Yeah. Szymon and Adam are way too nice. And the problem is that $people can't avoid outfits like this if they don't know the names. I guess they are hoping that getting these designers to actually learn how to do it right will be more effective in the long run than naming and shaming. But _in the meantime_ people would like to know. Maybe someone on the development will tell us?
@@BristolHeatPumps I had alto design for me, did the day course and that, sounded good if I install the commission and take over. Did the install for a pal developer and now 6 months on we have realised there running shit. Done this a few times different companies designing and still the same issues. All new builds and expect a much better performance. Now I can’t trust anyone to do it and doing the knowledge with heat geek myself. That saying you want something done properly you do it yourself. That’s my mindset now.
@@stixstonesinvestors5413 yep they are shocking, tbf i would say most umbrellas are very poor quality, if only MCS had some backbone eh! We are a heat geek ourselves and do all our design in house, its really not difficult to do it properly
@@BristolHeatPumps so true. It really needs to be regulated and rules tightened up. I know a lot gas engineers who think they know it all and just have that mindset of it’s just a unvented system. They don’t take it serious and if they have someone design it and it don’t work, there attitude is I didn’t design it, it’s there thought. It’s such a challenge out there ain’t it. I truly believe the way forward is through heat geek. It’s bloody hard for me but im determined to finish this. Love your apart of it as well. Good to speak to likeminded people
In Poland, we have been using heat pumps for over 10 years without any issues, with 200,000 units sold annually. They perform excellently even at -15°C. In the UK, despite having milder winters and cheaper electricity, you always seem to encounter problems with heat pumps. Additionally, you regard heat pumps and heat recovery systems as something entirely new, it boggles my mind
When it gets a lot colder than -1, then the air gets very dry and the heat pump will only need to defrost every 2-3 hours. Between 0 and 3 degrees is the worst ambient condition for a heat pump, because the evaporator can freeze shut every 45 minutes to an hour depending on the operating point and this requires very regular defrosts. Therefore heat pumps can deliver more power and efficiency at -2 degrees then at 2 degrees. UK and the Netherlands have the worst possible climate for air source heat pumps, yet they make it work great anyway. The colder climate in Poland can actualy make it work better in some aspects.
@@andrewstafford-jones4291 The price you've quoted is more of a wholesale electricity price, without distribution costs, additional charges and taxes. As of now, polish households pay about $210 per MWh for the first 1500 kWh they consume this year, anything above that cap is in the area of $330-340 per MWh (and since that cap is quite low, anyone with a heat pump basically runs it on the more expensive electricity only). It is expected that as of July, electricity prices for households will be set at around $280, with no consumption caps.
@@andrewstafford-jones4291 oh please.. I'm paying ~0.25p kWh in Surrey, my mom in Warsaw ~1.15zl kWh (0.23p) Comparing prices to monthly wages, the cost per kWh in the UK is significantly lower.
Absolutely love you 2 have come together and now a 2nd vid highlighting these issues. You have to be so on the ball with heat pump installs. I know people installing them just following the design from other companies and I have seen an install which joules designed. I went out to see the install which was a pal that did it because the bills were astronomical. I could see clearly it was so wrong, 12kw on a small 3 bed new build and thermostats absolutely everywhere. I said to my pal about a lot of concerns but his reply was I just installed what they said it’s not my problem. I was like……. Geez you can’t be like that. Heat geek is a lifeline for all that wants to do it the right way. It’s so bloody hard but I love that. Simon you still the best out there, your content is the best, hope u 2 do more together and bring more light to this industry. Please keep them coming 👊🏻👊🏻
As a retired heating engineer from uk, i am not surprised at all by what you found, it is the usual situation of designers who dont understand the physics,installers who just follow drawings and may realise its not right but dont get listened too or dont care. And finally commissioning of the system, done by agents who probably dont understand how to set it up,or cant because the installation is wrong. THEN NOBODY IS INTERESTED BECAUSE OF THE MONEY NEEDED TO PUT IT RIGHT.
Another great video. You two make a great team. Really sad to see that new builds built to a high standard are being let down by shocking heating installations. Can't imagine what it'll be like once heat pumps are mandatory for all new builds; 2025 in England if im not mistaken. When an oversized heat pump gets installed for an old leaky retrofit, you can kind of understand why the installers go extra careful even if you know that a proper heat loss calculation is the solution. But with new builds it is inexcusable to get it wrong.
Blimey. That was pretty scary tbh. For those of us thinking about heat pumps, it's sobering to see "experienced" installers making such a botch of it on a new build property which should be easier than a retrofit. Caveat emptor doesn't even begin to cut it. Keep up the good work with these videos, really hoping that they can help drive some positive change.
Great video. Many of the ASHP manufacturers have a standard design or schematic that the installers have to follow to maintain warranties and provide sign-off to apply for RHI. For example, the Nibe schematic includes a heat buffer and my installer would not deviate from the design. I'm about to do another new build install and I'm faced with the same for an Ecodan system. Does Heat Geek have a schematic that shows best practices? Or a design listing best-in-class components. Are all of the manufacturer's schematics wrong? I'd love to see a video taking apart what's wrong with each manufacturer's design and showing a drawing of how it's done correctly rather than looking at homeowners' plant rooms, it's too difficult to see what's wrong. Fantastic job guys, I've been following your videos separately so nice to see you working together
It's down to the installers to specify equirement from manufacturers who care about this stuff. Bear in mind that a buffer might have been necessary in your property due to system volume. A buffer isn't automatically wrong, but they are often included when they aren't necessary, or where a small change might eliminate them.
Love to see your work. We are already 13 years telling clients not to do zoning, and we don't use buffer tanks. Use them only on very big systems where heat pump must have very high flow. Nice work, guys. I always enjoy watching you.
I love these videos, explaining how simple it can be and the big part is heating the whole structure as one. It is crazy how this was done to every house.
Since learning about heating, with the help of your excellent channel, i've come to the conclusion that it's not just the topic of heat pumps, or even heating in general - house builders for the most part, especially mass market ones, will absolutely do the bare minimum to (barely) meet the regulations. I am sure there are exceptions but most builders just want to smash houses out for maximum profit. I moved into a new build recently and a weather comp sensor was mounted to the outside wall, but not actually wired into the boiler. The sensor was only there so that it could (at a visual inspection level) meet the Boiler Plus regs. Of course, it's a bottom of the barrel combi boiler with a massive minimum modulation, so it cycles constantly, highly inefficient and will probably fail prematurely (at least then I can replace it with a properly sized unit). Radiators are barely big enough for the heat loss, certainly not suitable for low thermal design temperatures. I think the regs changed again recently so that more effort has to be taken to design for lower flow temps ... but im sure the developers will manage to avoid spending too much money on that ... rant over.
I didn't get the impression that these builders were doing the bare minimum to be honest. It seems like they just aren't aware of the best practices when installing heat pumps. They could probably increase their profit by installing lower output heat pumps, a single circulating pump, and not bothering with buffers, zones, e.t.c. Most people probably wouldn't even consider these things when buying a house so I doubt they would expect to pay more for them. Something that seems like madness to me is I've noticed a lot of new builds have high levels of insulation and air tightness, but then they just core 4 inch diameter holes in every room and fit hit and miss vents. At least this house has MVHR. Retrofitting MVHR is not worth it in most cases so most people will just have to live with that. If the builders can still hit the desired building energy rating without MVHR then it is easy to see why that is happening.
Also according to the video from UK radiators some sellers are not using the accredited verified heat outputs and quoting much higher outputs for their rads. If you are putting in radiators and heat emitters and they are not outputting enough heat you’re going to get issues. The industry as a whole needs not make sure there is top to bottom regulation and really heavy financially punitive fines if they get it wrong.
It's not just that most house-builders do the bare minimum, it's that they have been lobbying government for decades to keep those standards low. We should have had better building regs 20 years ago - the issue has been well-understood for that long, but the housebuilders keep whispering on govts ear 'if you make us build decent housing it will be 'too expensive' and we won't build so many'. It's not actually more expensive of course, for the householder. You save a lot more on energy costs over the building lifetime than it costs to build a passivehouse _and_ you get much more comfortable, less-allergic, quieter housing. And in places where they legislated for it (e.g Brussels from 2017), it hasn't actually cost any extra. Once it's standard a well-insulated airtight building (with a much smaller, cheaper, simpler, heating system) costs the same to build as a crappy one with a big heating system.
Maybe it's the Englishman house buyers? Just Google: 'false chimneys' - we have a house building program where fake chimneys get glued onto new houses where there could be solar panels!!! This year a new estate went up in our town where half the houses have pretend chimneys. Fake period features sell houses - not insulation or MVHR.
I'm not a professional but I can clearly see the logic here. All experienced contractors are doing the same thing they did since they ware installing the gas boilers which have higer starting temperature which is okay but at least there should be a new name for the Heat Pump installation and some guidelines when installing it. Should this be a part of a manufacturers manual🤔 As always thank you for your videos. Cheers 🍻
The difference is, poor quality boiler installations for the most part work, they are just inefficient. Poor quality heat pump installs, in the worst instances, do not work at all. And all costing 10x the price of an equivalent gas boiler. It's been a long time coming for all these poorly technically educated installers to get caught out!
Well, they work but they’re just outputting way too high witch causes them to short cycle which doesn’t work for an heat pump, where a gas boiler can vary gas level down to 1 out of 16 levels
The builders are Trivselhus and the largest houses on that development are nearly a £1m so that performance is pretty outragious considering the claims they make, perhaps a class action is required.
@@tonydaddario4706 On the contrary, I suspect these systems were deliberately over engineered to avoid possibility of complaints of poor heating from demanding wealthy customers. Some people can be very unreasonable, and we all suffer from people covering themselves as a result.
@@FlyinghookHeat pumps are quite common in the USA - mainly the air-to-air variety. But in the UK they seem to be considered new unproven technology. Boggles the mind.
Great video as usual, with some thought provoking stuff. Mind boggling that, on the face of it, a develeper has gone out with the best of intentions, and produced beautiful houses, but still got it so badly wrong. A couple of things immediately spring to mind....... 1. We need a list of pertinent questions that buyers of such houses need to be asking before they sign. 2. You hint that they are a large well known outfit but you don't name them. How does the unsuspecting public know if they never get called out?!?
Great video as per usual! The larger point is why is it even legal for installers to be doing this with limited customer comeback? How many billions are the government wasting because of inefficient installs? Imagine the needless load this will put on the grid at a national level vs. if we had well-installed heat pumps? It's really sad to see. This is a fantastic example of installers not understanding the technology and making things needlessly complicated. - More expensive to install due to the excessive sizing & extra, redundant parts - More expensive to run - More errors (some of which balance out, but many of which compound things) - More maintenance required due to thrashing/cycling, plus engineers will have to have their wits about them if they want to understand wtf is going on - More to go wrong in future because of the extra complication
Not sure 'The government' is wasting billions here. It's people buying houses (which could have been cheaper) then spending more moeny to heat them than they should be. So it's individuals/families wasting money (and installers who could do a better job much more cheaply if they actually knew what they were doing).
@@defragsbin Sure, the last 20 years of failure to set decent buildings standards has been a huge contributor to the current cost of living crisis and has wasted a great deal of people's money (on expensive heating) and government money on the poor health that poor housing generates. I actually blame mass housebuilders as much as the government - it is they they have been campaigning to keep standards low for decades (and the govt is too innumerate to just ignore them and do the right thing for the populace anyway)
We have a couple of problems in the UK - old and poorly insulated homes, gas prices are under 1/3 the cost of electricity meaning you need a COP of @ 3.5 to financially breakeven if you move from gas central heating to heat pump. Lastly, and what these guys are championing, our heat engineers are trained mostly in safely installing the gas central heating and not optimising and design of heat pump systems. We are definitely behind our European neighbours but channels like this are helping.
you don't get 1kWh of heat for 1kWh of gas. average gas boiler efficiency achieved (rather than the badge efficiency) is about 83%. so you only need a SCOP of about 2.5 to break even on running costs at gas costing 1/3 of electricity
They’re not even trained in installing efficient gas systems, The gas safe qualification is just that and nothing else I’d say 80% of guys are of the “Fit a 40kw combi mate” mentality.
The gas central heating systems in the UK are absolute cack too. A typical gas boiler is big enough to heat more than five houses, and runs much less efficiently because of this- the return flow temperatures end up much too high, and so they don't condense properly.
@BooBaddyBig they never condense in the Uk and they fail on average after 8 years making UK a cash cow for boiler manufacturers and a haven for cowboy combi slingers - couldn’t make it up
Really enjoyed this video Szymon, I am the renewables manager for Alpha. I would love to invite you down to see our new heat pump and cylinder, I think you will find it refreshing. Ps. We’re only down the road!
A great video, thanks. Worth noting that the 11.2kW Ecodan is a power limited 14kW unit, with the same minimum output as the bigger version. Also that Ecodan apparently have a firmware update for excessive cycling that they only install if someone complains. My experience is that the 11kW Ecodan cycles rapidly whenever the heat load goes below about 6kW.
Mitsubishi has a big problem with truth when we talk data. The units do not deliver what is on the data book. My 8.5kw does no modulate below 4.5kw when it should go to 3. The energy and cop data displayed on the unit are also completely made up.
@@aymerichousez1005 Not defending Mitsubishi but I think if you were to take away all the supporting hardware and do the testing in a controlled environment, I'm sure you'll get good results that match the book. My 11.2kW is returning about SCOP 4.1 and I think it's just down to running 1 circulator, no hydraulic separation, no 3rd party controls, no TRVs, good emitters, good system balance, no glycol and fairly low flow rates as it's oversized and never needs the full output. Internally these units are 90% the same as the best performing ones from Vaillant, Viessman etc, it's all the pre-plumbed and 3rd party nonsense that drags it all down. And Glycol!
@@Loopyengineeringco I would say that unless you use a 3rd party monitor, you don't know what your cop is. I was at first impressed with the COp shown on my ecodan but when I started to monitor temperature and electrical power independently, I realized that these values can't be trusted. The temperatures are rounded and the power is corrected somehow to makes things looks good. Whatever they claim from test conditions, the competition performs better. I don't believe that these units are all the same. A Vaillant 7kw weight 190kg, a Mitsubishi 8.5kW is barely 100kg...
@@aymerichousez1005 Yeah definitely don't trust the estimates, I'm using a ultrasonic flow meter (ofgem supplied calibrated unit as part of the MMSP package) and 3rd party CT on the consumer unit to do the calculations. I think you're comparing different chassis sizes - the twin fan ones are naturally heavier. But like for like, you're right in that there's still a bit of difference. Vaillant use piston compressors vs scroll compressors on the Mitsubishi, maybe they have more ballast for damping, or thicker casings? Not sure! The Mitsubishi is definitely a lower quality product though for sure, although I do like the controls, AA mode is really good, external API and hackability etc
Run it at a constant 20 deg over a winter and you get the real heat loss. UK builds have missing insulation, air leaks so I wouldn’t ever trust a drawing.
passive house spec is 10w/m2 peak load. So 2kw. Worth mentioning that passive house on big developments with simple thermal geometry it only adds 2-5% onto the costs over building code.
@@Swwils There could be an argument that a better designed house would be easier to construct correctly. Dense packed insulation between double stud walls, for instance. But the UK is attached to certain ways of building (brick leaf, insulation, concrete block, dot and dabbed plasterboard).
@@Swwils Research on real PH builds has found that they actually have a very good record of meeting their design specs, unlike most UK mass-build houses. Because you actually have to pass a fairly stringent airtightness test, and design out a lot of the stuff that brings houses down (thermal bridges, thermal bypass), it's actually _easier_ to build it so it works like it was designed. Said researach was published in passivehouseplus magazine a couple of years ago.
THANK YOU! I am commissioning an underfloor heating system right now. I thought it was a bit overengineered and you've confirmed it. I'm going to remove 3 thermostats, 4 actuators and most of the wiring centre :)
I've heard that the Manual J calculation used in the US for calculating heat gain/loss is overly conservative to begin with, then installers pick a higher summer temperature and lower winter temperature to reduce callbacks, and then pick the next bigger size heat/cooling. This produces oversized units which are inefficient during spring and fall. But what was surprising to me was that unit sizing didn't seem to be done at all before designing the heating system. In most places in the US, it's not possible to get a building permit before sizing the HVAC, and you can't size the HVAC until the windows are selected so the U-values are known, along with insulation and air leakage targets, validated with a blower door test. The other surprise is that I didn't hear a dehumidifier mentioned. Perhaps that's not a big problem without a cooling cycle, but things like showers can throw a lot of humidity into the air, and with a passive house, a typical bath fan will depressurize the house, and not do much to actually exhaust the humidity. The ERV can help, but only if the bathroom fans are instead the source of the ERV exhaust air.
For anyone considering a heat pump, do your homework extensively. I recently got a heat pump installed and I pretty much knew the size of unit I needed before the installler came around. Micheal Podesta’s channel is a good place to start.
Don't fit North of Manchester..the ambient temperature is way too low plus winters are long and very cold...have loads of experience with this..@@UrbanPlumbers
Interesting film, as always. This really underlines the problems with everything UK, too many people involved with each stage thereby each one sidesteps responsibility, but all of them wanting ‘a cut’ . Too many vested interests for it to change. Until we get some proper standards that are strictly enforced and organised/accountable, we’ll never improve.
Amazing video chaps, great job! Really getting to the crux of the problem within this industry. So called 'experts' throwing this nonsense in, thinking they are doing the right thing. Most of whats installed in these houses is just not needed. KISS! As always the haters will blame the heat pump, when in fact its just lazy 'copy and paste' designs from home to home using the 'thats what we've always done' method of system design. The only people who suffer in all of this are the poor homeowners who have to live with a poor system and pay crazy money for their comfort. Manufacturers are also to blame for producing this nonsense that does nothing for good efficiency. One other point to note that I haven't seen mentioned here, is the longevity of the heat pump in this situation, the compressor is likely to fail within 5 years here too, probably just outside of its manufacturers warranty too!
Looks like the developers of that estate have a way to go yet, though still heaps above the others. I'd love it if you guys - Urban Plumbers & Heat Geek et al, - could get in touch with them and help them on the road to doing 'all things heat pump' the informed and Heat Geek way. After all, what is info and training if not to disseminate and inform the masses. . . .
I guess over specifying means more money from the developer (and ultimately customer) for the job. It’s the heat pump equivalent of a 30kw boiler in a 2 bed terraced house.
This model is an 11kw unit, they're marked on their actual output not input. So it's an 11kw heat pump (which should be about ~3kw input). Still this is hugely oversized, should be
@@UrbanPlumbers yep, so he shouldnt be doing any zoning (and this assumes he wants the entire house at the same temp, of course) I mean, what, 100L + volumiser to reduce cycling, even with the open zoning... were your calculations at -2c?
Great video. Oversized heat pumps are a problem though some can operate very efficiently at lower power. This is sometime the silent mode or something like that. That does require inverter technology which I would always recommend. Some additional tips: the cover of the terraced house lady should be removed. The air should flow unrestricted through the outside unit. Installing the outside unit low is actually not good. It has a much easier time circulating air if it is slightly raised. Especially in an area with many walls nearby. On cold nights with very little wind you will get recirculating of cold air back to the outside unit. This makes the unit operate as if it is noticeable colder. You want as much warm ambient air to be drawn in. If two rows of houses with backyards facing each other all have heat pumps they will cause local cooling. Cold air stays put. With AC the out out is hot air which will always escape upwards. COP goes down if the inlet air cools. If there is a small amount of recirculating air it will be a vicious circle. Thanks!
Oh dear, what a shame. A new build should be a perfect opportunity to get a heat pump installed correctly. Hopefully the developer will learn from this mistake, although they were probably just following manufacturers schematics for the hydraulic setup. On the plus side it's great to see heatpumps being installed in new builds, even with a disastrous cop of 2, they are still lower carbon than a gas boiler!
Pretty disappointing when you buy a high end home for a premium over standard new build to have such a poor set up. Manufacturers are at fault here too - some pre plumbed “fits all” system are awful and also more expensive - more education needed for manus and installers but also for developers, so they can chose batter subbies
In Germany, heat pumps got magically cheaper after state subsidies have decreased. However, pumps were hard to get because everyone wanted to get a gas heating before they were allegedly not allowed anymore. We were trying to work with a local company that only worked in the heat pump business for over 20 years now and had a pretty good reputation. Unfortunately, they couldn't keep up with the demand - became rude and unreliable; google rating dropped vom 4.x to now 2.3. We're still looking for someone and they all ask around the same amount: 500-1000 Euro above the state funding limit, flat. At one company, you would sign a contract first and then they take a look at your situation.
This is the case with all "new" technologies that have government funding, the price charged by approved installers becomes the open market price plus the government grant rather than minus the grant. It happened with solar panels and EVs in the UK, and now it's the same with heat pumps.
@@garysmith5025 We are now signing a contract with a company that seems competent but is located 300 km away from us. Let's see how they fulfill their service contract...
Oversizing is bigger problem than undersizing. Of course, you cannot go too low but for such a new building with very heat loss it is crucial to not oversize the unit. The main problem is minimum modulation on 90% of the year which is usually above heat loss if the case is like you explained here.
It's almost impossible not to oversize the unit because you can't actually buy 2 and 3kW heat pumps yet. (fx:checks) Actually I see Vaillant have a 3.5kW ASHP now (and the old 3kW Geotherm).
Long ago, I did oil heat work here in the US. After hearing your description of the house, my first thought was 3.6KW or 3 ton as we would call it. Most installers over here would probably bump it up to 3.5 ton to avoid complaints figuring the customers won't notice the lower efficiency. 11KW (9 ton)???? Wow.
In the UK, you'd expect it to have to run in three coldest months for heating, but for the rest of the time, it would only be needed for heating domestic hot water. (The heat loss from the humans, electrical devices and DHW storage and pipe work would keep the house warm the rest of the time)
Oh lord. You should see what they do over here in the US. They even talk about "heat pumps" like they're some new technology that the rest of the world hasn't had for 10+ years. Over here they regularly oversize heating by 4x or more .. nobody even does load calculations
I have underfloor heating in my kitchen and it has two zones controlled independently. UFH uses radiated heat so there is a very good reason to zone it. If you are standing aound a hot oven and active you might want your UFH to work at a lower temperature. You can do this with floor sensors or room stats to shut off zones . Over in the dining area where we also have some seats to relax and watch the television it is nice to have a slightly warmer temperature, Using your open zone method doesn't allow for this. The fact that a heat pump can't cope with this setup is a limitation of the technology.
You guys seem to actually understand how things work , unlike most plumbers. Please enlighten me on one topic. Ive installed in my house on ground floor two vertical designer radiators upside down, and connected them on the top. It was way easier to run the pipes from the ceilling down. After doing that, I've asked on few plumbing forums and Facebook groops if I've done right, or i should expect troubles. Most plumbers advised that there's no chance that it can work, for various reasons. Now, after 3 winters, I'm happy to report that the system works absolutely flawlessly. So im asking you, how come no plumber could see that the system might work, and why I could see that it should work, even if im no plumber at all. Thanks
and then you will not have any choice to get those - even worse: the smaller houses will have an even lower demand which the modulation can barely cover except turning the compressor on and off and cycle
Where do you get 20-22? All the documentation I can find says ≤ 10W/m2 passipedia.org/basics/building_physics_-_basics/heating_load www.passivhaustrust.org.uk/UserFiles/File/PH%20Intro%20Guide%20update%202013.pdf
When I see a new development where the houses feature heat pumps, it makes me less inclined to purchase as I have little confidence, they will have correctly sized all the components. The same goes for the token couple of solar panels some developers are installing just to tick a box. Really pleased with the Vaillant ASHP system installed by Libtek (Alex is one of your Heat Geeks) in our current home. Next home may have to be a self-build or another home with a gas boiler that needs replacing with a Heat Geek installed heat pump.
It's worse than you think. I know of two passif home builds just completed. Both have heat recovery air systems. The heat pump installation is by different companies. Both heat pumps are large. What you would calculate for a gas boiler perhaps. I asked the home owners if heat loss calculation on the new builds answer. Don't know. One home just running temperature set at 45c. He already complained to me about the high electricity monthly cost. The worry is these companies are using these new passive homes to get more work..And messing up the insulation
I came from a geothermal heatpump background started almost 20 years ago open circuit large pipe low temp system simple avoiding distortion accuracy when sizing exc...was actually easy then as general public knew nothing so could do as you pleased nowadays public are difficult want and expect it to be zoned everywhere if you don't supply what they want you don't get the job they think your the hack... Also Installing well is only half the story very few people can diagnose and repair any kind of heatpump when they get older few years pass quickly. Also manufacturers charge too much for parts older machines tend to become economic rightoffs once 7 or 8 years old too chancy to risk expensive repair... manufacturers need to be tacked on this and shamed talking of lowering carbon and then setting people up with esentialy a disposable heating appliance....
This video is revealing 2 problems: - the lack of competency of some system designers - the false data advertise by some HP manufacturers, namely Mitsubishi. You cant design right if the manufacturer does not give you the right data. These issues on Ecodan are so recurring, Mitsubishi is just waiting for a consumer action class against them... Government should act and make sure that what you get is what is advertised.
2kw thermal loss max for the house. you will be looking at 500watt electrical consummation of big 8-to-10kw heatpump will be cycling. cop around 3.2 because of no losses
The "Passiv" part in Passivhaus was meant to mean that no (or little) active heating or cooling is required by means of thermal insulation, ventilation with heat recovery and proper use of solar gain and shading. It seems to me that these houses don't need hydronic heating at all. A modest floor standing AC unit in the open plan space should suffice. That's how these scandinavian houses were designed. The MVHR takes care of equalizing the temperature throughout the house. This way you save space, you save on installation and you get rid of those radiators upstairs. It's as if the architect did not feel responsible or the builder did not look at the plans.
Indeed. So are they actually PH, because that doesn't fit all that well with the ~3kW heating load Adam and Szimon calculated. They were presumably not accounting for solar gain the way PHPP does.
I live in a new build with a primary energy use of about 27 kWh/m2. We have a 700W MVHR combined combined heatpump and MVHR and backup direct heating which is off 90% of the time in winter. The biggest compalin I have is that the system isn't powerful enough to fight the solar gains in the summer, which means you have to open the windows (and I'd rather not since I'm allergic). I believe that new builds should have external shutters to fight off solar gains in the summer which can'talways be easily retrofit. In short, solar gains are more important with very energy efficient homes. you can't simply create an airtight and well insulated box. You need to take shading very seriously too.
@@Takethis42340 Yes, absolutely. Overhangs and awnings are such simple and effective pieces of technology that have been around for centuries, but seem to be forgotten in some countries. A well-placed deciduous tree might also do the job.
Question on the SCOP figures for a super insulated house like these. Would it be lower overall as the system should spend more time on heating the hot water rather than heating the house? Just thinking that it's usually the heating cycle that gets the best COP vs HW so does it skew the numbers a little bit? I would have assumed that they would be in the 5+ figures for SCOP but if there is little heat demand this would drag the average down.
Yes, that is likely. In a house at PH level hot water load can be quite similar to space heating load. It might even be higher. And COP is typically lower on DHW than space heating, so you are correct. But it's a slightly lower SCOP on a much lower total heat/energy load, so it's still all good.
This is a sad indictment of some of the profession that this standard of workmanship can occur at all ? "The more experienced they are the less likely they are to be good "! What a terrible shame. The experienced people in the industry should have a head start and be therefore be better ? With all the bureaucracy and planning that is meant to be done prior to the installation, how does this happen ? Perhaps a "Gas Safe" model should/could be ado[ted where a person completing the work automatically becomes responsible for it in the future ? Should there be issues, a body mediates between the house holder and the installer has to correct those installations ? Good work and diplomacy (as always) from the Adam and Syzmon from Heat Geek and Urban.
6 місяців тому+4
I do confirm what Adam says, for my country. Here in Belgium the old chaps', in the trade for 40 years, are totally unable to design a system. They just eyeball it and reproduce what they have learned 40 years ago. Your old (atmospheric high-temperature) gas boiler was 25 kW ? "I'll put you a 30 kW so you're sure you won't be cold in the winter." And the said new boiler is a condensation gas boiler, triggered by a stupid on/off thermostat, barely modulating its power, almost never condensating because the flow temp is set on 75°C, and the thing breaks down after 4 years because it cycles 3500 times a year... The owner did invest into insulation and eventually the house had a heat loss of 4 kW. And that happens ALL THE TIME with the old' chaps, the "very experienced" ones. The young boys who learned to *effectively*¨apply the EN 12831 standard and *really* use the method, they do a great job. I've been training to design heating systems and in the room there were two old' chaps which were there because, they said, they didn't understand anymore why the new boilers fail and the suppliers told them repeatedly to get a training to learn to design. The others trainees were design engineers from design companies which were asked by their bosses to review their design methodologies to get less failing installations and less unhappy customers, and make the company ready for the heat pump revolution.
This system does seem terribly complicated! Obviously you've got to work with what's there already, but if starting from scratch in designing a building with MVHR, would it make sense to look at air-to-air heat pumps to avoid lots of plumbing (I'm not an expert)?
As an engineer I approve of this message. Simpler is always better and more reliable. I am surprised the middle townhouse has the same big heat-pump. That's just silly.
Unfortunately, in our litigious blame culture, naming the developer & installer is more likely to generate legal action instead of a cry for help and support.
Excellent presentation as always , these are all aspects you have talked about before but this time all in one place , I hope you have the chances to re fit some of these system so we can see the results
Ive installed one of those chinese 18kw pool heat pumps all in ones...just had to pull and connect two pipes to my old heating furnace. A fraction of the cost and free install since i did it myself ( gas is already built in). So far it works great, even when it was -10c this winter.
Why am I enjoying these car crash ASHP post-mortem videos so much!! These poor, innocent home owners have my sympathy. No heat loss calc, oversized unit, basic plumbing mistakes, over engineered UFH, the list is always the same. Not sure if I would want the ASHP so close to the ground, I would be surprised if the manufacturer doesn’t specify at least 200mm clearance. Also not too happy about the casual attitude to the ACH (air changes per hour) guesstimate. Need a blower door test or at least the as-built SAP documents. The MVHR install looked a bit ropey and judging by the ASHP install, probably also needs to be reviewed. The problem with all this is there is no reasonably priced solution to remedy all this. Other than a new ASHP the right size, what can they do?
A bit of DIY is a reasonably-priced solution. What's really annoying is that all the grant schemes explicitly exclude homeowners so after you've worked out how to do things properly by taking an interest in channels like this and other fora, and worked out that you can a better job for half the money, you are excluded from incentives. They are trying to keep the cowboys out with these schemes, but as we observe it doesn't really work very well. There is also a strong tendency in government to _actually_ only care about the job-creation part, not the _outcome_ of better, lower carbon housing, which could be provided dramatically more cheaply if we let people help themselves. I DIYed my MVHR for example. It cost about £1300 total for a 3-bed detached (and 9-days in the landing cupboard and loft over Xmas cutting tiresome spiral pipe :-), oh and quite some time making a nice 1st-principles design spreadsheet). Plenty of people could fit their own MVHR and would make a neat job of it. It's not rocket science, and even the design is easy if you use a manifold system. ua-cam.com/video/OVcvk9Wnyw4/v-deo.html
Absolutely shocking. If the installer is MCS certified, simply report this estate to MCS and let them take action. If MCS won't, proves that their 'monopoly' is a sham and no proof of competence. I'm a fan of Urban and Heat Geek - intelligent thinking from first principles, although it's all quite simple really. I'm a professional engineer, so reluctant to join MCS, but not allowed to access BUS without doing so. I know someone getting a HP under the HUG scheme which is PAS2035 based. Five companies involved and not clear who is responsible for anything, so will be interesting to see what problems that throws up.
@@persona250 Agreed, but the boys tell us this was a large installer, so would expect them to have MCS so they can pick up other work. That aside architects are seen as competent professionals by PAS2035, so why would they specify a badly designed system, or contract out same? We seem to be supporting HG's comment that a challenging mind is better than an experienced mind :-)
Great video. My 11.2kW is on a 6kW heat loss property, and that's already oversized 😂 adding volume & load really helps, open loop everything. Also weirdly, the firmware on Auto Adaptive allows a lower modulation than on WC, mine runs down to about 1000w input watts. Go on, who's the installer?
Are you serious? You get lower modulation with the auto adaptive than with the WC? Every time I tried the AA, it was running the temperature so high that I thought there was no point. The general feeling I had when talking to people on FB groups was that the scop on AA was very poor.
@@aymerichousez1005 Yeah, the trick is in getting it to 'learn' correctly which can be difficult to do. AA is basically extra smart WC, so using the wireless sensor for feedback it will build it's own flow vs outdoor temp curve (internally, not accessible to the user). But to get it to build this curve you need the wireless sensor/stat in a good place and as open loop as possible, rads, underfloor, everything on max flow and this isn't documented very well, so most people give up when they see the system going full out. It will massively overshoot to start with, then on subsequent runs it will use less and less compressor to achieve the same internal temp but with longer runs at lower flow temps. Once it settles after a few days, I found it generally allows the compressor to run slightly slower than on WC, and for longer periods. WC also seems to have a massive overshoot to begin with, which AA mode doesn't exhibit. I did question Mitsubishi about this but they're not interested. I think a lot of development went into the AA side of the firmware and less for WC. AA is a closed loop control system with feedback, WC is simple open loop
@@Loopyengineeringco Interesting that Mitsubushi were not interested. I think this happens when the local support office feels that they cannot influence the engineers who actually write the software. It's actually a very common attitude in the UK.
I can't see how you'd do a follow up video this year - there's no way the heating should be needed before November at the earliest. Even in winter the occupants, TV, fridge, lighting, phone chargers etc should be enough to keep the house warm.
Passive house insulation plus MVHR - finger in the air at -2C and 200m2 (similar to my similar bungalow with average insulation and newer windows which is 6.kW according to my calcs) so I reckon 2-3kW heat loss?
I spoke to an installer recently who said he always fits 12kW heat pumps. When I replied that it would be much too big for my house he said that it was no problem because it would modulate down to the required output. I didn't take the conversation much further and I intend finding a Heat Geek although there aren't many in my area.
@@UrbanPlumbers My 12kw boiler can only modulate down to about 8kw. I only need 5-6kw so it cycles a lot. I've had to replace the ignitor several times since moving in, as it bends out of shape from heating and cooling constantly. Very annoying.
@@UrbanPlumbers Adam said in the film they don't even make heatpumps small enough for that installation (3kw). Wouldn't you have to rely on oversizing and some modulation?
@@tonydaddario4706 There is a minimum output that the units can run constantly at, any lower demand and it’ll start cycling (i.e. running too high for part of the time, switching off for a while, and repeat). A 5kW unit should be able to run at 3kW, but an 11kW unit like in the video probably just won’t be able to…
14:18 yes, you can get HPs that small and actually smaller. Just not the style you're looking for. Also note that the minimum capacity for that unit is about. 3.5-5kw. (depends on conditions) it's still too big for the house but not as much as it seems at face value.
I don't know. I'm pretty glad I just have a simple aircon or minisplit (US term?) system; i.e. air-to-air. It's way efficient, simple and indeed cheap. It cools during summer too - which is a nice bonus. The Panasonic I went with has a 5 year warranty too, which is great.
What i find interesting is you always say one pump is enough for entire system. When i was installing Under Floor Heating, they said I needed a manifold and pump per floor? I wanted a central manifold for whole house, was they incorrect?
Random question - does having multiple zones (my house has 6 on the ground floor) cause issues with flow balancing? I figured the system was balanced to create equal flow through all the zones, but if they are turned on/off for various reasons, does this mean that one room may get starved of flow depending on the length of the zones the happen to be on etc?
Excellent video and very thought provoking. Such a shame a premium developer produces these beautiful expensive houses and so utterly fails on the heating system. Thinking outside the box - I think you said 18 properties , so say 60KW heat loss max - maybe they could have put in a ‘district solution and just fit heat meters in each property, maybe splitting the development in two, so two 30KW plants maybe consisting of two cascade units each. BTW did you tell the young lady the cover on the pump ain’t helping?😉
Can't believe they installed an 11kW unit in a house with a heat loss of 3kW......I guessed 4 and I'm just an enthusiast. I've recently had a quote from British Gas for a Vaillant 7kW unit but as they said I needed every radiator replacing it was £8000 with the BUS. Well out of reach for me sadly.
That's BS becasue you can usually cascade the exisiting larger radiators to smaller rooms if necessary and don't need all new, but of course they don't want to do that, partly in case a radiator they move fails etc. but mostly because they have a one size fits all approach that assumes replace radiators as required by planned flow temp and heat loss of each room. Find an installer who will work with you to do it more economically.
@@jabberwockytdi8901 Basic radiators are pretty cheap to be fair, a significant part of the cost is labour replacing them, even then, not so much. I just had 6 rads replaced as they were ancient and I didn't want to paint them again, cost me ~£1.2k inc labour; the radiator replacements aren't the cause of an £8000 cost with grant. That's due to other factors, like the existence of a grant pushing up all the costs by... about the amount of the grant! In a property anything like mine, all the radiators are different sizes, which would make attempting to cascade them a pain due to all the pipe adjustments required, whereas a lot of the radiator upgrades involve same length but increasing the height / depth, much simpler. It's not really that practical a solution to cascade them, and not something you'll ever see any large co wanting to do as a matter of course.
Interesting video, when I install heat pumps I always oversize. The number of times I get told it is a high efficiency home when clearly it's not. You can never get more heat out of an undersized HP but you can wind down an oversized heat pump. Clients complain bitterly about the house is not warm enough but rarely complain about heat pump efficiency. As well as heat pump suppliers have standard HP sizing and installation requirements. Go outside those parameters and you are on your own, even if the heat pump is not performing correctly. Cheers from Oz
If it was me, I would size the unit to exactly to meet 80-95% of optional heating requirements and then an auxiliary electric small boiler for the rear moment the heat pump falls short
@@patrickwheeler2646thank you. I looked them up and looks like they are also a big box company. They give an advice based on data given from the customer. There is no heat loss calculation......
@@patrickwheeler2646 They are somewhat, but education of design or more likely retrofitting is not very good. There's also people who do it themselves with a air to water system and just dump heat in the normal radiator system. Some people will replace wall radiators with fancoils (they have active low noise fans that move the air across the coils)
Dear Szymon and Adam! Amazing video. I am a viewer from the Netherlands and I would really love to do a heat loss calculation myself for my own home. I know all the R/U values etc. How do you do it ? Is the app available for home owners to use? I would love to pay a single fee to do a calculation for my own house.
Curious to know what happens when a heat loss calculation is done, but then later on you find that the developers have left gaps in the insulation, skimped on it in some locations, or not installed cavity insulation properly. This would result in the house not getting quite get to temp when it's really cold. Would you need to remove the smaller heat pump and install a bigger one, if the insulation wouldn't be an easy fix?
You could just suppliment the heat pump with electric heating. The heat pump will be correctly sized for 355 days of the year - for the two weeks of really cold weather, you can just apply some local heat. Fixing the insulation would be the best action, as the losses will continue for the next 100 years or so.
It’s also rare that the heat pump is perfectly sized for the stated heat loss, e.g my heat loss is about 4kW but there are few ASHPs that are rated at 4, most are 5kW. So even if something wasn’t quite right, there’s another 1kW to play with too.
Great video love the collaboration with Adam! I'd love to know who the installer was ;) If I'm honest if someone approaches them with constructive feedback and they don't take it on board for future installs they should definitely be named and shamed!
I have a 220m² passive house on 2½ floors (warm loft with 2 rooms on 2nd floor) now 7 years old. Our winter heating load peaks at around 50 kWh / day but the Dec/Jan average is a lot lower at maybe 40 kWh/ day. DHW typically varies between 1½-5 kWh / day depending on use. UFH in a 17t "warmslab" on ground floor. Nothing on upper floors I put in a 3kW inline resistive heater at build, plus a couple of oil filled rads on 1st and 2nd floors to do top-up Dec-Feb. The whole house is run as a single zone at just over 22°C 24×7 (though the 1st floor is typically about 1° cooler). All heating done using minimum price-slots on an Agile ToU tariff. I had initially intended to fit an ASHP after a year or two when the house's thermal performance had been fully characterised. However, as I only spent about £400 p.a. on electricity for space heating, so I can't really justify much more than £4K for the total ASHP install. MCS quotes are a joke: 11kW ASHP and 4-5x my budget. 🙃 But thanks for a very good discussion of the challenges that owners of passive or near passive class owners face.
BTW, my problem isn't with ASHPs ; it's with the UK bureaucratic and regulatory framework. I have a house designed to take a ~ 3kW ASHP for slab heating only; a buffer tank would be entirely redundant. The water flow/return + supply were installed when the house was built, but this approach falls outside permitted development scope as MCS registered installers will only consider a complete replacement which is again totally unnecessary, I am ineligible for a BUS grant and also need full planning permission to install a very simple ASHP solution. Absolute nonsense.
@@rogerphelps9939 Not sure why the channel owner deleted my response to this; poss because I linked to another UA-camr that did a timelapse of a build like mine to explain the slab construction.. No storage heaters. The entire 17t slab and the internal fabric of the build is inside the thermal envelope and acts as a heat battery. Last Jan, I had a bug on my control S/W after a change on the UFH heating and it was out for a couple of days, because by then we noticed that the house had lost about 1½°C -- enough to notice.
This is what you get if you design for individual components, rather than as a whole system. Having said all this, the difference in running costs at such low heatloss values / operation, will only cost an extra £1 / day in winter to run. i.e. it goes from £1 to £2 a day.
@@normanboyes4983 These are super well insulated houses built to higher standards than even the current building regs. They really don't need much heating. The whole idea of a 'passive' house is that the heating demand can be supplied from the waste heat from cooking, lights, hot water and just living in the house. I imagine that they only need to turn on their heating in the middle of winter.
My initial thought is if built to Scandinavian standards, and almost passive house with MVHR would make it ideal for an Exhaust Air Heat Pump, so sub 5kW. Lets go with 3.5kW
@@UrbanPlumbers But the 3kW heat loss is calculated at what outside temp (-2°C?) which it hasn't been in England for some time, so clearly this house hardly needs any heating at all at the moment. It will be getting enough from the appliances and people inside. Which means the heat pump is probably only doing DHW and for a High Temp ASHP a COP of 2.2 is about right for hot water. If you put a heat pump of any available size into a house that barely needs heating but still requires hot water, you're going to get a poor COP.
@johnhunter4181 scops for heating is 2 and for hot water 2.8 I think - all figures are in the video for all house types. They all have heating scop of around or below 2 and DHW scops of around 2.5
Same story here, in Switzerland., lack of engineering knowledge and possible conflict of interest (it's more profitable to sell an overpowered pump) all work against the customer.
i have the preplumbed cylinder and the filter is already connected to the flow side and pump below for the recirculate to the hotwater heater for cylineder so big error from Mitsubishi.
The whole heat pump roll out is being done like a boiler lift and shift with a few tweaks. My learning from all these videos is that it's a new concept altogether. E.g. run during the day when it's warmer, (over 5C), and have a massive heat store and thermal mass keep you going for some time. E.g. 100 litres of water per meter squared of ground floor area. That's a lot. 10 tons from 21C to 40C is 19* 10*1000*1000*4.2 J or 190MJ, divided by 3,600,000 giving 52kWh.
The fact we don't run dehumidifiers for shower rooms blows my mind. High water vapour content hot air is free heat. The lack of a heat exchanger on the outflow seems ridiculous too. Simply wrapping the cold input around the outflow can reduce hot water requirements significantly, while not affecting peak temperatures available. A 10 min shower will use around 1.5kwh of electricity. For a 2kw house with 2 people running a heat pump at COP of 3, heating power would be 16kwh/day. Showers would use 3kwh per day. In this conservative situation ~19% of power goes towards showers, and they are doing nothing to mitigate that. It is actually significantly worse than that, because if you are opening a window you are deliberately expelling air without putting it through the heat exchanger, meaning the air that replaces it will be cold and need to get heated. I know it was a throwaway comment, but the complete lack of work on making showers energy efficient bugs me, because there is a lot of low hanging fruit there.
Very interesting presentation, especially when that system was investigated, and all of the installation faults were highlighted... Obviously, I'm no expert, and I'm going to take what was said as a statement of fact: so my question is... if all of this is true - does the customer have the right to insist that the installation company comes back and rips it all out and redoes it properly (free of charge, obviously)!
I see there is interest conflict for original installer, all comments and on neighbours installs, mention extra unnecessary hardware and labor which is good for business but bad for customer. New installers value good feedback to get new customers via recommendations , while experienced big companies don’t need good personal feedback to keep business running. Very good point about temperature difference in connected areas, all most impossible.
The only way to improve public confidence is by bringing the building regs (Part-L) up to an adequate standard that protects the consumer. Correct me if I’m wrong, but where does commissioning and provision of information set out that a heat loss calculation is provided? Part-L’s efficiency for heat pumps (Table D) also only refers to efficiency as 250%, but commissioning as set out by section 8.9 appears contrary that it should be in accord with ‘manufacturers instructions and appropriate system design parameters’.
This Govt were so concerned about public perception, that they commissioned Nesta to do a survey of MCS accredited ASHP installs that paid respondents £250 just to complete the survey. So no bias there. It found that over two thirds of even the MCS accredited installs relied on a secondary source of heating, of which around half had installed a wood burner. Nesta thought it not necessary to ask why so many rely on secondary heating.
Having been designing a 5 bed Passivhaus for a while, I guessed the heat load would 3kW! I would have liked to have seen more discussion of the impact of domestic water demands on the heat pump size. These properties seem to have been provided with large storage cylinders to allow lower temperature water to be stored.
You are right that DHW can be about the same load as heating once your house is efficient, but unless the heat load is such that the heating is running al 24-hours there should be enough time in the day to heat some hot water as well without actually increasing pump power. I don't think anyone tries to do both at once do they (except maybe Atmos gas boilers)? How does a bigger cyclinder let you store lower-temp water? The minimum temp for a useful shower/bath doesn't change by cylinder size. It's ~40C/45C respectively. And 10-60l (people vary wildly here). Do you mean that if you are in danger of using all your hot water in one day then you could raise the temp so less hot water volume gets used by each shower/bath (and more supplied by cold)? That's the same as saying 'your tank needs to be big enough for daily usage'.
Ecodan cylinder needs a separate pump as it heats up the cylinder indirectly using a plate heat exchanger. But you could remove the other pump and run the heating system on 1 pump
those systems have 4 pumps. 1 for the external unit, 1 for DHW, 1 for rads and 1 for UFH. - 2 of them can be easily removed. Those mitubishi cylinders are a terrible design.
Air exchangers at best average temperature of incoming / outgoing air. This is a hard concept apparently. If you are unsure, follow a molecule of air through the system in and out and remember the same number of molecules are exchanged.
It's only a simple average if the input and output air only mix at one point; mixing along a length instead means the average temperature of input/output changes from the temp of the internal air at the inside end to the temp of the external air at the outside end, so MVHR units can do much better than a simple average.
No, a cross flow (or better yet counter flow) heat exchanger can exchange almost all the heat energy. The incoming air can be heated to nearly the same temperature as the outgoing air. My system heats the incoming air to 18C when it is 20Cinside and 0C outside. The outgoing air exits just above freezing
Always loved these videos. I have just one question though. You always seem to recommend reducing the controls to almost or just one zone per house. I'm not sure how that should work in practice... For the classic house of bedrooms upstairs and living rooms down, what happens with just one zone where you want upstairs to be cooler in the evenings for kids being in bed early but adults remaining up downstairs for hours later... If you don't have localised controls in different parts of the house, aren't you down to the whole house being dictated by the needs of one person or area in the house? Is there a video where you guys discuss how to control the heating across the house and what trv valves / controls and thermostats etc you should have where? I've never come across anything to suggest how you go about delivering control to the customer... I'm looking to upgrade my heating system at some point and really want to get it right but the thought of very little control of the individual rooms scares me! Currently I have tado valves in every room which is wonderful for comfort and control but i get plenty of cycling of my very over specified combi boiler.
You just get used to a comfortable house that is ~20C all over. The UK mentality of zone controls comes from drafty cold houses where any unheated part rapidly cools down. Improve that and zoning becomes pointless and irrelevant. That's as much about airtightness as it is about insulation. We got our 1960s 3-bed down to 1.5 ach (from probably about 10 when we moved in), and fitted MVHR as well as a lot of insulation. We just removed bedroom radiators as we like a cool bedroom. You can still have zone controls on UFH and rads, just be aware that using them reduces system efficiency. Ideally (if you like a cool bedroom) you have bedrooms downstairs as heat rises, but of course most UK houses are not arranged that way.
Great video. Adam mentioned that low loss headers shouldn't be used, in those houses but the Mitsubishi pre-plumbed cylinders, which those houses have, include one. Are Mitsubishi wrong to include it?
It is just a pre plumbed cylinder that is not designed very well. Separation (low loss headers) are almost never needed on jobs that are sub 10kW heat loss, so in this case not a single hosue needs it. It lowers the eiffeincy of those systems.
Tell Adam, that a metre or two of 22mm pipe compared to 28mm makes less than 1% difference in head/heat loss in the overall system, the old Darcy-Weisbach equation or moody diagram will tell you that sharp bends are the main issue - Use the analogy in the video of driving a car, motorway / dual carriage way to a mountain bendy road.
his point was that If they really thought it was a 11kW heat loss 22mm pipework had no place there at all, as pressure loss would have been 1600pa per meter, and velocity over 1.5m/s - but because the heat loss is much less they got it right by accident
@@UrbanPlumbers Apologies! - It wouldn't suprise me that with that sort of (very low) heat losses, does one actually need a heat pump? - as the exchange heat between the water tank & CH circuit would suffice - I'm thinking here of cheap overnight direct immersion heating here (Mixergy?) : I'm thinking here of a small heating element @ (say) 200W running 24/7 into the HW tank - or these 150w Hybrid Radiator Heating Elements?
I guessed right around 3kw loss as my 4 bed detached with less insulation (new normal build 2015) had 5-6kw heat loss… So frustrating that can’t be installed properly from the beginning especially when they are installing them in a much complicated and worst way (and more expensive for them too!!), and new houses still having microbore popping and gas boilers!! 😢
Sizing hasn't changed much from the old days. An old-timer explained to me their old-timey method: stand at the street; hold your hand up "stop sign"; count how many fingers it takes to cover the house. That's how many tons of A/C is needed.
Do not you get more efficiency if you place lets say 500liter buffer for system? Which could take heat from pump on its maximum efficincy power and then shut off, and just use stored heat for floors?
The developer and original installers should be named and shamed, they absolutely butchered the heat pump installs on this brand new development.
Yeah. Szymon and Adam are way too nice. And the problem is that $people can't avoid outfits like this if they don't know the names. I guess they are hoping that getting these designers to actually learn how to do it right will be more effective in the long run than naming and shaming. But _in the meantime_ people would like to know. Maybe someone on the development will tell us?
Im pretty certain its Alto Energy - they do installs like this with Mitsibushi heat pumps all the time and have been for years.
@@BristolHeatPumps I had alto design for me, did the day course and that, sounded good if I install the commission and take over.
Did the install for a pal developer and now 6 months on we have realised there running shit.
Done this a few times different companies designing and still the same issues. All new builds and expect a much better performance.
Now I can’t trust anyone to do it and doing the knowledge with heat geek myself.
That saying you want something done properly you do it yourself. That’s my mindset now.
@@stixstonesinvestors5413 yep they are shocking, tbf i would say most umbrellas are very poor quality, if only MCS had some backbone eh!
We are a heat geek ourselves and do all our design in house, its really not difficult to do it properly
@@BristolHeatPumps so true. It really needs to be regulated and rules tightened up.
I know a lot gas engineers who think they know it all and just have that mindset of it’s just a unvented system. They don’t take it serious and if they have someone design it and it don’t work, there attitude is I didn’t design it, it’s there thought.
It’s such a challenge out there ain’t it.
I truly believe the way forward is through heat geek. It’s bloody hard for me but im determined to finish this.
Love your apart of it as well. Good to speak to likeminded people
Love these collabs. You guys are great. I have learned so much from all of your videos (both channels) that I am installing my own system. Thanks!
In Poland, we have been using heat pumps for over 10 years without any issues, with 200,000 units sold annually. They perform excellently even at -15°C. In the UK, despite having milder winters and cheaper electricity, you always seem to encounter problems with heat pumps. Additionally, you regard heat pumps and heat recovery systems as something entirely new, it boggles my mind
UK power cost almost triple the Polish price.
I am assuming 500 zlotys ($123) per megawatt-hour (MWh) for the second half of 2024.
When it gets a lot colder than -1, then the air gets very dry and the heat pump will only need to defrost every 2-3 hours. Between 0 and 3 degrees is the worst ambient condition for a heat pump, because the evaporator can freeze shut every 45 minutes to an hour depending on the operating point and this requires very regular defrosts. Therefore heat pumps can deliver more power and efficiency at -2 degrees then at 2 degrees. UK and the Netherlands have the worst possible climate for air source heat pumps, yet they make it work great anyway. The colder climate in Poland can actualy make it work better in some aspects.
Do you have videos from your installations?
@@andrewstafford-jones4291 The price you've quoted is more of a wholesale electricity price, without distribution costs, additional charges and taxes. As of now, polish households pay about $210 per MWh for the first 1500 kWh they consume this year, anything above that cap is in the area of $330-340 per MWh (and since that cap is quite low, anyone with a heat pump basically runs it on the more expensive electricity only). It is expected that as of July, electricity prices for households will be set at around $280, with no consumption caps.
@@andrewstafford-jones4291 oh please.. I'm paying ~0.25p kWh in Surrey, my mom in Warsaw ~1.15zl kWh (0.23p)
Comparing prices to monthly wages, the cost per kWh in the UK is significantly lower.
Absolutely love you 2 have come together and now a 2nd vid highlighting these issues.
You have to be so on the ball with heat pump installs. I know people installing them just following the design from other companies and I have seen an install which joules designed. I went out to see the install which was a pal that did it because the bills were astronomical.
I could see clearly it was so wrong, 12kw on a small 3 bed new build and thermostats absolutely everywhere.
I said to my pal about a lot of concerns but his reply was I just installed what they said it’s not my problem. I was like……. Geez you can’t be like that.
Heat geek is a lifeline for all that wants to do it the right way. It’s so bloody hard but I love that.
Simon you still the best out there, your content is the best, hope u 2 do more together and bring more light to this industry.
Please keep them coming 👊🏻👊🏻
As a retired heating engineer from uk, i am not surprised at all by what you found, it is the usual situation of designers who dont understand the physics,installers who just follow drawings and may realise its not right but dont get listened too or dont care. And finally commissioning of the system, done by agents who probably dont understand how to set it up,or cant because the installation is wrong. THEN NOBODY IS INTERESTED BECAUSE OF THE MONEY NEEDED TO PUT IT RIGHT.
Another great video. You two make a great team.
Really sad to see that new builds built to a high standard are being let down by shocking heating installations.
Can't imagine what it'll be like once heat pumps are mandatory for all new builds; 2025 in England if im not mistaken.
When an oversized heat pump gets installed for an old leaky retrofit, you can kind of understand why the installers go extra careful even if you know that a proper heat loss calculation is the solution. But with new builds it is inexcusable to get it wrong.
There should be some penalty for the builders.
Blimey. That was pretty scary tbh. For those of us thinking about heat pumps, it's sobering to see "experienced" installers making such a botch of it on a new build property which should be easier than a retrofit. Caveat emptor doesn't even begin to cut it.
Keep up the good work with these videos, really hoping that they can help drive some positive change.
Great video. Many of the ASHP manufacturers have a standard design or schematic that the installers have to follow to maintain warranties and provide sign-off to apply for RHI. For example, the Nibe schematic includes a heat buffer and my installer would not deviate from the design. I'm about to do another new build install and I'm faced with the same for an Ecodan system. Does Heat Geek have a schematic that shows best practices? Or a design listing best-in-class components. Are all of the manufacturer's schematics wrong? I'd love to see a video taking apart what's wrong with each manufacturer's design and showing a drawing of how it's done correctly rather than looking at homeowners' plant rooms, it's too difficult to see what's wrong. Fantastic job guys, I've been following your videos separately so nice to see you working together
It's down to the installers to specify equirement from manufacturers who care about this stuff. Bear in mind that a buffer might have been necessary in your property due to system volume. A buffer isn't automatically wrong, but they are often included when they aren't necessary, or where a small change might eliminate them.
Love to see your work. We are already 13 years telling clients not to do zoning, and we don't use buffer tanks. Use them only on very big systems where heat pump must have very high flow. Nice work, guys. I always enjoy watching you.
I love these videos, explaining how simple it can be and the big part is heating the whole structure as one. It is crazy how this was done to every house.
Since learning about heating, with the help of your excellent channel, i've come to the conclusion that it's not just the topic of heat pumps, or even heating in general - house builders for the most part, especially mass market ones, will absolutely do the bare minimum to (barely) meet the regulations. I am sure there are exceptions but most builders just want to smash houses out for maximum profit. I moved into a new build recently and a weather comp sensor was mounted to the outside wall, but not actually wired into the boiler. The sensor was only there so that it could (at a visual inspection level) meet the Boiler Plus regs. Of course, it's a bottom of the barrel combi boiler with a massive minimum modulation, so it cycles constantly, highly inefficient and will probably fail prematurely (at least then I can replace it with a properly sized unit). Radiators are barely big enough for the heat loss, certainly not suitable for low thermal design temperatures. I think the regs changed again recently so that more effort has to be taken to design for lower flow temps ... but im sure the developers will manage to avoid spending too much money on that ... rant over.
I didn't get the impression that these builders were doing the bare minimum to be honest. It seems like they just aren't aware of the best practices when installing heat pumps. They could probably increase their profit by installing lower output heat pumps, a single circulating pump, and not bothering with buffers, zones, e.t.c. Most people probably wouldn't even consider these things when buying a house so I doubt they would expect to pay more for them.
Something that seems like madness to me is I've noticed a lot of new builds have high levels of insulation and air tightness, but then they just core 4 inch diameter holes in every room and fit hit and miss vents. At least this house has MVHR. Retrofitting MVHR is not worth it in most cases so most people will just have to live with that. If the builders can still hit the desired building energy rating without MVHR then it is easy to see why that is happening.
Also according to the video from UK radiators some sellers are not using the accredited verified heat outputs and quoting much higher outputs for their rads. If you are putting in radiators and heat emitters and they are not outputting enough heat you’re going to get issues. The industry as a whole needs not make sure there is top to bottom regulation and really heavy financially punitive fines if they get it wrong.
It's not just that most house-builders do the bare minimum, it's that they have been lobbying government for decades to keep those standards low. We should have had better building regs 20 years ago - the issue has been well-understood for that long, but the housebuilders keep whispering on govts ear 'if you make us build decent housing it will be 'too expensive' and we won't build so many'. It's not actually more expensive of course, for the householder. You save a lot more on energy costs over the building lifetime than it costs to build a passivehouse _and_ you get much more comfortable, less-allergic, quieter housing. And in places where they legislated for it (e.g Brussels from 2017), it hasn't actually cost any extra. Once it's standard a well-insulated airtight building (with a much smaller, cheaper, simpler, heating system) costs the same to build as a crappy one with a big heating system.
@xxwookey 👏
Maybe it's the Englishman house buyers? Just Google: 'false chimneys' - we have a house building program where fake chimneys get glued onto new houses where there could be solar panels!!! This year a new estate went up in our town where half the houses have pretend chimneys. Fake period features sell houses - not insulation or MVHR.
I'm not a professional but I can clearly see the logic here. All experienced contractors are doing the same thing they did since they ware installing the gas boilers which have higer starting temperature which is okay but at least there should be a new name for the Heat Pump installation and some guidelines when installing it. Should this be a part of a manufacturers manual🤔
As always thank you for your videos. Cheers 🍻
The difference is, poor quality boiler installations for the most part work, they are just inefficient. Poor quality heat pump installs, in the worst instances, do not work at all. And all costing 10x the price of an equivalent gas boiler. It's been a long time coming for all these poorly technically educated installers to get caught out!
Well, they work but they’re just outputting way too high witch causes them to short cycle which doesn’t work for an heat pump, where a gas boiler can vary gas level down to 1 out of 16 levels
From what I gathered watching these videos, most boiler installations in the UK are awfully inefficient as well.
Is this an estate where everyone is a thermo engineer 😂 I love they are all onboard with it. Hope the installer gets the message to fix the mess
The builders are Trivselhus and the largest houses on that development are nearly a £1m so that performance is pretty outragious considering the claims they make, perhaps a class action is required.
@@tonydaddario4706 a court action should be a shoe in
@@tonydaddario4706 On the contrary, I suspect these systems were deliberately over engineered to avoid possibility of complaints of poor heating from demanding wealthy customers. Some people can be very unreasonable, and we all suffer from people covering themselves as a result.
People in other countries besides the us are much more in tune with what a heat pump is. It's mainly the us that is ignorant enough not to learn it.
@@FlyinghookHeat pumps are quite common in the USA - mainly the air-to-air variety. But in the UK they seem to be considered new unproven technology. Boggles the mind.
Great video as usual, with some thought provoking stuff. Mind boggling that, on the face of it, a develeper has gone out with the best of intentions, and produced beautiful houses, but still got it so badly wrong. A couple of things immediately spring to mind....... 1. We need a list of pertinent questions that buyers of such houses need to be asking before they sign. 2. You hint that they are a large well known outfit but you don't name them. How does the unsuspecting public know if they never get called out?!?
It’s a pretty safe bet to avoid all large outfits
@@UrbanPlumbersAhh, interesting. I'm considering getting a heat pump installed because I qualify for ECO4.
Ohhh - those are almost guaranteed to have an atrocious install
@@UrbanPlumbers oh!
Great video as per usual! The larger point is why is it even legal for installers to be doing this with limited customer comeback? How many billions are the government wasting because of inefficient installs? Imagine the needless load this will put on the grid at a national level vs. if we had well-installed heat pumps? It's really sad to see.
This is a fantastic example of installers not understanding the technology and making things needlessly complicated.
- More expensive to install due to the excessive sizing & extra, redundant parts
- More expensive to run
- More errors (some of which balance out, but many of which compound things)
- More maintenance required due to thrashing/cycling, plus engineers will have to have their wits about them if they want to understand wtf is going on
- More to go wrong in future because of the extra complication
Not sure 'The government' is wasting billions here. It's people buying houses (which could have been cheaper) then spending more moeny to heat them than they should be. So it's individuals/families wasting money (and installers who could do a better job much more cheaply if they actually knew what they were doing).
@@xxwookey regulation is needed, so it is the government's fault imo.
@@defragsbin Sure, the last 20 years of failure to set decent buildings standards has been a huge contributor to the current cost of living crisis and has wasted a great deal of people's money (on expensive heating) and government money on the poor health that poor housing generates. I actually blame mass housebuilders as much as the government - it is they they have been campaigning to keep standards low for decades (and the govt is too innumerate to just ignore them and do the right thing for the populace anyway)
@@xxwookey true, but I believe they also are happy to take their political donations too :(
We have a couple of problems in the UK - old and poorly insulated homes, gas prices are under 1/3 the cost of electricity meaning you need a COP of @ 3.5 to financially breakeven if you move from gas central heating to heat pump. Lastly, and what these guys are championing, our heat engineers are trained mostly in safely installing the gas central heating and not optimising and design of heat pump systems.
We are definitely behind our European neighbours but channels like this are helping.
you don't get 1kWh of heat for 1kWh of gas. average gas boiler efficiency achieved (rather than the badge efficiency) is about 83%. so you only need a SCOP of about 2.5 to break even on running costs at gas costing 1/3 of electricity
They’re not even trained in installing efficient gas systems,
The gas safe qualification is just that and nothing else I’d say 80% of guys are of the “Fit a 40kw combi mate” mentality.
@hufartd yea that’s the reality - most only understand how to install a gas pipe - that’s all there is.
The gas central heating systems in the UK are absolute cack too. A typical gas boiler is big enough to heat more than five houses, and runs much less efficiently because of this- the return flow temperatures end up much too high, and so they don't condense properly.
@BooBaddyBig they never condense in the Uk and they fail on average after 8 years making UK a cash cow for boiler manufacturers and a haven for cowboy combi slingers - couldn’t make it up
Really enjoyed this video Szymon, I am the renewables manager for Alpha.
I would love to invite you down to see our new heat pump and cylinder, I think you will find it refreshing.
Ps. We’re only down the road!
email me please
A great video, thanks. Worth noting that the 11.2kW Ecodan is a power limited 14kW unit, with the same minimum output as the bigger version. Also that Ecodan apparently have a firmware update for excessive cycling that they only install if someone complains. My experience is that the 11kW Ecodan cycles rapidly whenever the heat load goes below about 6kW.
Interesting info, thanks! Would make sense that the 11.2kW and 14 are the same internally just the 14kW has a larger evaporator coil and 2 fans.
Mitsubishi has a big problem with truth when we talk data. The units do not deliver what is on the data book. My 8.5kw does no modulate below 4.5kw when it should go to 3. The energy and cop data displayed on the unit are also completely made up.
@@aymerichousez1005 Not defending Mitsubishi but I think if you were to take away all the supporting hardware and do the testing in a controlled environment, I'm sure you'll get good results that match the book. My 11.2kW is returning about SCOP 4.1 and I think it's just down to running 1 circulator, no hydraulic separation, no 3rd party controls, no TRVs, good emitters, good system balance, no glycol and fairly low flow rates as it's oversized and never needs the full output. Internally these units are 90% the same as the best performing ones from Vaillant, Viessman etc, it's all the pre-plumbed and 3rd party nonsense that drags it all down. And Glycol!
@@Loopyengineeringco I would say that unless you use a 3rd party monitor, you don't know what your cop is. I was at first impressed with the COp shown on my ecodan but when I started to monitor temperature and electrical power independently, I realized that these values can't be trusted. The temperatures are rounded and the power is corrected somehow to makes things looks good.
Whatever they claim from test conditions, the competition performs better. I don't believe that these units are all the same. A Vaillant 7kw weight 190kg, a Mitsubishi 8.5kW is barely 100kg...
@@aymerichousez1005 Yeah definitely don't trust the estimates, I'm using a ultrasonic flow meter (ofgem supplied calibrated unit as part of the MMSP package) and 3rd party CT on the consumer unit to do the calculations. I think you're comparing different chassis sizes - the twin fan ones are naturally heavier. But like for like, you're right in that there's still a bit of difference. Vaillant use piston compressors vs scroll compressors on the Mitsubishi, maybe they have more ballast for damping, or thicker casings? Not sure! The Mitsubishi is definitely a lower quality product though for sure, although I do like the controls, AA mode is really good, external API and hackability etc
Definitely want to know how cop changed.
Same
Run it at a constant 20 deg over a winter and you get the real heat loss. UK builds have missing insulation, air leaks so I wouldn’t ever trust a drawing.
Good work boys... the whole point is that these things should be simple to fit...
passive house spec is 10w/m2 peak load. So 2kw. Worth mentioning that passive house on big developments with simple thermal geometry it only adds 2-5% onto the costs over building code.
That is nonsense because we can't even build to "code" properly so passive house would just go even more wrong.
@@Swwils There could be an argument that a better designed house would be easier to construct correctly. Dense packed insulation between double stud walls, for instance. But the UK is attached to certain ways of building (brick leaf, insulation, concrete block, dot and dabbed plasterboard).
@@asabriggs6426 that's hilarious
@@asabriggs6426 my house isn't built like that, so not really?
@@Swwils Research on real PH builds has found that they actually have a very good record of meeting their design specs, unlike most UK mass-build houses. Because you actually have to pass a fairly stringent airtightness test, and design out a lot of the stuff that brings houses down (thermal bridges, thermal bypass), it's actually _easier_ to build it so it works like it was designed. Said researach was published in passivehouseplus magazine a couple of years ago.
THANK YOU! I am commissioning an underfloor heating system right now. I thought it was a bit overengineered and you've confirmed it. I'm going to remove 3 thermostats, 4 actuators and most of the wiring centre :)
I've heard that the Manual J calculation used in the US for calculating heat gain/loss is overly conservative to begin with, then installers pick a higher summer temperature and lower winter temperature to reduce callbacks, and then pick the next bigger size heat/cooling. This produces oversized units which are inefficient during spring and fall.
But what was surprising to me was that unit sizing didn't seem to be done at all before designing the heating system. In most places in the US, it's not possible to get a building permit before sizing the HVAC, and you can't size the HVAC until the windows are selected so the U-values are known, along with insulation and air leakage targets, validated with a blower door test.
The other surprise is that I didn't hear a dehumidifier mentioned. Perhaps that's not a big problem without a cooling cycle, but things like showers can throw a lot of humidity into the air, and with a passive house, a typical bath fan will depressurize the house, and not do much to actually exhaust the humidity. The ERV can help, but only if the bathroom fans are instead the source of the ERV exhaust air.
For anyone considering a heat pump, do your homework extensively. I recently got a heat pump installed and I pretty much knew the size of unit I needed before the installler came around. Micheal Podesta’s channel is a good place to start.
yes - Michael is very good. Buying a heat pump requires customers do the homework.
Don't fit North of Manchester..the ambient temperature is way too low plus winters are long and very cold...have loads of experience with this..@@UrbanPlumbers
Interesting film, as always.
This really underlines the problems with everything UK, too many people involved with each stage thereby each one sidesteps responsibility, but all of them wanting ‘a cut’ . Too many vested interests for it to change.
Until we get some proper standards that are strictly enforced and organised/accountable, we’ll never improve.
If the developers had to pay the customer the excess that the poor install was costing the customer, they would soon change.
Amazing video chaps, great job! Really getting to the crux of the problem within this industry. So called 'experts' throwing this nonsense in, thinking they are doing the right thing. Most of whats installed in these houses is just not needed. KISS! As always the haters will blame the heat pump, when in fact its just lazy 'copy and paste' designs from home to home using the 'thats what we've always done' method of system design. The only people who suffer in all of this are the poor homeowners who have to live with a poor system and pay crazy money for their comfort. Manufacturers are also to blame for producing this nonsense that does nothing for good efficiency. One other point to note that I haven't seen mentioned here, is the longevity of the heat pump in this situation, the compressor is likely to fail within 5 years here too, probably just outside of its manufacturers warranty too!
Looks like the developers of that estate have a way to go yet, though still heaps above the others. I'd love it if you guys - Urban Plumbers & Heat Geek et al, - could get in touch with them and help them on the road to doing 'all things heat pump' the informed and Heat Geek way. After all, what is info and training if not to disseminate and inform the masses. . . .
I guess over specifying means more money from the developer (and ultimately customer) for the job. It’s the heat pump equivalent of a 30kw boiler in a 2 bed terraced house.
This model is an 11kw unit, they're marked on their actual output not input. So it's an 11kw heat pump (which should be about ~3kw input). Still this is hugely oversized, should be
@@velianlodestone1249 11kw ecodans modulate to 4kw, it shouldn't be too bad in theory.
@Etacovda63 if it’s 5c outside and the house is zoned it may only need 500watts, so even at min modulation it’s going to be 8x too big
@@UrbanPlumbers yep, so he shouldnt be doing any zoning (and this assumes he wants the entire house at the same temp, of course)
I mean, what, 100L + volumiser to reduce cycling, even with the open zoning... were your calculations at -2c?
Great video. Oversized heat pumps are a problem though some can operate very efficiently at lower power. This is sometime the silent mode or something like that. That does require inverter technology which I would always recommend. Some additional tips: the cover of the terraced house lady should be removed. The air should flow unrestricted through the outside unit. Installing the outside unit low is actually not good. It has a much easier time circulating air if it is slightly raised. Especially in an area with many walls nearby. On cold nights with very little wind you will get recirculating of cold air back to the outside unit. This makes the unit operate as if it is noticeable colder. You want as much warm ambient air to be drawn in. If two rows of houses with backyards facing each other all have heat pumps they will cause local cooling. Cold air stays put. With AC the out out is hot air which will always escape upwards. COP goes down if the inlet air cools. If there is a small amount of recirculating air it will be a vicious circle. Thanks!
Oh dear, what a shame. A new build should be a perfect opportunity to get a heat pump installed correctly. Hopefully the developer will learn from this mistake, although they were probably just following manufacturers schematics for the hydraulic setup. On the plus side it's great to see heatpumps being installed in new builds, even with a disastrous cop of 2, they are still lower carbon than a gas boiler!
Pretty disappointing when you buy a high end home for a premium over standard new build to have such a poor set up. Manufacturers are at fault here too - some pre plumbed “fits all” system are awful and also more expensive - more education needed for manus and installers but also for developers, so they can chose batter subbies
@@UrbanPlumbers totally agree 👍
In Germany, heat pumps got magically cheaper after state subsidies have decreased. However, pumps were hard to get because everyone wanted to get a gas heating before they were allegedly not allowed anymore. We were trying to work with a local company that only worked in the heat pump business for over 20 years now and had a pretty good reputation. Unfortunately, they couldn't keep up with the demand - became rude and unreliable; google rating dropped vom 4.x to now 2.3.
We're still looking for someone and they all ask around the same amount: 500-1000 Euro above the state funding limit, flat. At one company, you would sign a contract first and then they take a look at your situation.
This is the case with all "new" technologies that have government funding, the price charged by approved installers becomes the open market price plus the government grant rather than minus the grant. It happened with solar panels and EVs in the UK, and now it's the same with heat pumps.
@@garysmith5025 We are now signing a contract with a company that seems competent but is located 300 km away from us. Let's see how they fulfill their service contract...
Great video for a prospective heat pump purchaser such as myself!
Oversizing is bigger problem than undersizing. Of course, you cannot go too low but for such a new building with very heat loss it is crucial to not oversize the unit.
The main problem is minimum modulation on 90% of the year which is usually above heat loss if the case is like you explained here.
It's almost impossible not to oversize the unit because you can't actually buy 2 and 3kW heat pumps yet. (fx:checks) Actually I see Vaillant have a 3.5kW ASHP now (and the old 3kW Geotherm).
@@xxwookey Panasonic has 3 kW without capacity loss down to -7 C
@@HVACEducationHub OK. Good to know. And of course the Air-Air models go lower power too.
Long ago, I did oil heat work here in the US. After hearing your description of the house, my first thought was 3.6KW or 3 ton as we would call it. Most installers over here would probably bump it up to 3.5 ton to avoid complaints figuring the customers won't notice the lower efficiency. 11KW (9 ton)???? Wow.
If it's passivhaus equivalent it's going to be 2 to 3 kw max.with mvhr id be surprised if the heat pump needs to run at all!
In the UK, you'd expect it to have to run in three coldest months for heating, but for the rest of the time, it would only be needed for heating domestic hot water. (The heat loss from the humans, electrical devices and DHW storage and pipe work would keep the house warm the rest of the time)
Oh lord. You should see what they do over here in the US. They even talk about "heat pumps" like they're some new technology that the rest of the world hasn't had for 10+ years. Over here they regularly oversize heating by 4x or more .. nobody even does load calculations
I have underfloor heating in my kitchen and it has two zones controlled independently. UFH uses radiated heat so there is a very good reason to zone it. If you are standing aound a hot oven and active you might want your UFH to work at a lower temperature. You can do this with floor sensors or room stats to shut off zones . Over in the dining area where we also have some seats to relax and watch the television it is nice to have a slightly warmer temperature, Using your open zone method doesn't allow for this. The fact that a heat pump can't cope with this setup is a limitation of the technology.
Is your set up high temp though?
@@UrbanPlumbers As it's Roger, I think we can guess the answer to that question. 😂
You guys seem to actually understand how things work , unlike most plumbers. Please enlighten me on one topic. Ive installed in my house on ground floor two vertical designer radiators upside down, and connected them on the top. It was way easier to run the pipes from the ceilling down. After doing that, I've asked on few plumbing forums and Facebook groops if I've done right, or i should expect troubles. Most plumbers advised that there's no chance that it can work, for various reasons. Now, after 3 winters, I'm happy to report that the system works absolutely flawlessly. So im asking you, how come no plumber could see that the system might work, and why I could see that it should work, even if im no plumber at all.
Thanks
Passive house with recuperator should be around 20-22 w/m^2 so 190 sq m should be around 3.8 - 4.2 kw max.
and then you will not have any choice to get those - even worse: the smaller houses will have an even lower demand which the modulation can barely cover except turning the compressor on and off and cycle
Isn't heat loss dependent on outside temperature?
Where do you get 20-22? All the documentation I can find says ≤ 10W/m2
passipedia.org/basics/building_physics_-_basics/heating_load
www.passivhaustrust.org.uk/UserFiles/File/PH%20Intro%20Guide%20update%202013.pdf
@@VanyaYani Yep, they needed to give us a design temperatures. Odd no one has mentioned this. 😕
Wow, just one of those heat pumps could heat 3 homes in theory.
Not a bad idea at all.
The systems apparently have enough zones to do it too!
The major sticking point would be billing.
Tbh they probably could just have put a tiny reversible air conditioner into the ventilation system and just not do all the plumbing.
When I see a new development where the houses feature heat pumps, it makes me less inclined to purchase as I have little confidence, they will have correctly sized all the components. The same goes for the token couple of solar panels some developers are installing just to tick a box. Really pleased with the Vaillant ASHP system installed by Libtek (Alex is one of your Heat Geeks) in our current home. Next home may have to be a self-build or another home with a gas boiler that needs replacing with a Heat Geek installed heat pump.
Yes Libtek are good!
It's worse than you think. I know of two passif home builds just completed. Both have heat recovery air systems. The heat pump installation is by different companies. Both heat pumps are large. What you would calculate for a gas boiler perhaps. I asked the home owners if heat loss calculation on the new builds answer. Don't know. One home just running temperature set at 45c. He already complained to me about the high electricity monthly cost. The worry is these companies are using these new passive homes to get more work..And messing up the insulation
I came from a geothermal heatpump background started almost 20 years ago open circuit large pipe low temp system simple avoiding distortion accuracy when sizing exc...was actually easy then as general public knew nothing so could do as you pleased nowadays public are difficult want and expect it to be zoned everywhere if you don't supply what they want you don't get the job they think your the hack...
Also Installing well is only half the story very few people can diagnose and repair any kind of heatpump when they get older few years pass quickly. Also manufacturers charge too much for parts older machines tend to become economic rightoffs once 7 or 8 years old too chancy to risk expensive repair... manufacturers need to be tacked on this and shamed talking of lowering carbon and then setting people up with esentialy a disposable heating appliance....
This video is revealing 2 problems:
- the lack of competency of some system designers
- the false data advertise by some HP manufacturers, namely Mitsubishi. You cant design right if the manufacturer does not give you the right data. These issues on Ecodan are so recurring, Mitsubishi is just waiting for a consumer action class against them...
Government should act and make sure that what you get is what is advertised.
what issues with ecodan are you talking about?
What's the issue with Mitsubishi? I have an old R410A one, so I'm interested in what data you think is false.
@@jeffhenderson9595 that's called consumer protection and fair competition. I though that what I was paying tax for!
2kw thermal loss max for the house. you will be looking at 500watt electrical consummation of big 8-to-10kw heatpump will be cycling. cop around 3.2 because of no losses
The "Passiv" part in Passivhaus was meant to mean that no (or little) active heating or cooling is required by means of thermal insulation, ventilation with heat recovery and proper use of solar gain and shading. It seems to me that these houses don't need hydronic heating at all. A modest floor standing AC unit in the open plan space should suffice. That's how these scandinavian houses were designed. The MVHR takes care of equalizing the temperature throughout the house. This way you save space, you save on installation and you get rid of those radiators upstairs.
It's as if the architect did not feel responsible or the builder did not look at the plans.
Indeed. So are they actually PH, because that doesn't fit all that well with the ~3kW heating load Adam and Szimon calculated. They were presumably not accounting for solar gain the way PHPP does.
I live in a new build with a primary energy use of about 27 kWh/m2. We have a 700W MVHR combined combined heatpump and MVHR and backup direct heating which is off 90% of the time in winter. The biggest compalin I have is that the system isn't powerful enough to fight the solar gains in the summer, which means you have to open the windows (and I'd rather not since I'm allergic). I believe that new builds should have external shutters to fight off solar gains in the summer which can'talways be easily retrofit. In short, solar gains are more important with very energy efficient homes. you can't simply create an airtight and well insulated box. You need to take shading very seriously too.
@@Takethis42340 Yes, absolutely. Overhangs and awnings are such simple and effective pieces of technology that have been around for centuries, but seem to be forgotten in some countries. A well-placed deciduous tree might also do the job.
Question on the SCOP figures for a super insulated house like these. Would it be lower overall as the system should spend more time on heating the hot water rather than heating the house? Just thinking that it's usually the heating cycle that gets the best COP vs HW so does it skew the numbers a little bit? I would have assumed that they would be in the 5+ figures for SCOP but if there is little heat demand this would drag the average down.
Yes, that is likely. In a house at PH level hot water load can be quite similar to space heating load. It might even be higher. And COP is typically lower on DHW than space heating, so you are correct. But it's a slightly lower SCOP on a much lower total heat/energy load, so it's still all good.
This is a sad indictment of some of the profession that this standard of workmanship can occur at all ?
"The more experienced they are the less likely they are to be good "! What a terrible shame. The experienced people in the industry should have a head start and be therefore be better ?
With all the bureaucracy and planning that is meant to be done prior to the installation, how does this happen ?
Perhaps a "Gas Safe" model should/could be ado[ted where a person completing the work automatically becomes responsible for it in the future ? Should there be issues, a body mediates between the house holder and the installer has to correct those installations ?
Good work and diplomacy (as always) from the Adam and Syzmon from Heat Geek and Urban.
I do confirm what Adam says, for my country. Here in Belgium the old chaps', in the trade for 40 years, are totally unable to design a system. They just eyeball it and reproduce what they have learned 40 years ago. Your old (atmospheric high-temperature) gas boiler was 25 kW ? "I'll put you a 30 kW so you're sure you won't be cold in the winter." And the said new boiler is a condensation gas boiler, triggered by a stupid on/off thermostat, barely modulating its power, almost never condensating because the flow temp is set on 75°C, and the thing breaks down after 4 years because it cycles 3500 times a year... The owner did invest into insulation and eventually the house had a heat loss of 4 kW. And that happens ALL THE TIME with the old' chaps, the "very experienced" ones. The young boys who learned to *effectively*¨apply the EN 12831 standard and *really* use the method, they do a great job.
I've been training to design heating systems and in the room there were two old' chaps which were there because, they said, they didn't understand anymore why the new boilers fail and the suppliers told them repeatedly to get a training to learn to design. The others trainees were design engineers from design companies which were asked by their bosses to review their design methodologies to get less failing installations and less unhappy customers, and make the company ready for the heat pump revolution.
This system does seem terribly complicated! Obviously you've got to work with what's there already, but if starting from scratch in designing a building with MVHR, would it make sense to look at air-to-air heat pumps to avoid lots of plumbing (I'm not an expert)?
As an engineer I approve of this message. Simpler is always better and more reliable. I am surprised the middle townhouse has the same big heat-pump. That's just silly.
They could only get a good deal on 10 of the same size?
Can someone please say who is the installer? Is it British gas? Is it octopus? I know you want to be polite but people need to know who to avoid!
Next time maybe
Both those companies sub-contract, so you can't generalise. But they are installing for very low costs, so are driving down standards.
How have they solved the outdoor heat pump drainage and ice sheet in the winter being sat on the floor?
Unfortunately, in our litigious blame culture, naming the developer & installer is more likely to generate legal action instead of a cry for help and support.
NL different country same problems.
Keep up the excellent video;s
Thanks guys
Excellent presentation as always , these are all aspects you have talked about before but this time all in one place , I hope you have the chances to re fit some of these system so we can see the results
Very interesting. Seems quite complicated for the consumer to know whats right or wrong.
Based on watching all your videos - between 3 and 4 kw
Keep up the good work - my Brother has a ground source heat pump in Poznan which works fine 😉
After watching Technology Connections about heat pumps, I thought around 4 kW.
Ive installed one of those chinese 18kw pool heat pumps all in ones...just had to pull and connect two pipes to my old heating furnace. A fraction of the cost and free install since i did it myself ( gas is already built in). So far it works great, even when it was -10c this winter.
Why am I enjoying these car crash ASHP post-mortem videos so much!! These poor, innocent home owners have my sympathy. No heat loss calc, oversized unit, basic plumbing mistakes, over engineered UFH, the list is always the same. Not sure if I would want the ASHP so close to the ground, I would be surprised if the manufacturer doesn’t specify at least 200mm clearance. Also not too happy about the casual attitude to the ACH (air changes per hour) guesstimate. Need a blower door test or at least the as-built SAP documents. The MVHR install looked a bit ropey and judging by the ASHP install, probably also needs to be reviewed. The problem with all this is there is no reasonably priced solution to remedy all this. Other than a new ASHP the right size, what can they do?
Video on improving those houses coming later this year
@@UrbanPlumbers One solution would be for the residents to share heat pumps! Keep the 11kW ASHP and run three homes from it.
@tlangdon12 or 5 🤣
A bit of DIY is a reasonably-priced solution. What's really annoying is that all the grant schemes explicitly exclude homeowners so after you've worked out how to do things properly by taking an interest in channels like this and other fora, and worked out that you can a better job for half the money, you are excluded from incentives. They are trying to keep the cowboys out with these schemes, but as we observe it doesn't really work very well. There is also a strong tendency in government to _actually_ only care about the job-creation part, not the _outcome_ of better, lower carbon housing, which could be provided dramatically more cheaply if we let people help themselves.
I DIYed my MVHR for example. It cost about £1300 total for a 3-bed detached (and 9-days in the landing cupboard and loft over Xmas cutting tiresome spiral pipe :-), oh and quite some time making a nice 1st-principles design spreadsheet). Plenty of people could fit their own MVHR and would make a neat job of it. It's not rocket science, and even the design is easy if you use a manifold system. ua-cam.com/video/OVcvk9Wnyw4/v-deo.html
Absolutely shocking. If the installer is MCS certified, simply report this estate to MCS and let them take action. If MCS won't, proves that their 'monopoly' is a sham and no proof of competence. I'm a fan of Urban and Heat Geek - intelligent thinking from first principles, although it's all quite simple really. I'm a professional engineer, so reluctant to join MCS, but not allowed to access BUS without doing so. I know someone getting a HP under the HUG scheme which is PAS2035 based. Five companies involved and not clear who is responsible for anything, so will be interesting to see what problems that throws up.
There is no requirement for mcs certification in this scenario. No grant money to claim back .
@@persona250 Agreed, but the boys tell us this was a large installer, so would expect them to have MCS so they can pick up other work. That aside architects are seen as competent professionals by PAS2035, so why would they specify a badly designed system, or contract out same? We seem to be supporting HG's comment that a challenging mind is better than an experienced mind :-)
Great video. My 11.2kW is on a 6kW heat loss property, and that's already oversized 😂 adding volume & load really helps, open loop everything. Also weirdly, the firmware on Auto Adaptive allows a lower modulation than on WC, mine runs down to about 1000w input watts.
Go on, who's the installer?
Are you serious? You get lower modulation with the auto adaptive than with the WC? Every time I tried the AA, it was running the temperature so high that I thought there was no point. The general feeling I had when talking to people on FB groups was that the scop on AA was very poor.
@@aymerichousez1005 Yeah, the trick is in getting it to 'learn' correctly which can be difficult to do. AA is basically extra smart WC, so using the wireless sensor for feedback it will build it's own flow vs outdoor temp curve (internally, not accessible to the user). But to get it to build this curve you need the wireless sensor/stat in a good place and as open loop as possible, rads, underfloor, everything on max flow and this isn't documented very well, so most people give up when they see the system going full out. It will massively overshoot to start with, then on subsequent runs it will use less and less compressor to achieve the same internal temp but with longer runs at lower flow temps. Once it settles after a few days, I found it generally allows the compressor to run slightly slower than on WC, and for longer periods. WC also seems to have a massive overshoot to begin with, which AA mode doesn't exhibit. I did question Mitsubishi about this but they're not interested. I think a lot of development went into the AA side of the firmware and less for WC. AA is a closed loop control system with feedback, WC is simple open loop
@@Loopyengineeringco Interesting that Mitsubushi were not interested. I think this happens when the local support office feels that they cannot influence the engineers who actually write the software. It's actually a very common attitude in the UK.
Great video. Would love to see a follow up video if you end up going back to fix any of them and the following results.
that is the idea. We are tyring to get manufacturers on board to help with the cost of putting this right.
@@UrbanPlumbers What is the smallest a2w heat pump you can buy??
Around 4kW, but there are exhaust air units that can be below 3kW
I can't see how you'd do a follow up video this year - there's no way the heating should be needed before November at the earliest. Even in winter the occupants, TV, fridge, lighting, phone chargers etc should be enough to keep the house warm.
@@UrbanPlumbersCould one of these exhaust air units be configured for houses with low heat demand ?
Passive house insulation plus MVHR - finger in the air at -2C and 200m2 (similar to my similar bungalow with average insulation and newer windows which is 6.kW according to my calcs) so I reckon 2-3kW heat loss?
The old "when in doubt, overspec" rule gets you into as many holes as it gets you of
😂 true
I spoke to an installer recently who said he always fits 12kW heat pumps. When I replied that it would be much too big for my house he said that it was no problem because it would modulate down to the required output. I didn't take the conversation much further and I intend finding a Heat Geek although there aren't many in my area.
Same guys used to say that about oversized boilers - ohh they just modulate down
@@UrbanPlumbers My 12kw boiler can only modulate down to about 8kw. I only need 5-6kw so it cycles a lot. I've had to replace the ignitor several times since moving in, as it bends out of shape from heating and cooling constantly. Very annoying.
@@UrbanPlumbers Adam said in the film they don't even make heatpumps small enough for that installation (3kw). Wouldn't you have to rely on oversizing and some modulation?
Yeah, I'm getting the same in Ireland. "Oh it modulates"
@@tonydaddario4706 There is a minimum output that the units can run constantly at, any lower demand and it’ll start cycling (i.e. running too high for part of the time, switching off for a while, and repeat). A 5kW unit should be able to run at 3kW, but an 11kW unit like in the video probably just won’t be able to…
14:18 yes, you can get HPs that small and actually smaller. Just not the style you're looking for.
Also note that the minimum capacity for that unit is about. 3.5-5kw. (depends on conditions) it's still too big for the house but not as much as it seems at face value.
I don't know. I'm pretty glad I just have a simple aircon or minisplit (US term?) system; i.e. air-to-air. It's way efficient, simple and indeed cheap. It cools during summer too - which is a nice bonus. The Panasonic I went with has a 5 year warranty too, which is great.
What i find interesting is you always say one pump is enough for entire system. When i was installing Under Floor Heating, they said I needed a manifold and pump per floor? I wanted a central manifold for whole house, was they incorrect?
Most likely yes. There is always 5 times more pumps installed than needed
4kW? - I would love to know how good this number can get with upgrades during extension work to an existing property!
Random question - does having multiple zones (my house has 6 on the ground floor) cause issues with flow balancing?
I figured the system was balanced to create equal flow through all the zones, but if they are turned on/off for various reasons, does this mean that one room may get starved of flow depending on the length of the zones the happen to be on etc?
Excellent video and very thought provoking. Such a shame a premium developer produces these beautiful expensive houses and so utterly fails on the heating system. Thinking outside the box - I think you said 18 properties , so say 60KW heat loss max - maybe they could have put in a ‘district solution and just fit heat meters in each property, maybe splitting the development in two, so two 30KW plants maybe consisting of two cascade units each.
BTW did you tell the young lady the cover on the pump ain’t helping?😉
The cover isnt gonna make it any worse 🤣🤣🤣.
They could cascade 4 x 11 kW units and run the whole estate on that
@@UrbanPlumbers That’s for sure.🤣
Can't believe they installed an 11kW unit in a house with a heat loss of 3kW......I guessed 4 and I'm just an enthusiast.
I've recently had a quote from British Gas for a Vaillant 7kW unit but as they said I needed every radiator replacing it was £8000 with the BUS. Well out of reach for me sadly.
Try Octopus, they say they include radiator changes as park of the quote. I've not used them personally mind you.
That's BS becasue you can usually cascade the exisiting larger radiators to smaller rooms if necessary and don't need all new, but of course they don't want to do that, partly in case a radiator they move fails etc. but mostly because they have a one size fits all approach that assumes replace radiators as required by planned flow temp and heat loss of each room. Find an installer who will work with you to do it more economically.
@@jabberwockytdi8901 Basic radiators are pretty cheap to be fair, a significant part of the cost is labour replacing them, even then, not so much. I just had 6 rads replaced as they were ancient and I didn't want to paint them again, cost me ~£1.2k inc labour; the radiator replacements aren't the cause of an £8000 cost with grant. That's due to other factors, like the existence of a grant pushing up all the costs by... about the amount of the grant!
In a property anything like mine, all the radiators are different sizes, which would make attempting to cascade them a pain due to all the pipe adjustments required, whereas a lot of the radiator upgrades involve same length but increasing the height / depth, much simpler. It's not really that practical a solution to cascade them, and not something you'll ever see any large co wanting to do as a matter of course.
Interesting video, when I install heat pumps I always oversize.
The number of times I get told it is a high efficiency home when clearly it's not.
You can never get more heat out of an undersized HP but you can wind down an oversized heat pump.
Clients complain bitterly about the house is not warm enough but rarely complain about heat pump efficiency.
As well as heat pump suppliers have standard HP sizing and installation requirements.
Go outside those parameters and you are on your own, even if the heat pump is not performing correctly.
Cheers from Oz
If it was me, I would size the unit to exactly to meet 80-95% of optional heating requirements and then an auxiliary electric small boiler for the rear moment the heat pump falls short
I wish we in The Netherlands had guys like you.....❤
I hear Heat Transformers are popular over there?
@@patrickwheeler2646thank you. I looked them up and looks like they are also a big box company. They give an advice based on data given from the customer.
There is no heat loss calculation......
@@patrickwheeler2646 They are somewhat, but education of design or more likely retrofitting is not very good. There's also people who do it themselves with a air to water system and just dump heat in the normal radiator system. Some people will replace wall radiators with fancoils (they have active low noise fans that move the air across the coils)
Dear Szymon and Adam! Amazing video. I am a viewer from the Netherlands and I would really love to do a heat loss calculation myself for my own home. I know all the R/U values etc. How do you do it ? Is the app available for home owners to use? I would love to pay a single fee to do a calculation for my own house.
Curious to know what happens when a heat loss calculation is done, but then later on you find that the developers have left gaps in the insulation, skimped on it in some locations, or not installed cavity insulation properly. This would result in the house not getting quite get to temp when it's really cold. Would you need to remove the smaller heat pump and install a bigger one, if the insulation wouldn't be an easy fix?
You could just suppliment the heat pump with electric heating. The heat pump will be correctly sized for 355 days of the year - for the two weeks of really cold weather, you can just apply some local heat. Fixing the insulation would be the best action, as the losses will continue for the next 100 years or so.
It’s also rare that the heat pump is perfectly sized for the stated heat loss, e.g my heat loss is about 4kW but there are few ASHPs that are rated at 4, most are 5kW. So even if something wasn’t quite right, there’s another 1kW to play with too.
Better to bung up the holes - that's a permanent fix with no ongoing cost or emissions.
Great video love the collaboration with Adam! I'd love to know who the installer was ;) If I'm honest if someone approaches them with constructive feedback and they don't take it on board for future installs they should definitely be named and shamed!
I have a 220m² passive house on 2½ floors (warm loft with 2 rooms on 2nd floor) now 7 years old. Our winter heating load peaks at around 50 kWh / day but the Dec/Jan average is a lot lower at maybe 40 kWh/ day. DHW typically varies between 1½-5 kWh / day depending on use. UFH in a 17t "warmslab" on ground floor. Nothing on upper floors I put in a 3kW inline resistive heater at build, plus a couple of oil filled rads on 1st and 2nd floors to do top-up Dec-Feb. The whole house is run as a single zone at just over 22°C 24×7 (though the 1st floor is typically about 1° cooler). All heating done using minimum price-slots on an Agile ToU tariff. I had initially intended to fit an ASHP after a year or two when the house's thermal performance had been fully characterised. However, as I only spent about £400 p.a. on electricity for space heating, so I can't really justify much more than £4K for the total ASHP install. MCS quotes are a joke: 11kW ASHP and 4-5x my budget. 🙃
But thanks for a very good discussion of the challenges that owners of passive or near passive class owners face.
BTW, my problem isn't with ASHPs ; it's with the UK bureaucratic and regulatory framework. I have a house designed to take a ~ 3kW ASHP for slab heating only; a buffer tank would be entirely redundant. The water flow/return + supply were installed when the house was built, but this approach falls outside permitted development scope as MCS registered installers will only consider a complete replacement which is again totally unnecessary, I am ineligible for a BUS grant and also need full planning permission to install a very simple ASHP solution. Absolute nonsense.
Storage heaters? Ugh.
@@rogerphelps9939 Not sure why the channel owner deleted my response to this; poss because I linked to another UA-camr that did a timelapse of a build like mine to explain the slab construction.. No storage heaters. The entire 17t slab and the internal fabric of the build is inside the thermal envelope and acts as a heat battery. Last Jan, I had a bug on my control S/W after a change on the UFH heating and it was out for a couple of days, because by then we noticed that the house had lost about 1½°C -- enough to notice.
This is what you get if you design for individual components, rather than as a whole system. Having said all this, the difference in running costs at such low heatloss values / operation, will only cost an extra £1 / day in winter to run. i.e. it goes from £1 to £2 a day.
care to explain?
@@normanboyes4983 Adam notes a COP of 4, the current system has a COP of 2, hence from £1 to £2 a day, at 4kw heat loss.
@@EverydayLife621 It makes you wonder if the proposed remedial works will pay back (eg will they swap the unit to avoid cycling?)
@@normanboyes4983 These are super well insulated houses built to higher standards than even the current building regs. They really don't need much heating. The whole idea of a 'passive' house is that the heating demand can be supplied from the waste heat from cooking, lights, hot water and just living in the house. I imagine that they only need to turn on their heating in the middle of winter.
I got a 2.5kwh heatpump on a 265sqm house. triple glaze with thermally broken windows, AND a mechanical ventilation system are the key
Hopefully heat geek help the owners fix the issues
My initial thought is if built to Scandinavian standards, and almost passive house with MVHR would make it ideal for an Exhaust Air Heat Pump, so sub 5kW. Lets go with 3.5kW
At least close enough to not cause any cycling. 🤣
Yes should I’ve been a completely different set up for those houses. Very good guess on the HL
@@UrbanPlumbers But the 3kW heat loss is calculated at what outside temp (-2°C?) which it hasn't been in England for some time, so clearly this house hardly needs any heating at all at the moment. It will be getting enough from the appliances and people inside. Which means the heat pump is probably only doing DHW and for a High Temp ASHP a COP of 2.2 is about right for hot water. If you put a heat pump of any available size into a house that barely needs heating but still requires hot water, you're going to get a poor COP.
@johnhunter4181 scops for heating is 2 and for hot water 2.8 I think - all figures are in the video for all house types. They all have heating scop of around or below 2 and DHW scops of around 2.5
Same story here, in Switzerland., lack of engineering knowledge and possible conflict of interest (it's more profitable to sell an overpowered pump) all work against the customer.
i have the preplumbed cylinder and the filter is already connected to the flow side and pump below for the recirculate to the hotwater heater for cylineder so big error from Mitsubishi.
The whole heat pump roll out is being done like a boiler lift and shift with a few tweaks. My learning from all these videos is that it's a new concept altogether. E.g. run during the day when it's warmer, (over 5C), and have a massive heat store and thermal mass keep you going for some time. E.g. 100 litres of water per meter squared of ground floor area. That's a lot. 10 tons from 21C to 40C is 19* 10*1000*1000*4.2 J or 190MJ, divided by 3,600,000 giving 52kWh.
The fact we don't run dehumidifiers for shower rooms blows my mind. High water vapour content hot air is free heat. The lack of a heat exchanger on the outflow seems ridiculous too. Simply wrapping the cold input around the outflow can reduce hot water requirements significantly, while not affecting peak temperatures available.
A 10 min shower will use around 1.5kwh of electricity. For a 2kw house with 2 people running a heat pump at COP of 3, heating power would be 16kwh/day. Showers would use 3kwh per day. In this conservative situation ~19% of power goes towards showers, and they are doing nothing to mitigate that. It is actually significantly worse than that, because if you are opening a window you are deliberately expelling air without putting it through the heat exchanger, meaning the air that replaces it will be cold and need to get heated.
I know it was a throwaway comment, but the complete lack of work on making showers energy efficient bugs me, because there is a lot of low hanging fruit there.
Very interesting presentation, especially when that system was investigated, and all of the installation faults were highlighted...
Obviously, I'm no expert, and I'm going to take what was said as a statement of fact: so my question is... if all of this is true - does the customer have the right to insist that the installation company comes back and rips it all out and redoes it properly (free of charge, obviously)!
in theory yes - in practice the original installer and specifer lack the skill set to do it right
I see there is interest conflict for original installer, all comments and on neighbours installs, mention extra unnecessary hardware and labor which is good for business but bad for customer.
New installers value good feedback to get new customers via recommendations , while experienced big companies don’t need good personal feedback to keep business running.
Very good point about temperature difference in connected areas, all most impossible.
It's very bad for the customer as they are paying 5% interest on the cost of the bad install for the next 30 years! Plus all the extra fuel!
The only way to improve public confidence is by bringing the building regs (Part-L) up to an adequate standard that protects the consumer. Correct me if I’m wrong, but where does commissioning and provision of information set out that a heat loss calculation is provided? Part-L’s efficiency for heat pumps (Table D) also only refers to efficiency as 250%, but commissioning as set out by section 8.9 appears contrary that it should be in accord with ‘manufacturers instructions and appropriate system design parameters’.
This Govt were so concerned about public perception, that they commissioned Nesta to do a survey of MCS accredited ASHP installs that paid respondents £250 just to complete the survey. So no bias there. It found that over two thirds of even the MCS accredited installs relied on a secondary source of heating, of which around half had installed a wood burner. Nesta thought it not necessary to ask why so many rely on secondary heating.
not my experience - most hosues with heat pump we install or visit do not have secondary heating. Only around 5% have wood burners - that is all.
@@UrbanPlumbers Nesta survey was largest survey in U.K. with 2500 respondents. But really good yours don’t. That’s how it should be.
I know I got asked to do it but on question number 238999 I told them do get lost 🤣🤣🤣
Having been designing a 5 bed Passivhaus for a while, I guessed the heat load would 3kW! I would have liked to have seen more discussion of the impact of domestic water demands on the heat pump size. These properties seem to have been provided with large storage cylinders to allow lower temperature water to be stored.
You are right that DHW can be about the same load as heating once your house is efficient, but unless the heat load is such that the heating is running al 24-hours there should be enough time in the day to heat some hot water as well without actually increasing pump power. I don't think anyone tries to do both at once do they (except maybe Atmos gas boilers)?
How does a bigger cyclinder let you store lower-temp water? The minimum temp for a useful shower/bath doesn't change by cylinder size. It's ~40C/45C respectively. And 10-60l (people vary wildly here).
Do you mean that if you are in danger of using all your hot water in one day then you could raise the temp so less hot water volume gets used by each shower/bath (and more supplied by cold)? That's the same as saying 'your tank needs to be big enough for daily usage'.
Ecodan cylinder needs a separate pump as it heats up the cylinder indirectly using a plate heat exchanger. But you could remove the other pump and run the heating system on 1 pump
those systems have 4 pumps. 1 for the external unit, 1 for DHW, 1 for rads and 1 for UFH. - 2 of them can be easily removed. Those mitubishi cylinders are a terrible design.
@@UrbanPlumbers yes very inefficient
So is it more efficient to be heating every room constantly at lower temperatures as opposed to be turning zoned spaces on when required.
Yes massively more efficient
@@UrbanPlumbers I have rooms that would not require heating all year round and maybe just at Christmas. Would that not be an unnecessary heat loss
No it wouldn’t. It’s usually more efficient and quite often cheaper to keep most houses up to temp with heat pumps.
Air exchangers at best average temperature of incoming / outgoing air. This is a hard concept apparently. If you are unsure, follow a molecule of air through the system in and out and remember the same number of molecules are exchanged.
It's only a simple average if the input and output air only mix at one point; mixing along a length instead means the average temperature of input/output changes from the temp of the internal air at the inside end to the temp of the external air at the outside end, so MVHR units can do much better than a simple average.
No, a cross flow (or better yet counter flow) heat exchanger can exchange almost all the heat energy. The incoming air can be heated to nearly the same temperature as the outgoing air. My system heats the incoming air to 18C when it is 20Cinside and 0C outside. The outgoing air exits just above freezing
Always loved these videos. I have just one question though. You always seem to recommend reducing the controls to almost or just one zone per house. I'm not sure how that should work in practice... For the classic house of bedrooms upstairs and living rooms down, what happens with just one zone where you want upstairs to be cooler in the evenings for kids being in bed early but adults remaining up downstairs for hours later...
If you don't have localised controls in different parts of the house, aren't you down to the whole house being dictated by the needs of one person or area in the house?
Is there a video where you guys discuss how to control the heating across the house and what trv valves / controls and thermostats etc you should have where? I've never come across anything to suggest how you go about delivering control to the customer...
I'm looking to upgrade my heating system at some point and really want to get it right but the thought of very little control of the individual rooms scares me! Currently I have tado valves in every room which is wonderful for comfort and control but i get plenty of cycling of my very over specified combi boiler.
You just get used to a comfortable house that is ~20C all over. The UK mentality of zone controls comes from drafty cold houses where any unheated part rapidly cools down. Improve that and zoning becomes pointless and irrelevant. That's as much about airtightness as it is about insulation. We got our 1960s 3-bed down to 1.5 ach (from probably about 10 when we moved in), and fitted MVHR as well as a lot of insulation.
We just removed bedroom radiators as we like a cool bedroom. You can still have zone controls on UFH and rads, just be aware that using them reduces system efficiency. Ideally (if you like a cool bedroom) you have bedrooms downstairs as heat rises, but of course most UK houses are not arranged that way.
Great video.
Adam mentioned that low loss headers shouldn't be used, in those houses but the Mitsubishi pre-plumbed cylinders, which those houses have, include one. Are Mitsubishi wrong to include it?
It is just a pre plumbed cylinder that is not designed very well. Separation (low loss headers) are almost never needed on jobs that are sub 10kW heat loss, so in this case not a single hosue needs it. It lowers the eiffeincy of those systems.
I'm 5mins in and I'm going with 190m2 x 15W/m2 x 1.1(ventilation) = 3.1kW heat loss.🤔
That's insane. Not even the basic plumbing bits are correct, nevermind the heatpump side of things.
The only two people in the UK that love new builds
Just found this channel.
I would love to see these P&IDs posted so people can learn and copy.
Or do you have a training video?
What’s P&ID?
Tell Adam, that a metre or two of 22mm pipe compared to 28mm makes less than 1% difference in head/heat loss in the overall system, the old Darcy-Weisbach equation or moody diagram will tell you that sharp bends are the main issue - Use the analogy in the video of driving a car, motorway / dual carriage way to a mountain bendy road.
his point was that If they really thought it was a 11kW heat loss 22mm pipework had no place there at all, as pressure loss would have been 1600pa per meter, and velocity over 1.5m/s - but because the heat loss is much less they got it right by accident
@@UrbanPlumbers Apologies! - It wouldn't suprise me that with that sort of (very low) heat losses, does one actually need a heat pump? - as the exchange heat between the water tank & CH circuit would suffice - I'm thinking here of cheap overnight direct immersion heating here (Mixergy?) : I'm thinking here of a small heating element @ (say) 200W running 24/7 into the HW tank - or these 150w Hybrid Radiator Heating Elements?
I guessed right around 3kw loss as my 4 bed detached with less insulation (new normal build 2015) had 5-6kw heat loss…
So frustrating that can’t be installed properly from the beginning especially when they are installing them in a much complicated and worst way (and more expensive for them too!!), and new houses still having microbore popping and gas boilers!! 😢
Sizing hasn't changed much from the old days. An old-timer explained to me their old-timey method: stand at the street; hold your hand up "stop sign"; count how many fingers it takes to cover the house. That's how many tons of A/C is needed.
Do not you get more efficiency if you place lets say 500liter buffer for system? Which could take heat from pump on its maximum efficincy power and then shut off, and just use stored heat for floors?