it has zero impact on efficiency.
@@aigarius Is the Model Y heat pump fundamentally different from other heat pumps? I remember a few videos highlighting the efficiency of the 'Superbottle' or the coolant routing as you point out as the innovation in the Model Y.
I'm an HVAC technician, and I agree with what you stated, and I'm glad you spoke about diminishing performance in cold weather. Heat pumps are extremely efficient when it is around 40-50 degrees outside. But when temperatures drop below freezing, they start to have problems, and from what I've seen, below 10-20 they become useless. Between frost build up, and the temperature differential between the coil and outside, it may be doing something, but you won't be comfortable. For houses, we recommend everyone north of MD have a form of backup heat. Heat pumps are fantastic and I would never recommend against getting one for a new system, they efficiency in early spring late fall of 40-50 degree is incredible, but you need a back up to stop you from freezing during a harsh winter. I'm not sure how that that translates to a small moving car, but that's my 2 cents. Great video!
Thanks for sharing your insight!
With the exception being the current generation of high efficiency inverter heatpumps, they are heating in negative temps (not just minisplits). Though the mini splits and vrf units are leading the way, mitsubishi hyperheat provides full capacity to -5F and 80% at -15F. But yes, you are absolutely correct that conventional heatpumps that most people have at home start to drop off below 47F.
Can we get an episode on how much power the ford Godzilla V8 can make with minimum mods
Yea, and put racing tires on it and race it against a racing Tesla with racing tires or just tell us how long it takes the Godzilla to pass the Tesla and how fast they’re going at that point. Thanks for the great video!
Is that the big 7.3L engine? Seems neat!
Engineering Explained yuuuup
shody ryon you mean a supercharger and a mustang
Engineering Explained Hennessy made 775 hrspers with just a supercharger
can i challenge your calculations ? if the heatpump is designed properly it should have suction cooled windings (gas leaving evaporator cools compressor electric motor windings) so the amount of energy used to drive the motor (total KW input) should be added to the heat output calculation , of course this is a deficit in cooling mode but , quite often we find it heatpumps the heating output is far better than the cooling output , example a 2.5kw mitsubishi heat pump (which works down to -15degc) does 2.5 kw in cool and 3.5 kw in heat , of course this all depends on if it has suction cooled windings . ironically the worst temp for heatpumps in heating is between 0 and 2 degc as the free moisture tends to form ice on the evaporator , under 0 degc all the moisture is sequestered as a solid (ice). love your work jason
I’m just gonna act like I know what he’s talking about
Basically point of window unit air conditioner so that it cools the outside and it will warm your house more than a space heater that draws the same amount of power same idea but in a car.
Excellent description. This is essentially how the geothermal system in my house works as well, except it uses the ground for a heat source (heating mode) and heat sink (cooling mode) instead of air. I've never really thought about how a heat pump can be 300-400% efficient until I saw this video - great job as usual EE.
“It’s -40 c where you live” you didn’t need the c there sir
gotta make sure it isn't k!
FYI some small car diesel engines have gas/water heat exchangers on the exhaust, so that they can heat up the coolant faster (or if it's really cold outside, heat up at all :D )
I live in 30°c I need freezer more
Heat pump also is AC
I have a small economy electric car by GM. They have chosen a heat pump system for these exact reasons and to keep energy consumption down since it is a small battery (20kwh) however under -15•C really puts a toll on heating performance. Energy consumption can easily go up to 6-7 kWh without even driving when -20•C hits. I live in Québec so that happens relatively often in winter. I have chosen to get a separate fuel heater adjacent to the heat pump so I can turn off all electrical heating during winter and switch to using only fuel heating which reduced my energy consumption to basically almost zero.
I usually only consume 30l of fuel per winter and it’s only during really cold days. So basically one tank of gas per year. I used to drive 100km per day so it’s was a bargain.
I thought Tesla’s just caught on fire to stay warm
The heat pump that I worked on have reversing valves, that way your condenser turns into an evaporator and your evaporator the condenser when is cold outside, the suction turns into the discharge line and the liquid line stays the same but with a reverse flow. During the cooling cycle the reversing valve reverses and the evaporator and the condenser work like a regular air conditioner and cools the house. Also there is a defrost cycle to melt the ice if it gets to cold, and some heat pumps have electric heat as a back up and to heat the air during the defrost cycle. I am pretty sure some people will get confused with all this information. Great video.
Heat pumps have become very common in houses here in Norway, since about 20 years ago. It's way more efficient in heating up the home or living room than oil burners or electric panel heaters. And in the summer, most of them can be used as AC.
Same in the Netherlands. We are trying to to get rid of natural gas (to reduce shallow earthquakes and sinking of the northern part of the country) but we never heated homes with electric heaters so our electricity grid would not be able to cope with that. The extra factor of 3 offered by heat-pumps, together with accelerated upgrading of the grid, is what makes it possible.
I am AC guy. Heat pump is great in California and Florida. Not so good up north when outside temperatures drop to 0 F. If is frozen outside 32° F and below heatpump becomes inefficient and it will not heat the cabin. Prob they have a backup heat just like a air conditioning unit
You should mention he type of ac and refrigerant as well.
... Iove that little spoiler on the internal combustion car outline. Just.... a nice random touch to liven up that white-board. Awesome.
Every time you post a video, it’s answering a question I’ve been asking myself and my teaching instructors ( but they can’t give me a concrete answer ) so thanks for that😁👌🏼ps: I’m a car mechanic in Germany
Modern heat pumps have COP of over 1 at -30 degress C. We have a heat pump at our cottage, and sometimes during the winter it goes below -30 C for a few days, but it's still more efficient to use the heat pump than it is to use electric radiators. COP at low temps is quite dependent on the refrigerant used. Our heat pump saves a lot of electricity in the winter, plus in the summer it functions as an air conditioner. The evaporator frosting issue is solved by reversing the heat pump's action for a short while, pumping some heat from inside to the evaporator to melt the ice to keep the COP as high as possible, and thus lowering the heat pump's energy consumption. It's all automatic.
In ships the AC gas gets condensed by a water to gas heat exchanger but the temperature of the water can variate so much
between places they have mechanical self regulating water valves.
They control the amount of sea water going to the condensor. The High pressure freon lines from the evaporator are connected to these valves. They put a pressure on a diapragm wich alows a bit of sea water passing the valve via a pilot line, which in his turn puts pressure on a larger diaphragm which opens the large sea water valve. It's cool
At the end of the condenser cycle, it is a high pressure, medium temperature liquid (it rejects much of the heat if it is working correctly). It is no longer high temperature. You also neglected to mention that a heat pumps difference to an air conditioner is the reversing valve(s) which can change the role of the evaporator(s), and condenser(s).
My Kona EV has both a condenser and evaporator in the HVAC air path. I believe this is to emulate the dehumidifying function in an ICE where the AC is used in combination with the heater core. It’s very fast; from cold I can have a clear windshield in 30 seconds. I also mentioned elsewhere that I see orange HV wires going to that area, indicating the likely presence of a supplemental PTC for very cold climates.
This is a great explanation, my company builds for John Deere a facility and we use heat pumps combined with geothermal wells to heat up the building during winter and cooling it during summer, I think my next step will be combining it with solar cells (heating water) and solar power (electrical) to reduce the dependency on the grid, was surprised that the good old John Deere Green is considering such technologies!
My old chevy had a heat pump in place of the ac. I bought that thing 20 years ago. Basically it's an ac unit with a reversing valve to make it go backwards so it sends heat into the cab rather than cold. The outside unit will then be cool rather than warm like it would be when cooling. Simple and works great!
I have a Prius Prime (plug in hybrid), and the heat pump works well. Last winter I drove to work and back in a snowstorm. I had the defroster blasting on high the whole time to keep snow from building up on the windshield, and at 17 degrees F outside it was able to get the interior up to 85F on my 30 minute drive home. Of course using so much heat just about cut my range in half.
In my car the heat pump can work down to around 12 degrees F, but it is clearly much less efficient at that temperature than in milder weather.
It's interesting to observe the behavior of the car when it's in Hybrid Vehicle (HV) mode, getting all of its energy from the gas engine. On a very cold day if the heat is on, it will actually run the engine more often than it normally would, to keep the coolant hot enough to heat the cabin. That must result in slightly lower efficiency, but it's hard to measure it accurately. So for a normal gasoline car it's true that using the heat doesn't impact efficiency, but hybrids are so efficient that there isn't always enough heat leftover to heat the cabin. They do that by using a smaller engine than a regular car (a whopping 95 HP!) and turning off the engine when it's not needed. They make up for the small engine by having electric motors to provide a boost when more acceleration is needed (the total power output is around 121 HP), and by reducing aerodynamic drag so less power is needed in the first place.
Well explained. Another downside in an e.v. might be the weight and space that a heat pump takes up - which might aswell be used for more batteries.
Its a bread box - watch the video.
COP of 3 to 4 from the heat pump system would only be possible in moderate ambient temperature (50~60 F).
In freezing condition, COP of heat pump would be around 2.
As the ambient temperature gets close to refrigerant's saturation temperature at 0 psig, the COP would go toward to 1.
The Model 3 has the same heat pump. Your explanations are good, but I prefer those of John Kelly on WeberAuto which are more complete and accurate. He explains how 16 sources of heat are used and how works the octovalve. The heat pump circuit of Tesla is a jewel of technology !
In this case for the heat pump don’t you also have to factor in the heat produced by the motors, etc vs just ambient air temp as Tesla uses the heat pump for more than just heating the car interior. The Octo valve combined with the heat pump moves both heat and cooling around the car as and where it’s needed.
That's intense.. phenomenal seeing this technology advancing so much
I can confirm coefficient is 1 at -20C. Just passed a couple of days at that temperature in Montreal and my heating system was just. Totally useless basically couldn’t even start the system. Now it’s back to -11/15 and it’s back to normal.
In Norway it is quite common to use the same kind of system for heating houses. Although as you said in the clip it becomes practically inefficient at -20, most of these systems will close down and revert to electrical heating at -15 because of the wear it will put on the compressor.
They could also close the air intake for the radiator (improving aerodynamic) and thus using the evaporator side of the heat pump to cool down the radiator when it is operating. It can improve aerodynamics and also COP from heat pump.
It does get -20 oC here often. I will not be typing -40 for weeks but -20 we get. At that point it would be like any PTC EV and 40%+ reduction in range. Above -20 oC it will help and therefore makes sense to implement to us. Would be interesting to see typical heat pump efficiency vs temp plots/tables.
@11:07 FYR,
CoP for r134a > 1 at 0degC but is almost ineffective or has diminishing return at < -10 degC. Also r134a has a high Global Warm Potential (GWP) is 1430 (very bad for atmosphere). R134a was the fluid of choice in earlier model S/X, could be the current production ones too, not sure.
CoP for r1234yf (fluid used in Tesla M3 and MY) is similar to r134a but has a much lower GWP < 1 (acceptable from a Green house gas impact perspective). Tesla uses this in the MY heat pump, however they are able to put more heat into the fluid by running the heat pump's electric motor a little lossy to generate heat, which then is transferred to the r1234yf fluid, as a result keeping the CoP > 1 at ambient < -10 degC maybe till -20 degC. This was heat pump was designed by Tesla in collaboration with Denso.
CoP for r744a (CO2) is > 2 at -20 degC and > 3 at -15degC. Which is better than r1234yf and r134a especially in heat pump and performs similar in AC mode. R744a however operates at higher pressure (~100 bar) so the pipes and other related parts have to be redesigned and the supply base is limited. Daimler is the only one in production with one of their S class. Also GWP < 1, and not flammable unlike r1234yf, r134a.
5:23 *At atmospheric pressure. At a pressure of about 9 bars (130 psi) the boiling point of R134a increases to about 30 Degree Celsius (86 F).
Small correction. The temperature in the condenser doesn't change much, but it still rejects a ton of heat, it's just coming from the condensation process.
When you boil water, it's not getting any hotter no matter how much heat you are putting in it, it just boils harder. The condenser does the same in reverse, if you remove more heat, more gas turns into liquid, but the temperature stays the same.
Good idea & nice video. Consider also that for each Joule of resistive heating, many more have been lost in the production, transport and storage of this electricity. It’s nice to see alternative solutions being developed.
Yes, but the same applies for every Joule that goes into the heat pump ;-) But I know what you mean: energy efficiency is important in a world where much of the electricity is still produced by "centralized" power plants using fossil fuels.
4:25 ice engines are full of electronics plus electric stuff is very resistant to heat. And combustion engines are 100% effective (combustion won't just go thru cylinder wall) in terms of power but even heat can be used for cabin.
to put it simply, a heat pump makes one side colder and the other side warmer. for cabin heating you make the outside world colder and the inside world warmer. for cabin cooling you make the outside world warmer and the inside world cooler. its actually surprising that they even used resistive heating as that is just a short circuit with a fan blowing on it.
Heat pumps are highly efficient, but they have a little drawback: you can not use them as defogger while they are in heat mode. So, in cold and high humidity conditions you'll find yourself fighting to keep the cabin warm and your windshield fogless. So, I'm pretty sure that Tesla is adding a resistive heating element to allow the cabin being warm while using the air conditioner to dehumidify the air. Also, to be used in extremely cold environments where the heat pump coefficient goes down from 1.
You mentioned evaporator freezing into ince at low temps. Worth mentioning that most HVAC heatpumps have defrost function which reverses the cycle to cooling in order to deice the evaporator and keep it running in low temps. japanese domestic heatpumps are now capable of temps all the way down to -35°C. it would be interesting if Model Y has defrost function and thus can keep high COP :)
I like heat pumps. We've been using one to heat our house for many years. It works very well here as we never get the extremes of cold like they get in Scandinavia, Canada etc, but one thing to mention is that it takes longer to warm up than a resistive heater (something akin to a ICE engine warming up in terms of time).
Love the spoiler on the ICE car on the white board.