"Heat pumps don't work in old buildings" - Low Carbon Lifestyle Episode 36

[@TomBray-LowCarbonLifestyle]

What kind of house do you live in? Have you got any insulation, or double glazing? You may well be ready for a heat pump, why don't you look into it?

[@schrodingerscat1863]

What about the £10k-£12k cost of buying and installing it, most people are better off spending the money on upgrading their insulation and staying with their gas boiler. This will actually reduce their carbon footprint rather than increasing burden on electricity grid.

[@TomBray-LowCarbonLifestyle]

@@schrodingerscat1863 hi Paul, it’s a good point, although I’d ask what is most efficient use of money? How much will we reduce emissions with £10-12k? Insulation is fantastic and a no regret action but without a really deep retrofit might just be reducing gas use by 20-30% when a heat pump would reduce emissions linked to heat by 60-70% and will get better as the grid decarbonises. Would definitely encourage spending money on insulation. But we need to make a step change in our emissions too. Not something most of us can afford (I was lucky to be part of a research project) so we need government support to make the change.

[@jukeseyable]

Tom you say in the discription that it costs a little more, looking at the captions on your video, it's around 12 extra, all though this may appear on the face of it a small sum, it's actually a 50% increase over the equivalent gas cost. Additionally with the massive price rises in energy, many people can not afford any increase. You come across as terribly out of touch with the reality of living in Britain ATM. Secondly Government funding is rarely a good thing, it encourages cowboys into making a fast buck with sub standard installs. 3rdly, use of air source is low per head of population ATM, you start stacking streets full of them in urban areas, reducing the amount of latent heat available and coupled with the aforementioned cowboys, just watch that cop drop off a cliff. And finally, it's great that you have switched on to how serious the issues of global warming are, but significant evidence now points to the fact that it is all ready to late, and we have entered run away climate change, no amount of air source heat pumps will change it. Shut the stable door by all means, but the horse has long bolted

[@jukeseyable]

@@TomBray-LowCarbonLifestyle were you part of the government one that set about giving away free heat pumps, out of 70k applications only 13 people went for it. Skill builder did a long vid on this with one of the top folks from Worcestershire Bosch?

[@TomBray-LowCarbonLifestyle]

@@jukeseyable Hi Glyn, you've said a lot here so I will try and go through it bit by bit. You're right, our costs this winter have been about 50% higher than if we had a gas boiler, partly because gas rates are so low, with my new rates as of this week, the equivalent cost would have been 4% higher for the heat pump, but not trying to pull the wool over anyone's eyes, for our house (a victorian terrace in the North East) a heat pump is not cost saving, if we can improve the efficiency slightly it would be saving and we will be working to do that over the next 12 months. I'm sorry I come across as out of touch, I am trying to report our experience and encourage others to do something similar. Not sure what point you are making on government funding, have you never used a road, a school, a doctor, a hospital...? Absurd thing to say! Yes the use of air source heat pumps is low, but by 2028 the government wants to install 600,000 per year. This is the main way we can reduce emissions linked to domestic heat. I am not convinced that heat remaining in the air will be a problem with more heat pumps, feel free to share some calculations / papers on this if you have anything to back that up? What is your suggestion for climate action? Keep emitting at our current rates, watch temperatures run away from us, see crop failure, extreme weather, drought, sea level rise, mass movement of people, risk to billions of lives....? Or do you want to work hard to minimise the risk, keep below 2 degrees (or below 1.5/1.6 degrees) and hope to minimise risk? I agree the horse has bolted, that doesn't mean we can't try to slow it down. Thanks for messaging.

[@optroncordian7863]

So, you make your heating more expensive to reduce your co2 emissions!? You are a hero!!!

[@TomBray-LowCarbonLifestyle]

Hi Optron - thanks for messaging, yes on our old rates I think it was about 30-40% more expensive. On our latest rates since the energy crisis, I think it is more or less the same price. We’ve all got to reduce emissions as soon as possible, so I’m trying to reduce mine and show others what could be done. Hope you found the video helpful / interesting

[@williampatterson3683]

Unsustainable fir the vast moj9rity of citizens. We are in a cost of living crisis a d encouraging vulnerable people to change to a system which costs considerably more to keep warm is morally wrong. People are having to choose between heating and eating with current systems, you are suggesting they now starve AND freeze. I just doesn't make financial sense.

[@lynndollarhide6887]

Good to see a new video from you.

[@TomBray-LowCarbonLifestyle]

Thanks Lynn!

[@lumbarsupport]

Interesting video thanks. I've had an 11.2kW Mitsubishi Ecodan R32 since last June and it has worked brilliantly, keeping us comfortably warm through the coldest winter days and nights at -3degC, with headroom for at least another 4 to 6degC lower than that. Energy consumption is an incredible 70% less than the gas system it replaced. Currently that only transaltes into roughly break even in terms of cost although, as you hinted, that may change if the cost of gas rises faster than electricity. Still a remarkable achievement given the fact that electricity is around 5 x the cost of gas at the moment.

[@TomBray-LowCarbonLifestyle]

Hi Phil, that's fantastic to hear, and breaking even on gas is a great result! I think the fact about energy consumption is a really interesting one, heat pumps are just so much more efficient at using energy, if we ignore costs, they make sense on their own...! And when we think through the impact on our emissions, fantastic!

[@lumbarsupport]

Even more astonishing when you consider the central heating and hot water by itself. In the last full year before heat pump my boiler used 21,000kWh of gas. My total electricity consumption (heat pump not metered unfortunately) is now 7,000kWh, of which 3,000kWh is my domestic (non heating/hot water) usage, so only 4,000kWh of heat pump electricity consumption, i.e. less than 20% of the gas boiler energy consumption. This has easily beaten the estimate the installer gave me of 5,000kWh which was based on full occupancy.

[@rafum5]

''coldest winter days and nights at -3' 😂😂😂

[@matthewbenton1630]

Yep, they can work in old houses. Double glazing throughout and 300mm loft insulation, providing the heat pump is specified and installed correctly. I have a 1900 mid terrace brick house in Bristol. Thanks to GHG I had an 7.5kw Daikin Altherma installed last September. For heating only I reckon I'll end up at 2300kwh electricity used, about 3.3 SCOP for the winter, with me working from home nearly every day. One thing to point out about the EPC is the expected consumption is based on gas, or standard electric resistive heating, so heat pump consumption should be no more than 33% of the EPC figure. My EPC space heating figure is about 10,700kwh, so this winter using 2300kwh electricity is a little bit cheaper than gas, as the energy price caps mean electricity is 4x the price of gas. A good thing about the Daikin Altherma is the android app allows you to vary the flow temp easily, so I set it to 40C on mild days, turn it up to 45 or maybe 48C on the coldest days.Often I change it a couple of times a day to get the best efficiency.

[@TomBray-LowCarbonLifestyle]

Thanks Matthew, all interesting insight! Sounds like we are in a similar house, maybe Durham is a bit cooler than Bristol for some of the year..! SCOP of 3.3 sounds great, and yes, the lower energy demand is brill. We actually have heat and electricity meters connected to our heat pump specifically so can track how it is performing throughout the year, have had it 9 months now and our SCOP is around 2.92 but could maybe get to 3 over the full year...! Ours is set up to follow a weather compensation curve based on external temperature, although I imagine I would do the same if I had access via an app. Thanks for messaging, great to hear of another happy person with a heat pump!

[@manfromdelmonty303]

Hey, similar house style and location, when set to >45 degrees during cold weather, is it running constantly pretty much? Cheers!

[@dpn1604]

So the selling point of a heat pump is... It's more expensive than a gas boiler...

[@TomBray-LowCarbonLifestyle]

Hi DPN, no the selling point is that it reduces emissions and improves comfort and it’s about the same price to run as a gas boiler

[@tonyedwards6369]

An interesting watch and read. I dry lined my four level victorian semi house in multiple occupancy bubblefoil and battened air gaps myself a lot of work but has proved very effective. Simplest is best,all considered has proved correct at 81 :-) Heating we have Baxi balanced flue gas wall heaters no maintenance cost one in my accomodation forty years old pass annual test every year. The two Brittony 2T water heaters for the two kitchens and three bathrooms twelve years old gas use and registered gas fitter costs maintenance significant probably replace with condensing gas water heaters. Old brittony then scrap? no they will sell on ebay cost of electrical safety distancing changes to baths to pass regulations is I guess why they sell as they do not need a powered flue. Living in Vancoouver in late 1970's we had sawdust burning gravity warm air central heating system,lovely pine smell when it did not go out in the middle of the night! some of these the flue accumulated pitch residue and caught fire fortuntely ours did not. Now virgin forest trees in BC are gound up to make wood chips shipped more than ten thousand miles to burn in Yorkshire how can anyone make sense of such nonsense?

[@marcwhite7733]

Fab info, I have a victorian house which is cold and leaky but beautiful. I think an ASHP with thermal PV plus normal PV and battery is the way forward. Thermal would heat my kitchen/hallway, which are always cold, during the spring,summer,autumn and ASHP coupled with a home battery to suck up the solar and off peak lecky.

[@TomBray-LowCarbonLifestyle]

Sorry for slow reply… This sounds brill. As long as everything is sized properly, I’m sure youll be able to get a great system to suit. I tend to try to keep things as simple as possible so avoid multiple different systems, ie ASHP + PV would be plenty. But if you can add in solar thermal, and a battery, that would be amazing, if potentially complicated…!

[@Lewis_Standing]

Loved this Tom, thanks for doing this. I have a similar style house but 3 stories with 50m2 each floor, 3m high ceilings so 450m3. A free heat loss calculation estimates I have 12kw heat loss at design temp. If I fit solid wall insulation for 12 grand that would reduce to 6kw. If I get a QBot in to insulate the suspended floor it would be 5kw. Very much want to do these things. Looking into finance via a green mortgage approach. So I could cut my heat demand by 60% for 16 grand, a heat pump is 2k, a sunamp 1k. Radiator upgrades to raise my COP might be a few thousand too though estimated 7k. With the 5k government grant wre still looking at 20k though. To put in context this is still

[@TomBray-LowCarbonLifestyle]

Really interesting analysis! Have you seen any of the heat geek videos? They have a cheat sheet on heat pump sizing - kzbin.info/www/bejne/Y4etgn-ZisSMoLc - definitely not 100% accurate but helps give some insight. I would say that 12 kW sounds a bit high (ours is 5 kW) But I would say that solid wall insulation could be a really good step, I find myself day dreaming about doing something meaningful like that a bit too much! Qbot is an interesting tool. Have you seen Airex? Might be a cheaper and almost as effective solution www.airex.tech/homeowners We had a mortgage to do up our home through Ecology Building Society, we were really pleased with that and were able to make some significant improvements, wish I had been a little more ambitious with some external wall insulation too. It sounds like you have got a great plan, hope you are able to find a contractor to do a good job, would love to hear all about it if you do take the plunge. Tom

[@gasdive]

Why would you spend 7k on upgrading radiators when you could put in an air to air heat pump for 1k and get a better result?

[@TomBray-LowCarbonLifestyle]

@@gasdive HI Gasdive - I think Lewis was estimating that a cost could be as high as £7k, I would suspect any works would be less than this unless his house was HUGE. I am not convinced an air to air heat pump would be a better result, it might offer heating for a single room, but would be a big job if you were installing units in every room. If you have an example of a system in a house like mine (3 bedroom house in the UK) then I would be thrilled to see it!

[@gasdive]

@@TomBray-LowCarbonLifestyle I'm not in the UK, and it seems that no one in the UK installs air to air, so examples are thin on the ground, and I can't give you one. They're popular in the South Island of New Zealand, which has a similar climate, and very popular in Scandinavian countries that are colder. You can get multi split systems that let you put a head unit in each room, with just one outside unit. More expensive than a single head unit, but cheaper than four separate units. I'm not familiar with UK appliance stores, but some googling around should turn up something.

[@TomBray-LowCarbonLifestyle]

We use them a lot in commercial settings and areas where comfort cooling is needed, but our homes are almost all heated using a wet radiator system

[@plane3775]

Hello there! Really interesting video, thank you, and great to know that it worked and massively reduced your emissions from an older property. I'm interested to know how the financials look now that the energy prices have changed - I'm guessing that the financial argument is now almost as strong as the emissions argument? Thank you!

[@TomBray-LowCarbonLifestyle]

Hi Michael - thanks for the message, I’ve done a couple of videos about the finances, this one - kzbin.info/www/bejne/n5a5daaJlL6Cnbc&si=EnSIkaIECMiOmarE is using the latest price cap figures. I think we will more or less break even compared to a gas boiler. I suspect other homes with better insulation might be able to run a heat pump more efficiently and therefore a bit more cheaply. If coupled with solar panels we start to get some synergy with ‘free’ electricity powering the heat pump some of the time. That’s the ultimate goal!

[@plane3775]

Thank you @Tom Bray! We've just ordered a Mitsubishi 8.5kw heat pump, new rads, 200l cylinder and 5 panel solar system and installation starts in the next fortnight. Going to be interesting! We're a 3bed 1935 semi with cavity insulation, modern loft insulation, and a mix of double glazed and secondary glazing on original windows.... Fingers crossed it's going to work as per the surveyors assessment, reduce our emissions, and not increase our costs too much. Going to be very interesting learning how to use it..... And assuming that constant steady heat is the way to operate it rather than the on off method with our gas boiler.... Wish us luck please!!!!

[@TomBray-LowCarbonLifestyle]

@@plane3775 Fantastic Michael - sounds like a fantastic step! Yes, running for longer hours at a lower flow temperature is key to efficiency, do you know what flow temperature your radiators were sized for, the bigger the better and the lower the flow temperature. Good luck but I am sure you won't need it! Do get in touch if you want to talk anything through Tom

[@gedog77]

This video needs revisiting with the new October gas price.

[@TomBray-LowCarbonLifestyle]

It does, and the video I did this week is now a bit out of date. kzbin.info/www/bejne/mqayg6iDaLmZppY Maybe should have waited a few days...! With the new rates announced today my assumption is that our heat pump will still be around 15% more expensive to run than our old gas boiler, but the gap is closing

[@gedog77]

@@TomBray-LowCarbonLifestyle I’d be interested in scenarios or extrapolations from your current data. If your insulation doesn’t change and the October and January price changes occur what does that do to your monthly figures? And how much insulation is needed to achieve a financial as well as environmental benefit?

[@gedog77]

I also happen to live in a Victorian mid terrace. With incomplete double glazing, a fire place and floating floorboards.

[@TomBray-LowCarbonLifestyle]

Thanks for coming back - if over the next 12 months we use the same amount of electricity for the heat pump (4000 kWh) then at the new electricity price cap rate (51.89 p per kWh) this would cost £2076, which is £173 per month just for heat. I don't have an estimate of what impact certain insulation impacts would have but at £2000 per year, every little helps, if I was able to reduce heat loss, or improve heat pump efficiency by 5% then that is £100, it all adds up. I think we will all need to be looking for those efficiency gains this winter. Some mates bought one of these - www.chimneysheep.co.uk/ - to help reduce chimney draughts

[@gedog77]

@@TomBray-LowCarbonLifestyle thanks for coming back so quickly and with a good suggestion.

[@gasdive]

I don't understand why UK people always install heat pumps as faux gas boilers. Heat pump efficency is very dependent on the temperature gradient. If you pump up from outside air temperature to inside air temperature it's much more efficient than pumping up from outside air temperature to the 50C of a water heater. Plus a simple air to air non ducted heat pump is very cheap (under 1000 UKP), should give you a COP up to 7, and can be installed in a couple of hours with no changes to the fabric of the house.

[@TomBray-LowCarbonLifestyle]

Hi Gasdive, thanks for the comment, in the UK each house tends to have a central heating system with water distributed around a radiator circuit, we do not have many homes that have an air to air heat pump, if we were going to heat our homes in that way we would need a multi-split system or several separate units serving each room, radiators are a subtler way of heating. I would be very surprised if an air to air system had a COP of 7 when it is 0C air temperature outside but you are right, they can give very high efficiencies and should be the solution for some buildings. I doubt you would get one installed for under £1000 though! I would say that our radiator circuit rarely gets up to 50C, but changes temperature based on external temperature, or linked to heat loss from the house, so at -5C it might be 50C, but at +5C it is at 42-43C. Where are you based? How do you heat your home?

[@gasdive]

@@TomBray-LowCarbonLifestyle Hi. I'm based in Australia in a temperate climate. It gets to about -2C here. 3 bedroom uninsulated house. One small Daikin split keeps the whole house warm. I did a bit of a Google around and found a system similar to mine, an Hitachi 5 kW, installed for 990 GBP, but they seem to be much more expensive in the UK as I'd pay that in AUD. "Cooleasy" plus usual UK extensions is the website. A unit that has a COP near 7 is going to be more expensive of course.

[@gasdive]

Oh, I misread. Its 249 pounds to have a tech visit and sign off a self install. That's more than we pay for an install. Getting them to actually install it is like 700 pounds! That's triple what we pay.

[@TomBray-LowCarbonLifestyle]

Although the kit might cost £990 the installation is likely to cost more than that, air-con engineers in the UK need F-gas qualifications to install a system like that, and there aren't many who do domestic installations. I can imagine how attractive an air to air system is when you need cooling in the summer, as I assume you will in Australia. Increasingly, we do in cities in the UK, particularly in the south, but not really needed in homes where I live, and I want to avoid the option as much as possible to reduce the amount of energy used throughout the year. The key metric is seasonal COP, so how does a system perform all year round, 7 might be the maximum COP when you are heating a space with already high external temperatures, but not at -2...?

[@gasdive]

@@TomBray-LowCarbonLifestyle the kit was 750. I thought it was 250 for install, but it's 250 for an inspection. 700 for an install. We also need certified installers, but the price is very different. Both for the units, and the install. I don't know if that's lack of competition in this space, or an attempt to push people toward "boiler" conversions that seem to be much more lucrative for sellers and installers.

[@derekclark7545]

Seams a bit low your cop, best way to get it up is to not go over 45 degs heating water and if you can't do that then increase the radiator size so as you can. also don't start an stop the heating just have a set back temp for when your not there or at night and not lower than 18 degs. Hope its also one big zone for the heating with no thermostatic valves and last I assume its weather compensated control. good luck.

[@TomBray-LowCarbonLifestyle]

Hi Derek, yes I think you’re right, that video was a couple of years ago and we are seeing much higher COPs this year following changing much of the settings you mention in this video. This is my latest video on efficiency this autumn kzbin.info/www/bejne/rnjck6KpZriKa9ksi=yNchVIPduF6Ivl51 And a video last year about the changes I made kzbin.info/www/bejne/pqLSdpadpq2XfLMsi=yKlHrzcWNoYlJLtI Thanks for the advice!

[@simonpeggboard4004]

What are you basing the carbon emission data on, is it the electrical suppliers? Also what temp do you keep your house at and is it underfloor or radiator heating. Sorry if that intelis in other vids.

[@TomBray-LowCarbonLifestyle]

Hi Simon, my day job has a bit of carbon accounting in it, so I tend to use the BEIS conversion factors as best practice for carbon reporting www.gov.uk/government/collections/government-conversion-factors-for-company-reporting But I’m conscious of the regional emissions that national grid ESO reports / MygridGB etc, and that ‘renewable energy suppliers’ are suggesting zero carbon supply… using the BEIS factors seems fair. At our house we have mainly radiators but a small area of underfloor. The flow temperature is based on a weather compensation curve at about 48 degrees at 0C, around 40 at 10C… I have shown the curve on another video but gets a bit lost! It’s the Vaillant controller and they have a standard weather comp set of curves. Ours is currently on 0.75 although was higher on the coldest winter day. Hope that’s helpful?!

[@joewentworth7856]

Wondered how you have got on improving your cop. We have the 7 kw version in a similar house except a bit of ufh. We have got cops of 6.6 for heating and 4.0 dwh in Nov. That's a warm Nov in bristol and vaillant over estimate but my measurement suggest real numbers are still 5.8 and 3.9. So I suspect you can get more from yours. Try a lower weather comp curve. And try a Lower hot water temp. Until the unit struggles a bit to heat the house or your are short of hot water you probably have room to improve cop. Great series thanks.

[@TomBray-LowCarbonLifestyle]

Hi Joe Thanks for the message. 6.6 is amazing! How are you calculating that? I'd love to know all the details of your data etc.. what temperature are you heating to? Our system has been just over 3.8 in the last month. I have been tracking the same period over the last year and we have had a COP of 3.6 since end of June compared with 3.1 last year. I realise that we have had a milder autumn than last year but the changes we have made will have had some impact to. I've done exactly what you say, had the weather comp curve down at 0.3 for some of the last month. I think that is a bit extreme, but probably will settle on 0.6. This is compared with 1 last year. And yes, trying to keep hot water temp down. I was conscious we were a bit short when we had a friend living with us for a few weeks Sept-October, but down to 45 degrees now it is just me and my wife. What curve are you on? Great to hear of another real life experience!

[@TomBray-LowCarbonLifestyle]

Also - planning on doing a video soon on improving our efficiency including an update on the data!

[@joewentworth7856]

@@TomBray-LowCarbonLifestyle 6.6 is read directly from the vaillant appliance interface. referred to as 'working figure ' AKA COP. its a bit optimistic as i found it under measures elec usage by ~60w. and does not include the circulation pump usage ~ 30w . but it does provide a useful reference to see how changes have effected the cop even if its off a bit, its consistently off ! i have and elitech logger on the flow which gives me a indication of the flow temps. from November 7-14 flow for heating fluctuated between 26 and 30degrees and 14- 22 nov the temp was a bit higher 30-33 degrees. house is 20 degrees by day and 18 by night. we have only had a few days below an average of about 7 degrees. i have found curve 0.6 has been fine so far. we don't yet have a time of day tariff so i heat the DHW in the afternoon when the air is the warmest. something consider if you get PV. we live in a 1880s mid terrace town house tall and skinny. the basement has UFH so contributes significantly to the rest of the house by rising heat. (about 1/4 of total floor area) it has a loft and rear conversion so modern build / insulation standard. regular double glazing. Front and rear two stores of uninsulated 400mm solid stone / brick walls. (planning EWI at rear. $$$ ) basement is surprisingly efficient as most of it is never exposed to the outside temp, just the soil at consistent ~10degree so that helps the losses. for reference gas usage for march 21 to march 22 was 8900KWh with combi, so a fair bit bellow 'average' to start with . As a test to see how the UFH and rads would work with a heat pump i ran the combi at 40 flow the whole of that year as a test. I recommend to anyone to do the same test. you can always turn it up if your cold! great way to see if you will need significant changes to your emitters.

[@TomBray-LowCarbonLifestyle]

Thanks for the detail Joe! I hadn't realised I could get more data out of the Vaillant kit so today has been a learning day for me...! Absolutely amazed by your 6.6 COP, ours over the last month for heat has been 3.8. It sounds like your home is quite a bit more efficient that ours, we used just under 12,000 kWh of gas the year before moving to a heat pump. We set our temperature at 19 degrees with a set back of 17. We have a small area of UFH and then radiators through the rest of the house, that could be bigger if I am honest, the lack of surface area may be limiting our peak COP. We do live in a slightly cooler part of the country but I can't believe it makes that much difference. One question about your set up - what setting do you have the Room Temperature Modulation on - Expanded, Active or inactive? It would be interesting to compare all the controls to see what might help for efficiency. I like the 'heat pump ready' challenge, I think more homes would be ready than people think.

[@joewentworth7856]

@@TomBray-LowCarbonLifestyle the 6.6 i find hard to believe, beyond what I hear from almost everywhere and so i am still hunting for the error! . But Heat geek thinks it is plausible. I have played with the circulation pump to boost the flow in the ufh to 3.5l per min in each of the 2 circuits. The more flow the lower delta t ie higher the average water temp in the emitter and better output for a given flow temp. The additional pump energy is negligible.. We don't have the senso comfort so don't know what the room mod is. We have wiser drayton smart Tvrs and thermostats on 5 of 8 rads. That I think are fully open until they hit the desired temp then close. I have opened all other tvrs fully and as I have set weather comp pretty low the rooms don't over shoot 20 degrees. This I think keeps the max flow in the system keeping the radiators as warm as they can be for the low flow we are using. If you really want to get into the technical. I recommend heat pumps for the home by john cantor. We both work from home annul elec without hp is 3500kwh so that contributed to our heating and reduced the load on the hp a bit. And heat from 4 bodies and a cat add some thermal input too!

[@jamescollins3647]

Most important is not about your emissions but about your physical comfort, and how comfortable would a seventy year old feel. If you are lucky you might be 70 one day.

[@TomBray-LowCarbonLifestyle]

Hi James, we keep the house at about 19.5 degrees, that might not be high enough for someone in their 70s but we are comfortable. There is no reason why we couldn’t set the thermostat higher. The heat pump is able to heat the house to whatever we need. And, the whole reason of installing a heat pump is about emissions, it would be around 2/3rds lower emissions than a gas boiler for the same comfort.

[@jamescollins3647]

@@TomBray-LowCarbonLifestyle A lot of heat pumps are only giving warm radiators and you can not say what emissions your electricity is producing. Last autumn wind power failed and gas had to take up the shortfall, also all electricity flows through the national grid and cannot be distinguished. It all sound good but it's mostly wishful thinking.

[@TomBray-LowCarbonLifestyle]

Hi James, yes heat pumps (and gas boilers) work more efficiently at lower radiator temperatures, but the radiators are sized so that the space still has enough heat, not sure what you mean by 'only giving warm radiators', they are warm enough to keep the house at the temperature we want it..? You are right I haven't reported emissions second by second, but followed the national reporting methodology as any carbon reporting does. If I was being fair, I would report emissions from my region (North East England) that tend to be MUCH lower than the rest of the country, but I didn't... If I did, there are weeks at a time where my emissions for heat were 98% less than a gas boiler. Wind power didn't fail, that's an absurd thing to say, yes there may have been some still days but over the last 12 months wind power generated 19% of the UK's electricity. And yes, gas, coal, storage, nuclear power, solar power, and interconnectors to Europe provided power when the wind wasn't blowing, but that is how the system is designed to perform...?! We have a mix on the national grid, it changes every minute of every day, there are lots of websites that comment on this, I like www.mygridgb.co.uk/ because I have met the engineer behind it, and I like the national grid's www.carbonintensity.org.uk/. Does that explain any of your concerns?

[@robvossen8099]

Hi Tom, can you share the flow temperture you are running on for heating and hot water?

[@TomBray-LowCarbonLifestyle]

Hi Rob, hot water is set to 45. Heating is on weather compensation - last year, because I was playing with it a lot, it was probably a bit too high, hence we aren’t seeing efficiencies that some might quote. We’ve started this year on heat curve of 0.7, and today with outside temp of 12 degrees that means flow temp of 32. Which may now be too low…! But we’re comfortable today! At 0 flow temperature would be just over 40. Hope that helps.

[@robvossen8099]

@@TomBray-LowCarbonLifestyle do you know how often your back-up element is used for heating over 12months? In the netherlands we use a formula very often to determine the kw needs and based on this you would need 1100*8/1650=5,3 kw @-10 so if this formula is correct you should run at certain times on back-up heating element cop=1. Don’t want to be the smart quy just checking assumptions for my own house to determine what i need.

[@TomBray-LowCarbonLifestyle]

Hi Rob - I don’t think we use a back up heat element at all, just run the heat pump for heating when required. There is an immersion coil in the hot water tank but this is not used normally. Sorry if I misunderstood!

[@robvossen8099]

@@TomBray-LowCarbonLifestyle the coil for water is normal due to legionella desinfection. Do you have a split or a monobloc system? And are you able to check your cop at the coldest day over the last 12 m? If you are running at the limits i would expect a longer period @cop1. What is the rated scop @45degrees according to specs, do you have this data?

[@TomBray-LowCarbonLifestyle]

We have a monobloc system - Vaillant Arotherm plus. I don’t have data for the COP on the coldest day. The worst COP on a week timeframe was 2.3 (in the summer for mainly hot water), worst COP during the coldest week was 2.7. I doubt the heating part of the heat pump would ever have a COP near 1. At 45 degrees I understand the SCOP should be 3.77 (vaillant datasheet). Ultimately the average COP will be less because of hot water and legionella purge.

[@manfromdelmonty303]

Victorian terrace here. I’ve been told that if you can heat your home using a gas boiler with a flow temp of 50 degrees C, then your house is heat pump ready. Would you agree?

[@TomBray-LowCarbonLifestyle]

Hello! Yes that is a pretty good rule of thumb. A heat pump would be able to replicate those temperatures and keep you warm. If you were able to run at lower temperatures you would be likely to have a high efficiency system, if not, that’s fine, it should still be able to provide enough warmth! Tom

[@ivailostefanov23]

At what temperatures you run the heatpump on heating?

[@TomBray-LowCarbonLifestyle]

Hi Ivailo - we have it set up in a weather compensation curve that is about 32 degrees at 10 degrees outside and 45 at 0… so it varies as the weather gets colder outside. I might do a video on this!

[@ivailostefanov23]

@@TomBray-LowCarbonLifestyle And have you measured the standby consumption of the Arotherm? SCOP fo 2,96 for this climate is low compared to manufacturers data? The climate in GB is mild.... Currently I have installed Atlantic Alfea Extensa 10kW. it has standby consumption of 220 watts. This consumtion is not listed in the documentation. Listed standby is 43 watts. Circulation pump is around 40 watts at maximum. I use it for a month the maximum COP I have achieved is 2.3 because of the standby consumption. If I calculate COP without standby it goes around 3.85 with DHW and heating. My temperatures are 30 degrees at 12 outside and 45 at -10.

[@TomBray-LowCarbonLifestyle]

Hi Ivailo - fair point on the SCOP, I must admit that I think it is low because I spent a year playing with th/e controls and the heat curve because I was concerned it wasn't performing appropriately. I have learnt a lot! The heat curve last year was 0.5 points higher, I am seeing at least 15% higher efficiencies this year! Interesting about the standby power use, the meter I use to calculate COP is on the power supply to the whole system (including controller, pump etc), so that should pick up standby etc. I wonder if there is anything you can do to reduce standby consumption? Tom

[@ivailostefanov23]

@@TomBray-LowCarbonLifestyle Yes, you can. For my heatpump my guess is that it is refered to crankcase heating of the compressor. They use low amp power to compressor windings to heat the oil in the compressor. It works 24/7. But I`m curious is it tha same with other heat pump producers... For now can you meassure the standby consumption of your Vaillant?

[@justinholding02]

Do I understand that it is costing more to run than a conventional gas heating system? I haven't a wood stove and propane gas central heating. We have a lovely stone house that was built in 1897, would a heat pump really be worth it?

[@TomBray-LowCarbonLifestyle]

Hi Justin, yes I think our costs are a little higher to run a heat pump that our old boiler, there are a couple of things that could impact that 1) the way the energy market has changed with gas prices increasing more quickly that electricity, 2) if we were able to swap our gas hob for induction we could get rid of our gas standing charge, 3) if we were able to install solar PV or use a renewable energy supplier like rippleenergy.com?ogu=6499 then actually our costs could be very low as we would be generating much of what we use. A heat pump, sized and installed correctly, could heat any home, but old buildings that may be draughty and need to ‘breathe’ may need a very big system that uses a lot of energy. I can’t say either way without a detailed heat loss calculation and assessment of your current central heating. Something an MCS accredited installer should do It may not be perfect but with gas prices rising so much it could be a good long term solution.

[@justinholding02]

@@TomBray-LowCarbonLifestyle a got a quote for 18000€ for a heat pump, that's what I pay for about 15 years of gas and wood. So I think it's a no go for the moment..

[@TomBray-LowCarbonLifestyle]

@@justinholding02 That's fair enough, I don't think a heat pump is necessarily a cost saving intervention but has much wider benefits that we all need to consider. Hopefully, soon, costs will be more reasonable or government will help us all make the change.

[@justinholding02]

@@TomBray-LowCarbonLifestyle I live in France and they are really pushing the fact that they are cost saving. It might be the case on a large low temperature underfloor heating, but definitely not on conventional radiators at 60-70 degrees Celsius

[@TomBray-LowCarbonLifestyle]

@@justinholding02 Ahhh interesting, I can't really comment on french energy prices, electricity may well be much cheaper as much of UK prices are policy costs / tax. What kind of cost do you pay for electricity per kWh? And for propane per litre? Our heat pump runs with conventional radiators but with lower flow temps than 60-70 degrees, I think on the worst day flow temps will be up at 50. I suspect you live in a slightly warmer climate than North East England, and if so, the efficiency of a heat pump would be much higher. A lot of my stats won't be relevant to your situation

[@timbartlett712]

Hi Tom I am about to install an aroTHERM plus 7 kw ASHP and am keen to measure the electric input and heat output. Can you let me know what you have used to achieve this please? There is a feature in the controls extract copied from data sheet "Energy yield The Vaillant heat pump interface will display something called energy yield. This is a calculation of the amount of heat energy that has been absorbed from the air by the heat pump. This is not the heating performance of the heat pump. This figure is used as part of the calculation to give the heating power and the efficiency of the heat pump. You can view this if you are using the Vaillant app" Have you any experience of this feature and it's accuracy?

[@TomBray-LowCarbonLifestyle]

Hi Tim - we actually have a heat meter and electricity meter built in dedicated to the heat pump system. So the figures I use are taken from them that measure all the heat generated and all the electricity used by the heat pump and the circulating pump. I have not been able to correlate the data on the vaillant controller with what I read on the dedicated meters. Although the energy yield figure could be the ‘free energy’ taken from the ambient air. So added to the electrical demand, should give the total heat generated by the unit. But when I do this I don’t get the same figure (it’s close but different!) Probably some value in the vaillant figures but not perfect for energy analysis

[@timbartlett712]

@@TomBray-LowCarbonLifestyle Hi Tom thanks for quick reply. Can you let me know which heat meter and electricity meter you have installed and where did you get them from please. I will fit the same and the can see what SCOP's we can achieve.

[@TomBray-LowCarbonLifestyle]

Hi Tim, sorry it has taken me a while to get back to you! I was on a charity bike ride last weekend so away from home to get meter info... our heat meter is the sontex superstatic 449 - www.metersuppliers.co.uk/sontex-superstatic-449 which I think was the fairly standard heat meter for RHI installations. Electricity meter on the heat pump system is an Eastron SDM630 Hope that's helpful!

[@joewentworth7856]

I wish I had Metering.. but you can get good amount of info from the vaillant wiring centers. It has environmental yeild from the weather comp unit but energy yeild is available on the wiring center essentially the total energy output. The cop is oddly referred to as working figure. Its a bit of an over estimate as it does not include the consumption of the electronics or your circulation pumps but is a useful refference .

[@TomBray-LowCarbonLifestyle]

@@joewentworth7856 Hi Joe - interesting! I didn't know you could get data from the wiring centre? Could you talk me through that? It looks like I am only able to see data from the previous day. I think the environmental yield and power consumption figures in the sensocomfort are fairly close to what our heat meter and electricity meter read. COP for the last month of about 3.8, over the last 17 months, just over 3.

[@Liquid_Badger]

I seeing how you have had heat & electric meters fitted, how do they compare to the on board metering on the control? Thanks

[@TomBray-LowCarbonLifestyle]

Good question, if I am honest, I have ignored the Vaillant controls energy data as I am not sure what it is telling me, I know what the meters are reading so focussing on that. Have you used the Vaillant controls and the energy data information menu? I thought environmental yield is equivalent of heat generated and power consumption is electricity used... but the readings are miles away from the heat and electricity meters.....

[@Liquid_Badger]

@@TomBray-LowCarbonLifestyle the environmental yield is the total heat produced and you divide that by the power consumption of the installation for the COP. Really curious to see if the external metering is different to the on board. I’m not convinced that the on board is 100% accurate. I also have a vaillant 5kw ASHP fitted, super happy with the performance. Thanks for your reply

[@TomBray-LowCarbonLifestyle]

It is very different. I’ll check later how different and comment!

[@Liquid_Badger]

@@TomBray-LowCarbonLifestyle thank you 🙏

[@TomBray-LowCarbonLifestyle]

Just looked at the controller details vs the heat meter / elec meter, since installation the controller suggests it has produced a total of 6597 kWh of heat and used 3194 kWh electricity, or a COP of just over 2. The heat meter and elec meter on the systems says we have produced 10544 kWh of heat and used 3608 kWh electricity, at a COP of 2.92, unsure what the controller is measuring but quite different!

[@RodneyABC1]

Do you run your heating 24/7 or just during select hours?

[@TomBray-LowCarbonLifestyle]

Hi Chris, we have it at different set points during day and night and the heat pump runs to meet those set points. Tends to be 19 degrees C during the day and 17 overnight… So, could be 24-7 but probably not.

[@manfromdelmonty303]

Lovey house - looks Edwardian though :)

[@TomBray-LowCarbonLifestyle]

Thanks manfromdelmonty! We found our recently that the street was built in the 1870s. I suspect the bay windows were added later. No other homes on the street have them. Thanks Tom

[@neilashdown6854]

Did you increase your radiator sizes ?

[@TomBray-LowCarbonLifestyle]

Hi Neil, two went from single panel to double but mainly stayed same size. One way to check whether you need to would be to set boiler temperature to 45degs and see if all rooms are comfortable with heating on We have been happy all winter with ours

[@neilashdown6854]

@@TomBray-LowCarbonLifestyle Hi Tom thanks for getting back to me much appreciated. I am just about to replace my bio mass boiler with a RED heat pump. We have part underfloor and radiators. As we are refurbishing the complete house we are adding additional insulation to all external walls and have just installed triple glazing our house was built in 1884. I have based my design on a 35 C flow which works for the underfloor and have increased all the radiator sizes to deliver room losses at this flow temperature. Great video mate keep up the regular updates.

[@TomBray-LowCarbonLifestyle]

@@neilashdown6854 that sounds like a great project and will have a big impact. Would love to hear about how the house performs when you’re finished. Particularly the comfort of triple glazing. 35 degs will give you a really efficient system Ours is running with a COP over the winter of just under 3, I suspect yours will be much higher!

[@ajh8558]

Good channel mate. Have you thought of using a time of day electricity meter? Could allow for low carbon heating of hot water specifically?

[@TomBray-LowCarbonLifestyle]

Thanks mate! We use a time of use tariff with our smart meter that means we can charge a hot water tank overnight at a cheaper rate (5p per kWh rather than 15p on our current tariff). Most of our hot water is heated between 1230 and 430am with the heat pump like this. But majority of heat pump output is during the day (when we need the heat).

[@jayyelland8289]

So what are the trees & Flowers going to absorb when the co2 has been reduced?

[@edc1569]

You know carbon goes round in a cycle like water, you exhale some, plants absorb it, animals eat the plants, you eat the animals, and so the cycle goes on. The problem is digging up billions year old carbon and adding more and more of that to the system.

[@TomBray-LowCarbonLifestyle]

Hi Jay - exactly what Ed says, we currently have 50% more CO2 in the atmosphere than in the last million years, and it is getting worse, because of the oil, gas and coal we have burnt over the last 170ish years. 2022 sees the highest concentration of CO2 in human history. We need to stop emitting CO2 as soon as possible, urgently.

[@jayyelland8289]

This clim,ate crisis is all a hoax, even the head of WEF, K'laus Schw.ab says it , least in your head you are doing the right thing

[@ChrisLee-yr7tz]

@@TomBray-LowCarbonLifestyle I'm with you that it's a huge problem but the elephant in the room that nobody ever wants to discuss is global population. I don't even know why it's a taboo subject. Conspicuous by its absence at every level of international discussion, do you really think switching to ASHP is going to make a blind bit of difference at a global level given the population increases? I really wrestle with this problem. By 2050 we'll have another 30% of people in the world meaning we have reduce output in every single source by like 25% just to stand still. I understand it's another topic from heating your house, it's just when I see this as presented as part of a solution to these global issues I think it's a bit delusional to think it'll really make any difference.

[@TomBray-LowCarbonLifestyle]

Hi Chris, I think population is discussed, but often in fairly unsavoury ways. Which groups of people might we say should reduce their population? Should we in the west tell people of colour in other countries they can't have children? Who has the right to ask that of anyone else? What are you proposing? The reality is that an individual in the west (North America, Europe, Australia etc) has emissions multiple times higher than someone in a developing country, our economies have been built on over-consumption and pillaging of the natural world, and our standards of living are built on high emissions, we need to deal with that 1st and foremost, and build a global economy that can support 8 / 9 / 10 billion people sustainably, equitably, fairly. We have the means to do that. And it starts with governments in countries like the UK funding rapid decarbonisation of society, including heating systems in homes, so heat pumps have a really important role to play. If we had 25million heat pumps rather than gas boilers then society would be very different and I think in a positive way!

[@ascelot]

Dont think my house is insulated enough to get heatpump and cant install better insulated windows and front door due to conservation restrictions.

[@TomBray-LowCarbonLifestyle]

Hi Ascelot, Thanks for the comment, i'll come back briefly... a heat pump can heat any building, if sized and installed correctly. It doesn't necessarily need the highest levels of insulation. A gas boiler is expensive to run in a poorly insulated building, a heat pump would be similar cost to run. It is frustrating when conservation restrictions prevent energy efficiency, and I wonder whether there is a challenge or campaign you can start with the local authority? We definitely want to conserve heritage, but if this means buildings are expensive to live in and therefore impossible to maintain, are we conserving them? I wonder what the local authority's plan is for reducing emissions if they won't facilitate energy efficiency... Our home is a victorian terrace, we have upgraded to double glazing (there are some conservation sensitive double glazing products out there) and have loft insulation and a modern extension at the back, but we aren't the best insulated building, and a heat pump performs pretty well. It would definitely be a challenge, and I wonder whether your efforts would be better targeting energy efficiency or emissions elsewhere in your life, but at some point, I suspect a heat pump will be needed to replace your boiler with. Thanks for commenting Tom

[@ascelot]

@@TomBray-LowCarbonLifestyle Thanks for reply, currently have standard combi boiler, I am looking at 2 things, applying for planning permision to change windows/doors as well as looking into thermal imaging for heat loss on house.

[@bibihunden]

Low Carbon emission figures with your heat pump??? Does all your electricity comes from windfarms, or maybe solar cells at night? How about your EV?

[@TomBray-LowCarbonLifestyle]

Hi Ole, thanks for commenting, to answer your question… I definitely don’t claim that our heat pump is zero emissions but a few points to make in reply. We don’t burn anything locally but use power from our electricity supply that comes from a number of sources. If we assume average emissions for 21/22 as reported by our government department BEIS then our emissions were about 65% lower than our old gas boiler. But, we could assume our electricity supply was zero emissions as comes from a company that sells 100% renewable electricity. I don’t assume that as I know our grid in the UK is a mix. I could assume that our electricity comes directly from the generators around where I live (this would be the reality of the physics of electricity system). Locally, our electricity grid is mainly powered from the Hartlepool nuclear power station, offshore wind and solar generators. The emissions of electricity in the north east tends to be very low. Finally we could assume that adding a demand to the electricity grid which increases the marginal generator demand, which tends to be coal or gas, so emissions could be based on power from gas power stations. As long as the emissions from the marginal generator are less than 600g CO2 per kWh (which is likely for gas power stations) then our heat pump will be lower emissions than our old gas boiler. The more low carbon generators on the grid and eventually when we get solar PV, the heat pump would be even lower emissions I don’t have an EV, I ride a bike, but if I did have an EV, the story is similar and using emissions reporting conventions similar to what I mention above, the emissions for an EV in the UK tend to be about 65-70% lower than any equivalent fossil vehicle Thanks for commenting.

[@Allegedly2right]

Haha the good old days why is no one asking about the price in ££ to heat 1 room fan heater,on thermostat nice warm room heat pump nice warm house guess what’s the cheapest way to keep yourself warm.Heat Pump not possible to warm just one room must heat whole house completely wasted energy.had my heat pump 2 years switched it off and bought a fan heater Heat Pump 40kWh fan 2.5 room is warm in 10 minutes turn it of and on Money in the bank.

[@TomBray-LowCarbonLifestyle]

Hi O Know - it’s a good point, we should only heat the spaces we need to heat Tom

[@Allegedly2right]

@@TomBray-LowCarbonLifestyle We all know that Tom this is every Heat Pump COP 3 for 1 but that is divided into 4bedrooms 1 kitchen 2 living rooms and a hall that’s a lot of heat.Heating empty rooms £££ fan 2.5kW room is habitual within 10 minutes thermostat controlled Happy Days,I like your videos honest reviews but I can’t afford to save the planet and stay warm.

[@TomBray-LowCarbonLifestyle]

@@Allegedly2right I’d actually argue that if you are using an electric heater to heat one room and that is all you need then you are saving the planet and staying warm… I want people to replace gas boilers with heat pumps, but heating more efficiently by heating less is a good step too. A 4 bedroom house is a big house, so would be expensive to heat all of it using any technology. But moving away from fossil fuels, and to electric based heating, will give us a path to low carbon homes. Top man!

[@Allegedly2right]

@@TomBray-LowCarbonLifestyle Tom the point I was making is a Heat Pump will not do it,not possible for most of the U.K. when you switch it on it pulls 5 to 7 kWh and takes 45 minutes for heat to arrive 15c up to 18c that will take 2hours,it switch’s off and has to start up again.How do I get round that no thermostat on the market it is on or off won’t perform the same as gas boiler it won’t simmer on or off.Tom I am thick haha cheers.I have them coming out for the service and to reset the settings but there are none Grant Aerona3 not user friendly Space Age Technology but no one knows how to use it I kid you not.Cheers Tom

[@BenIsInSweden]

@@Allegedly2right You are misunderstanding Heat pumps in general. 5kW and 7kW heat pumps are on a 16A fuse, meaning the maximum they can ever draw from the wall is around 3.7kW, but their Rated max current is smaller. The badge rating (5kW/7kW) is their heat output rather than the electrical usage. And most of the time they will never use their max current. As for heating empty rooms, you are invariably heating those rooms regardless, maybe not to the same temperature, but unless your inner walls have as good (or poor) insulation as your exterior walls then you're always losing heat into them regardless, the other exception to this is if you're only using a small percentage of the rooms all the time. It is often with a heat pump system (and to some extent a boiler) better to still heat those rooms to a slightly lower temperature - e.g. 18C instead of 21C, so the radiators in the occupied rooms aren't needing to work at a higher temperature to keep them at 21C. Lastly, heat pumps excel at maintaining a set temperature for little energy - you could compare this to a petrol car, of driving 100 miles, does it use less fuel driving at 30mph constantly, or accelerating to 100mph as quick as possible, and stopping every 10 miles for a break? Same for heat pumps, trickling in heat into the property at the same rate it's lost at. Duty Cycling is an efficiency killer, and it is to some extent the same for a gas boiler, just not so pronounced.

[@lukelisley1638]

This guy is clearly being paid to promote these pumps. He doesn't mention any of the insulation improvements he made to his house.

[@TomBray-LowCarbonLifestyle]

Hi Luke - I’m not being paid by anyone to promote heat pumps. I’ve talked numerous times on the work we did on this house. Extension at the back, double glazing, 300mm of loft insulation. Are you being paid by the fossil fuel industry to keep burning stuff? You must be if you think we can afford to not move away from fossil fuels!

[@waynekerrr9027]

Who cares about emissions...,..just give me cheap heating ...simples

[@TomBray-LowCarbonLifestyle]

I care. A lot. Without rapidly reducing emissions we will see the world damaged permanently, food insecurity, extreme weather, drought, rising sea levels, mass movement of people, destruction of habitat and loss of species. Reducing our emissions does our bit, even if in a small way. And moving away from fossil fuels, like gas, supplied by thugs like Putin, means in the long term we can reduce costs. Whether that is through energy efficiency like insulation or through replacing a boiler with a heat pump.

[@waynekerrr9027]

@@TomBray-LowCarbonLifestyle That's all very well for wealthy people who can afford these silly extortionately priced heat pumps that cost more to buy, and more to run, and don't heat as efficiently as a boiler..so I stick with my original comments ..I prefer the earth to get warmer actually, fed up of living in the cold.. simples

[@TomBray-LowCarbonLifestyle]

@@waynekerrr9027 thanks Wayne Kerr, that’s why we need government support to help make the change, and stop subsidising fossil fuels over clean energy. At the moment gas is subsidised over electricity, even though it’s worse for the environment and just supporting Putin We’re much more comfortable in our house now as we don’t have the peaks and troughs of a boiler ramping up and down and we don’t have a noising combi switching on and off whenever we turn a tap on If the world getting warmer means there are food shortages, extreme wind, flooding etc, would you still prefer it? You’ll barely notice 2 degrees higher average temperatures but crops will, water will, wildlife will, the poles will.

[@waynekerrr9027]

@@TomBray-LowCarbonLifestyle Don't get caught up in all the hype, of we're all going to die because of climate change BS..Everybody just wants cheap price energy, and now..and they not going to find it in these stupid overpriced heat pumps.. You'll be saying go and buy a cheap electric car for £50k next, to go with my nice £15k heat pump...not sure which planet you living on...probably planet Rischi Sunak

[@TomBray-LowCarbonLifestyle]

@@waynekerrr9027 I’m definitely not on Rishi Sunak’s planet! And I’m afraid I’m signed up to the hype, I’m an engineer who’s look at the science and working to make a change as soon as possible. I completely agree that costs to but an EV and install a heat pump are completely unreasonable for most, but the richest tend to emit the most so they should pay what they can afford, and the government should help the rest. Although I would say, a bike is much cheaper than an electric or a fossil car, and much lower emissions than both… I’ve done a few videos about EVs, the positives and the limitations. My conclusion is we need to drive less!