Great video. Thank you. I've had a heat pump for 4 years. This is what I've learnt in order of importance for cost savings: 1) Reduce flow temperature as low as possible that still allows the house to heat up from offset temperature (say 17 degrees in my case) to comfortable living temperature (say 19-20 in my case) in a time reasonable for you. There's little point in setting it so low that it takes 6 hours to raise temperature 2 degrees. 2) Lower hot water temperature as far as you can and don't have the heat pump heating water all day. Use the timer to heat the tank for a given 'bath/shower' period only: it's far cheaper if you can agree to shower/bath just in the evening or just in the morning. I have a family of 5 which makes this difficult to say the least.
@@A.P.Garland Sure, but it would be helpful to have cop data for the winter months alone. Most of us don't run - and can't afford to run - central heating boilers throughout the year.
@anonanon289 I've never been able to gather and plot accurate COP data for my ASHP. Needless to say, when it's -5C outside for days on end and I have weather compensation on (flow temperature increases as outside temperature decreases) COP is horrendous. When it's warm enough outside not to even need the heating on, COP is brilliant, but never leveraged because the unit is off.
It depends on what metric you use I guess. If we look at www.degreedays.net/# at my local weather station, in winter 21/22 (Nov-March) there were 1434 degree days, 22/23 = 1489, 23/24 =1471. Degree days give a metric of how long and how far below a certain point the temperature was, so therefore how much heat was needed. This year, slightly less heat needed than the year before, which was quite a bit more than the year before that. It may be that the last three winters have been warm, although the met office said this January was 0.1°C lower than the long term average. Anyway... yes weather impacts on performance of a heat pump, I have done some videos specifically about heat pump performance over winter here for January - ua-cam.com/video/GmsMV6ApwO4/v-deo.html and here for the whole of winter - ua-cam.com/video/FnVsfbL4owQ/v-deo.html If we have a particularly cold winter, heat pump performance will drop, maybe by 10% (my estimate) but all dependent on temperature Tom
We got 5kW aeroTHERM plus installed in August and have been tweaking various elements to see we can optimize efficiency and comfort. Still too early for any proper conclusions. The weather compensation curve was set to 0.7 when it was installed, but I've dialed this down to 0.5. First full month was September and we achieved a COP 4.0, with more heating in the mix this month we're seeing an average of 4.4. House is noticeably more comfortable with a consistent temperature than our old gas combi-boiler where the rooms were either too warm or too cold, and rarely just right. This combi-boiler was 24 years old so would have been lucky to be 75% efficient, so I expect we're now using less than a 1/5th the energy we used to for heating. We have requested Octopus to come and remove the Gas meter, once that is gone we'll save a roughly £100/year on standing charge. Often folks talk about gas vs heat-pump costs per kWh of heat but don't factor in the standing charge, with this saving you don't actually need to achieve the as high COP to break even. At the same time as installing the heat-pump we got 2.8kW solar and 15kWh of battery installed, in September in generated a 207kWh which was more comfortably more than the 134kWh consumed by the heat-pump for hot water and space heating. We still needed to pull an average 4kWh/day from the grid, but this is way down from 25kWh we would have consumed of Gas and Electricity in a typical September. I'd expect in the June and July we should be mostly off grid.
Hi Tom, thank you for the great video. I would like to know what your temperature settings are and also how do you change them in relation to Octopus Agile tarrifs? For example, what time and what temperature is your setback, or what time do you heat your water? How does your daily schedule look like? We had our heat pump installed in June, and this is our first week using the heating. I am looking for some ideas on how people are using the settings to increase efficiency. Many thanks! 😊
I'm still in the initial testing stage, but am trying 20 degrees until 9am, then 21 degrees all day, with slight increase in temp to 21.5 degrees between 3 and 4pm, before the 4 to 7pm to reduce use during that period. Setback is currently 18, but likely to increase. Two periods of hot water heating- 03:00 'til 04:00 and 13:30 until 15:00.
Hello - thanks for the comment - temperature settings keep the house at a constant temperature so 20°C 24-7. We don't change them related to the agile tariffs. Although I should note, the thermostat is in a room and external sensors for the weather compensation control are both south west facing, so our heat pump tends to run less hard during the 4-7pm peak because of our specific set up. We don't have a set back overnight. Heating water - we have the system to run outside of the 4-7pm peak, if the temperature in the tank drops by 5°C it comes on to heat the hot water. Which can happen in any of the 21 hours outside the peak. My conclusion, particularly for heating settings, is to try to push the weather compensation curve as low as possible and leave the heating to run as long as possible. This has led me to ignore any time settings, even with octopus agile. I am happy with this and means the house is always comfortable. I started with a set back of 17°C overnight, but this also tends to be when electricity is cheapest, so it didn't really make sense not to use the heating system with cheap electricity. Slowly and surely I reduced set back, until simplifying the system to run constantly. Others may come to different conclusions! Hope that is helpful?! Tom
@@TomBray-LowCarbonLifestyle Surely it would be a lot more efficient to heat the hot water once a day while the air is warmest and electric cheapest - at 13:00-16:00? I do the same thing with my gas boiler for DHW only. Once we've had a shower in the morning I don't care if the temp drops a bit throughout the day and it's got to be more efficient to heat up once from 40°C than constantly trying to get it from 55° to 60° ...or whatever.
@@johnhunter4181 That is a fair point John, and something I will have a think about! First thought is on cost of electricity during the day and whether it tends to be cheaper overnight....
This is my 2nd winter with a heat pump. No solar, no battery. I have my setback temp at 18°c and target of 20°c to 21°c. I pay £130 a month and currently on a fixed tariff from eon next which is cheaper per unit than the price cap. I have my heat pump on schedules, 7:30am to 11am and then 17:30 to 11pm. Not sure if this is the right thing to be doing, but there's no big fluctuations in the temperature. And if I do feel it when it's out of schedule running then I click up the thermostat a degree or 2. Then it just runs when it needs to.
That sounds good if it works for you! My only thought would be to increase the set back temperature slightly, and push the flow temperature / weather compensation curve down slightly, might get a little more efficiency out of the system and cut costs slightly But, if you’re happy, maybe not worth tinkering!
@TomBray-LowCarbonLifestyle I've had a look at the weather comp curve and it shows at -3°c the flow would be 45°c so what you're suggesting is to increase the set back temp to say 20°c and my target temp to say 22°c but lower the curve flow slightly to say 40°c ? If I am understanding you correctly Tom?
I've got solar, heat pump and a battery in a 1970s house. It's a big outlay and this will be our first full winter, but the Cop is hovering around 4.7 with weather compensation on 24/7 and we've turned off the gas, so no gas standing charge. Octoplus tariff gives us 3 hours of cheap electricity at night, so that tops up the battery. So far so good.
@@manoo422 What makes you think he doesn't? Vaillant ones give the COP figure in the app, which some have confirmed to being close to accurate with external measurements (open energy monitor). A COP of 4.7 for this time of year isn't exactly a stretch. Check heatpumpmonitor with limiting to the past 7 days, about half of the 185 listed have achieved a COP of over 5.
Do you still use gas i.e. for cooking. If not and you only use electricity, do you only have one standing charge to pay, i.e. you don't pay the gas standing charge?
Good question - average cost is about £13k, so yours may be a bit smaller / cheaper than average. So £10-12k? And then after the grant, between £2.5-4.5k…? Although someone like Octopus may be cheaper, and some installers may be much more expensive!! Tom
Thanks for the honest comparison. I'm on octopus agile. The prices shoot up between say 4 and 7 pm (as you would expect). How do you get around this with your heat pump? Does it just switch off between 4 and 7? And if so, doesn't the house get cold during those times?
Hi Philip, good question, I actually tend to just leave the heat pump running during the peak time, in an attempt to keep the weather compensation curve as low as possible. But program hot water and anything else that can be delayed (washing, washing machine etc) to outside the peak times. As the peak is only 3 hours, the average is brought down by the lower cost 21 hours, so for most of the year (except 1/2 days) my average rate has been much lower than a price cap rate, without really changing behaviour significantly. You could program the heat pump with a set back rate for 4-7 but I have not done that. Hope that is helpful! Tom
How do you decide the size for the heat-pump.? I’ve been looking at the aerotherm + for a 3 bed terrace of which we have added 50mm cello Tex to all external walls , with rear having 100mm cavity on lower ground.
Hello - that would tend to be a calculation done by your installer based on heat loss of your home. I have done a video about the steps to getting a heat pump here ua-cam.com/video/nbaAibu0EgM/v-deo.htmlsi=GSq6_moiS6zDU2w_ This includes some thoughts on heat pump sizing Thanks Tom
Hello! I did a video about noise here - How loud are heat pumps? - Low Carbon Lifestyle Episode 38 ua-cam.com/video/ksrAZM-ldI8/v-deo.html We don’t really notice it in summer, partly because it is rarely running and when it is running, it’s fairly subtle. We set our most occupied space to about 21°C but other rooms in the house are a bit lower. Thanks for engaging with the video! Tom
Is this MCS certified? Just looking at the thumb nail seems it seems to exceed the reflective surface limit (max allowed is 3) anything within 1m on the unit. Floor always counts as one, back wall would be 2 that leaves left or right of the unit only, both left and right seem to have a wall within 1M so wouldn’t that count as 4 reflective surfaces? Not to mention clearances for servicing/maintenance and door within the protective zone. However may just be the camera angle
Hello - yes it is MCS certified, so I am interested to read your comment, although the wall on the left is more than 1m away from the heat pump. The clearances are ok on each side except the right hand side, which is too close when considering the manufacturers guidance. However we just had a vaillant service and the engineer said it was not a problem. Although you are right to point out these things, I guess having a bit of flexibility to install in tight spaces will mean installations can go in more homes. I wonder whether MCS needs to have more flexibility in the future...?
Hi Mustang - good questions - reliability, nothing gone wrong in 3 years with the heat pump, I’ll let you know when something does. Lifespan, Google suggests 15-25 years, similar to a gas boiler if not better. Replacement cost, not sure, the heat pump itself is not particularly expensive. Thanks Tom
Hi tom just wanted if I can to get your view. We had a heat pump fitted by global energy in sept 2024. It has a weather compensation system that varys according to the outdoor temp. This system can be navigated and adjusted by the company at their end. I recently rang them to ask could they check over the settings. They did and assured me its set at the most efficient. Its set at Upper AT heat 15 degrees. Lower AT heat 5 degrees. Upper WT heat 55 degrees Lower WT heat 34 degrees. Water temp 48 degrees. We run the heat pump 24/7 set room temp at 20 degrees. 21 degrees from 5.30 pm to 10pm. We are using on average 20 kw per day we are all electric with no solar panels. My question is with the experience you have obtained. Do you think that amount of usage is right. Which will only increase now as the weather gets colder. Thanks peter
Hi Peter, it is difficult to estimate how much a system should be using because I am not sure of the size of your home, age, insulation or location etc.... But I think the settings may seem a bit high...? For my system, the highest water temperature when -5 outside will be around 45°C, at 15°C outside the water temperature will be at about 25°C. So I suggest the weather compensation curve could be lowered slightly. We have used about 13 kWh per day so far in October / November this year for the heat pump + 3-5 kWh for other electrical loads. Hope that is helpful Tom
Thanks tom. We live in a 3 bed detached stone built property which has had all external walls insulated . We are in northwest NR. Southport. To give you an idea. Yesterday Sunday 17th Nov we used 39 KWH.. Which to me seems excessive. But I'm not sure
Your flow temps are way too high for efficient operation. You need to be running at a max of around 40c and a min less than 30c to get good efficiency, but I don't know if that would keep your house warm enough. Ours is on weather compensation at a max of 38c and a min of 26c, so our max flow temp is almost as low as your minimum
Thanks for your reply David. I've checked back with my installers and they assure me my settings are set at the most efficient it can run. So don't know. It's not as if I can argue with them as I'm only learning myself about how the system runs
Great video. Out of interest, how do you carry out the electric and heat metering on your system? We're shortly installing a Kensa ground source heat pump and I would like to keep logs of the data to calculate COP. Do you monitor the temperature in your hot water tank and if so how?
The vaillant App gives the data in Tom's case I believe. There are also 3rd party monitoring tools from open energy monitor that your installer can fit for you. The kit is pretty expensive ~£600-£800 if I recall, but generally worth it as it logs the data in real time, so can help spot issues etc.
I understand it can, but we do not have it set up in that manner. Cold water in radiators leads to condensation and pools of water under radiators. So not ideal…!
Just a had a 6kw aira heat pump installed yesterday with all radiators replaced with bigger ones. DNO request now pending for a 6kw solar system. Also have an ev so will be looking to investigate best tarrif options
@TomBray-LowCarbonLifestyle hoping so with the aira system they claim to monitor everything remotely and make adjustments. I have already turned to water temp down to 50c as the hot water is extremely hot when set at 55c. Also an option to program heating the water tank during off peak hours with octopus go but says this will swith off the intelligent monitoring. Will need to investigate further 👍
We've had our heatpump for three month now and also my wife praised the heat to be 'more comfortable' now. Also from what I can tell already we'll not be reaching the amount of costs we had with our oil boiler. Also very interesting to hear the installation costs in England. Here in Germany, I paid double the price you paid for yours (26000€), I wonder why that is. I got back 9000€ from the government though.
Thanks Tom for another great video. My 7kW Vaillant Arotherm+ has been in about 3 months, and is working well. It'll be even better when the ground floor is insulated, hopefully before too long. Otherwise a mish-mash of IWI, 30yo cavity wall insulation, extensions with 2000s insulation and an uninsulated hard-to-fill cavity wall. Mainly double glazed but with two triple glazed bay windows. Curve currently set to 0.5, lower than design flow temp of 45 degrees at -3, but expect to increase to 0.6 at least when weather gets colder, and while ground floor is still draughty. Unlike you Tom, my journey started with making my gas boiler behave as much llike a heat pump as possible with flow temp reduced to 50 degrees, running 24/7 with overnight setback of a couple of degrees. I learnt as much as I could before taking the plunge with a Heat Geek install. Chose design target temp of 18, and planning on upgrading more windows and insulating/improving insulation of roof spaces over the next few years to improve comfort and get temps to 19 at no extra cost. Roof not really suitable for solar PV, and no battery, but Octopus Agile tariff is saving me around 10% compared to the Flexible tariff. The gas meter was removed a month ago, so also saving on standing charges. I didn't really think much about the hot water side of things until well into the design when Heat Geek swapped in the Newark at a much higher cost. I haven't been too concerned with payback times but with my low hot water use it would have taken decades to recoup additional cost of the Newark cylinder so I asked for the Vaillant hot water tank to be reinstated. It might be less efficient, but energy used to heat water to 50 degrees over last 3 months has averaged about 0.7kWh/day. Will be another 9 months before I have electricity costs for a whole year, so far too early to say whether I'm saving any money.
Thanks for taking the time to comment, I am pleased that you have had a good experience so far, and hope it continues when the weather gets colder. You may find that the 0.5 curve is sufficient, but little harm in changing it if needed! Look forward to hearing how you get on this winter Tom
Live in a village so 100% electric, no gas line. Our heat source pump is over 7 years old as that’s how long we have lived in this house. I think it is too small and our electric bill is over £400 a month in winter and will probably be a lot more this year. I find it takes a long time to heat a house, so heating on about 19 C when out and turn it up when home. Since living with this system I have never felt warm in winter.
Hello m0ther0ne - thanks for sharing your story, there may be some settings you can change to improve comfort and reduce costs. A 7+ year old system should still be working ok, but may benefit from some maintenance. My home would be about £250-£300 in December and January. You say it takes too long to heat a house, that may be an issue with your heating approach, mine also takes a long time to heat up, but can easily maintain comfortable temperatures. What temperature are you hoping to achieve? Do you spend long periods away from home? It could be worth leaving the system at a higher temperature when you go out so that it can maintain that temperature when you want it...? Sorry that you haven't felt warm in winter but hope things can be better!
If your heat pump uses air on the outside unit, I would clean the air part of it. If the unit's air part is dirty, it can extract less heat compared to when it's clean.
Like the comments below, it may well be more about how you use it than anything else. Heat pumps work nothing like gas or oil systems, with much lower water temps in the rads. This needs larger rads, and the whole system needs setting up well. Never turn the pump off, use all the rads (the heat pump should be sized to the volume of water in the whole rad loop), and modulate temperatures with weather compensation. If your system has this it may be turned off, or the sensor may never have been fitted, or linked if one has been. Some installers don't understand much about many aspects of heat pump installation and use. If you want 21 C for general living, don't drop the night temp to less than 18 C. It uses more energy to regain temps than maintaining them. This is true even if you have terrible insulation values. If insulation values are poor, there isn't much more you can do to make a heat pump perform well. Using the fabric of the building as a heat sink is also important. My modest 1980 house, with equally modest insulation values, cost just over £200 a month to be properly cosy during the coldest months last winter. It looks a little shocking, £200 a month, with only a state pension. But during temps of 10-15 C it costs nearer £100, and almost nothing in summer. I don't turn my system off even then, as summers where I live are cooler and for longer than in the south, and a little top-up warmth, at negligible cost in the cool evenings is most welcome. A neighbour who still has night storage rads pays nearly the same every month to have a much cooler house, something they are beginning to appreciate more as they get older... So, sometimes more is less, if you see what I mean.
So how's such a system really going to work successfully in a 3 story, 6 bedroom solid stone victorian house with large single glazed sash windows in each room and x26 double radiators, currently powered by a 85kw oil fired boiler? Would have to be a pretty big heat pump to cope with the required heat output and therefore I suspect m unbelieveably expensive to have installed and then run.
Thank you Tom , very informative video. I got my heat pump in July this year and just use it for hot water currently as my house is a new build (B EPC). Your tips will be handy as I keep it going through winter now .. 😊
Hi Alan, we have thermostat set to heat our home to 20°C. We store water at 48°C. One of the key points is the flow temperature from the heat pump and having that set up with weather compensation controls to vary with the external temperature, i.e. radiators warmer when the weather is cooler and vice versa. Depending on your system this could be done in a variety of ways but I hope was set up like that when it was installed. Hope that make sense? Tom
@@TomBray-LowCarbonLifestyle great. We already have the water at 48 (50 was a bit hot frankly) and are experimenting with the thermostat otherwise. I need to check the curve setting but we certainly have the weather compensation running from early experiences
We are about 110m2, and a 5 kW heat pump. An installer should do a detailed heat loss assessment on your behalf rather than using comparison or rule of thumb (but for to have an idea!) Tom
Just had mine installed. Its an Arotherm 5kw which looks to be the same as yours. Currently curve set to 0.4. System is designed to 45c flow at -2. and got a new Heat Geek cylinder. Interesting to see what my annual figures are. Its on OpenEnergy Monitor heatpump list.
Interesting stuff! What model is your Vaillant? I note the aroTHERM Plus use R290 for the refrigerant, and as such seem to have stricter requirements for installation, notably with regards clearances to establish a protected zone. Further - I note building regulations state an ASHP must not to be installed within 1 metre of any property boundary. Is the wall to the right of the pump not a boundary wall, and what about the wall to the rear of the unit, is that a boundary wall with a neighbouring property? Thanks!
Hi Jason, yes ours is an Arotherm plus, 5 kW. Installation guidelines for this unit are here - professional.vaillant.co.uk/downloads/aproducts/renewables-1/arotherm-plus/arotherm-plus-vwl-35-75-a-s2-installation-operation-manual-0020330791-03-2806789.pdf I suggest our system is installed as per 4.1.1.4 The wall to the rear of the heat pump is a boundary wall, I had not appreciated that property boundary rule and it does look like the system would not meet that rule. Which is not great from our installer...! I guess there is a risk that we need to get planning permission for it, or that a building control officer would tell us to remove it. Although it is at the property boundary, it is 5m+ from the neighbouring property. This may mean it is acceptable...? I am unsure why that rule exists and feel like it could be up for challenging. There is also MCS guidance about distance from openings which feels more reasonable in terms of noise risk. You are definitely into the detail...! Tom
@@TomBray-LowCarbonLifestyle Thanks! Yes - 4.1.1.4 ‘Ground installation in a building corner’ on page 8 requires an overall clearance at ground level of 2600mm wide, 500mm to the right of the unit, and 1000mm to the left of the unit. I’ve watched some of your videos, where you show the unit installed, and you sat or stood by the unit. I don’t see how the space available is 2600mm wide at the base, or 500mm from the right wall, or 1000mm from the left wall? And indeed, the 1000mm government requirement from any boundary under permitted development, which could also cover the wall to the right of the unit? It's not so much being into the detail, it was one of the first things that came to mind when looking at ASHPs, given the strict location requirements for R290 amongst others, which is a fundamental topic. Thanks again!
Your heatpump was free you say so what's not to like then. I work in a similar industry to the heatpump industry and I hear the name Daikin alrtherma mentioned has any body had any breakdowns compressors, electronic PCB yet they cost a fortune,and what I'm seeing the contractors want to replace the whole new system to get you a warranty again. Now compare that to a forty year old cast iron boiler like I have and the only breakdown I've had is a gas valve £80 in the 26 years I've lived there. I pay £112 a month to octopus for gas and electricity for a big old five bed house 13 rads . Any thoughts .
Unfortunately Heatpumps are relatively new tech to the trade and there is not enough expertise out there (like EVs) for detailed repairs especially on electronics issues. Your cast iron gas boiler has cost you way more over the years through inefficiency than a proper expert repair of your heat pump. Same lack of knowledge on modern condensing boilers and domestic appliances in general - new control board mate £££ is the answer you get!
@simoncroft9792 that's the one fan motors £400 X2 PCB for outside alrtherma £800 ,they have become part changers at who's expense. I still think my cast boiler is cheaper. Maybe I'm still waiting for the cheap electric power we have been promised, then I shall get a nice simple electric one .
@@captbarb6642 Sorry to disappoint you but there is never going to be any ‘cheap’ electricity, the Providers are not going to cut their profits and lose out. The government as usual are lying to us. Keep your boiler and wait until the heat pump industry has really matured and there are plenty of installers and engineers who know what they are doing!
There will never be ‘cheap’ electricity! The providers are not going to lose out on their profits and the government are lying to us as usual! Stick with the boiler for now until the industry and servicing support matures and then possibly change. But wait for now.
@@captbarb6642 Your logic is similar to "The Ford Ecoboost engine is a £2k replacement, so be wary of buying a petrol car." Many Heat Pumps come with 5-7 year warranties, beyond that check your home insurance, often up to £1000 is covered for fixing a heating system fault. There was a study in Sweden in 2014 covering 2006-2010 into heat pump reliability by the insurance industry to see where the common faults were and where to improve them. They summarised it with this: To summarise, the installers’ and service technicians’ general opinion about the annual number of failures presented in the failure statistics was; • Heat pump owners are satisfied with their installations. • Not many heat pumps break down in comparison with the number of installed heat pumps in Swedish households. • The heat pumps that break down are mainly old ones, ones installed by the owner or “cheaper” heat pumps not designed for the Nordic climate. • There have been problems with some models of air-to-air heat pumps, which were actually air conditioners designed for the Mediterranean climate that have been sold as heat pumps on the Swedish market. But the number of this type of heat pumps sold has decreased on the Swedish market. • There have been problems with some models of air-to-water heat pumps with insufficient compressor capacity, not suited for the Nordic climate. Nowadays, air-to-water heat pumps are generally equipped with compressors that can deliver the pressure rise needed to heat domestic hot water during the winter. • Failures usually occur on heat pumps in the age range of 5-7 years, and are generally caused by poor installation, improper operation, lack of maintenance or because some of the components have shorter lifetimes than the bulk of the heat pump system itself. • Production defects do occur, but for the heat pump brands that the interviewees install and service, the manufacturers take responsibility for their products and try to solve the problems that arise. The installers and service technicians would not work with brands and manufacturer they do not trust.
Correct me if I’m wrong but with the average length of time folk stay in a house before selling and moving is 8 years and the average usable life of a heat pump around 10 to 15 years, it would be realistic to think that every time you move you’re going to have to install a new heat pump? I was thinking that selling a house with a heat pump would give you a premium but not so certain now :-)
Unsure on the time people spend in a house. A heat pump may well be 10-15 years, which is similar to a gas boiler....? I think it may well give some premium, already been through the effort and expense to install and get working well. Some might want to avoid a house with a heat pump I guess...?
Good video. We've also had a heat pump for 3 years and I've played with the settings a lot too. I've actually turned weather compensation off (controversial) and basically run the heating from 7am-9am and then 11-4pm at 34 degrees flow to 'charge' the house with warmth when the air is warmer outside. Heating SCOP for last 12 months was 3.8. I bump the flow temp up a few degs in colder months but find this actually is more comfortable because allows the house to cool slowly when going to bed. We also have Octopus Cosy so most of my heating is done at 40% discount. Smart tariffs have totally changed the game to running costs.
Do you run the heat pump through the night as well ? Or do you run it just when you are in the house. Did you have bigger radiators installed or did you go with the existing ones?
Hi Carl, sorry for the slow reply, yes, what I have settled on after a few years is to run through the night. And because my wife, or I, tend to work from home most days, we do leave it on all the time. When we go away, I turn the thermostat right down as 'frost protection'. We had radiators upgraded, and 2 added, but the upgrades were to a similar size of the previous installation. I might have asked for bigger radiators in a couple of places if I knew what I know now! Tom
I have the curve on 0.2, really well insulated house and I suspect my heat pump (AroTherm Plus 7kW) is a bit oversized because previously I had it set on 0.35 and it was cycling like crazy (20 minutes on, 20 off). I lowered it, went for aggressive setback temp and now when it runs it runs for 40-60 minutes and then stays off for two hours. Before I had COP 4.1-4.2, now I am hitting 4.5 (heating only, DHW is a different matter - 3.1-3.3)
Well that is really efficient, and much lower heat curve than me. Does sound like the heat pump is too big, which is a shame, but does sound like you are getting much better performance now. Tom
@@TomBray-LowCarbonLifestyle yeah, it might not perform as well when real winter sets in :D I am in Czechia and my location’s coldest temperature (that is used to calculate heat loss) is minus 12C. But these years we rarely hit that kind of cold :)
Hi Graham, we heat our most occupied space to about 20°C, the system can heat to higher but we are comfortable at that temperature. Bedrooms will be slightly lower than that. Thanks Tom
We are an elderly couple who have just moved to a ground floor flat that has air souce heat pump. We are trying to come to grips with this. We have been keeping it on 24/7 at 22 degrees but find this too warm at night. Would be gratfull for suggestions. Opening a window would seem counter intuitive. I have taken to lowering the temp before bed to 19 but from what you have said this is probably not the thing to do. I would welcome any advise you can give.
Ignore @dellawrence4323. It is possible to have a Set Back temperature that you can use for overnight. We have day temperatures of 21 degrees and Set Back of 19 degrees. If you're not sure of the controls maybe contact a local Heat Pump specialist who should walk you through the controls. Our experience of our Heat Pump is that we are paying about 50% of what we would have been using gas.
Hi Jacqueline - sorry I missed your comment last week, I suspect you may be able to control using timings as the other comment said, so the system would be ‘on’ but not trying to get to 22 as you have during the day, we tend to call this ‘set back’ What kind of heat pump do you have? Tom
Hello Tom - I would be interested to know if you think having a heat pump has reduced condensation in your house My thought is a more even and constant temperature in your house would reduce cold spots and subsequent condensation ?
Hi Tom, my heat pump was installed in June, so I’m only starting to use it to heat the house now. When we talk about running 24/7 it can be confusing. The real question is how long is it actually doing something for and when it stops doing something how long does it stop for? I’m trying to understand the optimum setback. From my limited experience when it’s running I get around 0.5 c increase in temperature per hour ( does that sound about right). When it reaches temperature it stops. Now I’ve noticed that the first half hour of running is very energy intensive and then it settles to a less intensive level but still about 75% of the initial half hour, the energy consumption doesn’t drop below that. So to minimise that initial cost it seems to me to require using a much bigger set back temp. Ie the temp at which it carries on again. What do you do and what have you noticed about the energy consumption in that initial half hour compared to the rest of the session. About how many sessions ( or cycles) do you get in a typical day. Thank you for the video. My situation is similar to yours, ie no pv, no batteries. But I haven’t been brave enough to go the agile or cosy route.
Thanks for the video Tom. I have had my 10kW Vaillant Arotherm installed for 3 years as well - this is the first time I have come across this kind of explanation and has really helped me to understand the system a lot more! I have had a fiddle and found my COP over 3 years is about 3.05, and my compesation is set to 1.2. I find the radiators are forever turning on and off so will be playing with this soon to get the more constant running that you suggest! I have solar and 10kWh of batteries so taking advantage of cosy octopus to charge those up 3 times a day and get that reduction in bills as well - once again really appreciate the detailed explanation and honesty - well worth a like and subscribe!
Thanks for being in touch Jon! Good to have you on board! I suspect dropping your compensation curve a bit would improve your COP substantially, and give you less cycling. 1.2 is similar to what I had in our first year. I can imagine with solar, a battery and cost, your bills are pretty low each year. Great to hear from you, would be brill to hear what changes you make and what effect that could have! Tom
If you has the space for it, get more radiators. You problem is that the radiators gets very hot, so the thermostat turns off, and fairly quickly it becomes colder again, so the thermostat turns on again. With more radiators (a higher surface area who can emit heat), the radiators' surface temperature won't fluctuate as much as it's doing today. You can connect them in series, i.e. one thermostat controls e.g. 2 radiators, meaning that the same heating fluid (usually water) flows through the 1st one and thereafter the 2nd.
@ Question on set back temperatures that you might be able to help with. I am now setup on weather comp only - however finding that the system running at night is too warm for me. Should I turn down the set back temp? Does that even affect the unit? Or should I just further reduce the curve value? I guess final option is some smart TRVs in bedrooms
@@jonnutt8999hi Jon - I think you have identified all the options and any of these could be right for you. Turning the weather comp down would be the best for efficiency but may mean you lose out on heat during the day a little. TRV in the bedroom so it doesn’t get too warm could be good. But set back temp, or 1-2° may be all you need… Worth trying each…?!
@@TomBray-LowCarbonLifestyle just reporting back on a bit of progress. WC turned down from 1.2 to 0.4 which for us holds a comfortable 20-21C in the house. This is substantially more comfortable than we were before - where the heating was doing 20C all day but going on and off leading to feeling cold. CoP is excellent now - 4.3 so far in December which has been fairly cold. 4.2 for November overall. In combination with the batteries and cost tarriff my energy cost is down significantly - was £110 for November even with all that heating. I want to say thanks again for the video - your explanation is what drove me to explore this change and I am happier than you can believe! The heat pump was always a source of anxiety for me as I worried about the running costs and so scrimped on the heating - no more! The system is great, thanks so much
I’m just looking into to having one fitted i have a new build house with solar and battery storage. But slightly concerned in the extra cost of electricity as i have to gas broiler running pretty efficiently and we don’t use a great deal of gas and as much as i feel it could be good to have 1 I don’t want it costing me more money.
Hello - I think that is an interesting question, if the house does not need much heat, is it worthwhile installing a new system... from a CO2 perspective, I think the answer will be yes, even small amounts of gas that you burn would have associated CO2 emissions. With solar and battery storage that would help keep costs to run a heat pump very low. If you run your system efficiently already, at low radiator temperatures it could be a heat pump, without many changes internally, is an easy-ish job. If you have space for a hot water tank as well. How much gas do you use each year? Tom
@@Bikebros27 that is very very low! Must be a very well insulated home? Average UK home will be around 12000 kWh per year, so could be 2-3000 kWh per month in Jan / Feb
We've just had a Mitsubishi Ecodan heat pump installed in our 1950s Home last week. Struggling to get to grips with how to control the temperature correctly, as it seems to go either really hot or completely cold instead of a nice steady heat. I'm a bit crap with understanding how these things work. You seem to know your stuff!
Hi Alexander - that’s frustrating! Are you able to get your installer back? What id be suggesting is to get the heat pump onto weather compensation- this video may be helpful? ua-cam.com/video/-983aLzVZ_I/v-deo.htmlsi=IV-taBZ8lFys72xw Tom
@TomBray-LowCarbonLifestyle Thank-you for your reply. I haven't had them back to be honest. I'm having a hard time figuring out the bedtvway to run the heat pump overnight. I'm essentially turning it off as im setting it at 16 degrees. Then in the morning it takes a while to get going again.
Thanks Tom, thanks Esther. You are one of the community of You Tubers who have inspired me to get a heat pump. It was fully installed a week ago. My rational brain tells me my radiators are not hot so I should not be warm but I feel really comfortable. I understand the science behind this but I have lived with gas central heating for so long it is difficult to change my mindset. I opened a bottle of wine to celebrate the day that my gas was turned off. I am still getting to grips with the integration of my Mixergy tank, Eddi, Harvie, Libbi and ASHP. An engineer from Octopus is coming to see me tomorrow to help me. At the moment I have the house too hot 🔥! I haven't worked out the best timing and room temperatures. I have been inspired by so many people on You Tube who have encouraged a 70 year old, widow to take the plunge. I was nervous and frightened of making a mistake but positive feedback from other people encouraged me to go ahead. Early days but I am sure I have made the right decision. I am now saving for an EV. Thank you once again.
Hi Jean, thanks so much for your comment, really encouraging to read! Well done on taking the plunge! It does sound like a complicated system, so I hope the Octopus engineer can help talk you through. It is strange to not feel the very hot radiators but the house still getting warm, takes a little getting used to! Do get in touch if I can help in any way! All the best Tom
FWIW I think you've made an excellent choice. Ignoring the costs or environmental issues, the comfort you feel from the small heat trickling through your radiators is much better than the boom and bust temperature changes you will have previously had. It was a huge leap of faith for us but I am really happy, and more importantly, my wife is really happy with the continuous temperature of the house and the hot water we have. It might take a little while to get the settings just right to get the best efficiency and lowest cost, but once you've done that you can just about forget about it.
I'm 70 now but got an EV 3 years ago, solar panels 2.5 years ago and a heat pump from Octopus this year. They all work well together and we're glad not to be running a cpmbi gas boiler.
Great and very reasonably presented video on the pros and cons of heat pump ownership. We love ours and I'm very happy to say we beat your average unit cost by 2 pence (15.3p) on agile! Keep up the good work of spreading the word and debunking the daft anti-heatpump fake news!
Hi Tom, great video that demonstrates that heat pumps do work in average uk houses. Couple of quick questions, firstly how many radiators did you have to change, what increase in size, and how many throughout do you now have. Also what flow temperature range do operate at and what is the average?
Hi Jonny, good questions... you may have seen I mentioned our system was installed as part of a research project, maybe to maximise their income the contractors doing the install replaced all the radiators with similar ones of similar sizes, we also added two radiators. So, we probably could have coped with just adding two radiators rather than replacing them all. There is a reason to replace them all in terms of ensuring a clean system but not always required. So no real increase in size from our old radiators. We now have 8 rads and a small area of UFH. I don't know the average flow temperature but we use the weather compensation curve of 0.6 - you can see the curve on this page energy-stats.uk/vaillant-arotherm-weather-curve-information/. So our system will be between 30-40°C most of the winter. Hope that is helpful! Tom
That's really interesting Tom because the general consensus is that you need that extra surface area to able to operate at those much reduced flow temperatures. How big and where is your ufh? I think the results you are getting are a good measure of the suitability of heat pumps for most UK homes! you should contact Dale Vince with your findings he currently has been dissing them as not the answer and has the ear of influential people and has an enormous following on social media. Thanks for your reply Jonny
Hi Jonny, sorry for the slow reply - extra surface area means better efficiency but many heat pumps can run at high enough temperatures to cope with fairly normal sized heat pumps, just means we lose out on efficiency. Our UFH is in our extension which is about 20m2. Dale Vince is way too far gone down his 'green' gas rabbit hole, lots of people have tried to explain heat pumps to him over the last few years.... I tend to like what he says but feel like he has a massive blind spot here. I don't have a spec for our rads but they are fairly standard double panel (k2) rads. Thanks Tom
Thanks for the video. Very informative. I have one concern re locating the HP. The only viable location for me would be with the fan blowing cold air over a path. I’m concerned that in winter it might turn a normally wet stretch of path into a treacherous icy spot ready to catch out anyone approaching our house. I wonder if you have any experience of this?
Hi Tim, Good question, and can share my experience of this. Our heat pump is outside our back door, air blowing across the path we use to walk out of the house every day. A couple of things that I have noticed happen when the weather is cold and wet, a) the flow of air keeps the paving dry in the area immediately in front of the fan, b) when it is very wet the cold air does not seem to cause a particularly icey patch, i.e. the air seems to mix quite quickly and the temperature on the floor does not seem to be different to elsewhere Overall, in 3 years, I do not remember a time when there were any issues with ice in this location. Although, as with any management of icey conditions, I imagine we could use salt / grit to help.... Hope that is helpful? Thanks Tom
A person paying £5,500 after grants for a heat pump installation would also pay interest on the money borrowed of around £500 per year, so that wipes out any savings on heating as a new gas boiler can be installed for under £2000. Also UK electricity is generated using up to 60% gas generation especially in calm weather conditions when there is little to no wind.
Hi Alan, thanks for engaging with the video.... would love you to watch this video too on savings... ua-cam.com/video/hYcW65Oz3qI/v-deo.html A heat pump is worth much more than just savings! On average over the last 12 months, the UK got 28.1% of its electricity from gas. But even if we got 100% of our electricity from gas, a heat pump would still use less gas than a gas boiler...! 1 kWh of gas burnt in a gas power station, would deliver about 0.4 kWh of electricity to a home, a heat pump would then deliver 1.2 kWh of heat (at 300% efficiency, often much higher) to a home. 1 kWh of gas burnt in a gas boiler would deliver 0.9 kWh of heat to a home... so if we want to reduce our reliance on gas, we should move to heat pumps asap! AND, fortunately, we get our electricity from a much broader range of sources... You may find - www.mygridgb.co.uk/last-12-months/ helpful Tom
This is a great video, thank you. It also highlights a problem a lot of people are going to have. Which is that a lot, if not the majority, of people won't understand how to improve the efficiency of their heat pump or simply don't want to fiddle with the settings. Meaning their experience is unlikely to be a good one. The other issue is the dynamic pricing. Once everyone starts to charge their EVs and/or use their heat pumps during those currently cheap periods, those won't be cheap periods anymore.
Hello - I was a quite early adopter with our system, and the lessons I have learnt (and thousands of others have learnt with their installations) will mean that many systems will be commissioned / set up with efficiency in mind. Yes it is a fair point about dynamic pricing, if we have smart tech / batteries and charge EV's off peak, that will flatten out the demand and mean prices don't vary as much. But it will also mean we are taking advantage of very cheap electricity when the wind blows and sun shines, so at that stage, electricity costs could be very low indeed. I did a video about that topic a while back too - ua-cam.com/video/eK1ehg5Fv6s/v-deo.html All the best Tom
Thanks, great videos. Shame about the comments that don't seem to get the return on investment, carbon savings and comfort/home improvement points. Got a Vaillant 7kwh myself, installed in September but early days. We are on Cosy having seen that Agile is not so beneficial in the last few low wind months. Both tariffs also aim to encourage load shifting away from the peak demand hours so I tried managing the system myself to bridge the high peak (4-7pm tariff) but an now trying Havenwise who do it remotely using an algorithm to learn your situation to optimise price per kWh heat output. So far price is down 20% on all our electricity (25p to 20p). Cop is 3.0 in recent winter-ish months so not clear if seeking bridging is lowering efficiency but price reduction is encouraging. I reckon we are shifting around 2kwh each day from high peak period (plus more from standard to low). If this was done eventually across say 5 million households then it would avoid the need for one or more gas fired power stations or help achieve the huge increase in clean electricity and transmission that we will need. Thanks again Martin
Like all new technologies it takes a bit of getting used to. Until fairly recently, no one talked about flow temperatures and most boiler installers didn't get it either. It will take time, but someone has to go first, so thanks Tom!
Great video and really interesting comments. We have a modern 4/5 bedroom house and have been quoted £27,000- to install a Heat Pump, (+ another £6,000- for solar panels), the biggest issue being modifying the plumbing and replacing every radiator in every room, so sadly, I don't think we'll be going there, living here in the far SW with poor infrastructure and dire lack of tradespeople. What interests me is the Zero Emissions issue though in respect, for instance, of unceasing and increasing leisure Air Travel; I understand just one of 13 daily BA flights to New York will, for instance, just in the Take Off phase, emit the same gases as my 95% efficient oil boiler will in 10 years, never mind the emissions in the Climb, Cruise, Descent and Landing phases. Just saying!
Octopus Cosy is a very good tariff if used with a small battery. You get 3 off peak periods (4am-7am, 1pm-4pm, 10pm-midnight). With a small (10kwh) battery you can run with almost no use of on-peak power. Note, as off-peak power is generally much less CO2 intensive than the grid average (gas generation is a bigger proportion of generation at peak times than at off peak times) is also greener.
HI Alberto - absolutely! We don't have a battery yet, but cosy can work out very cheap too. I have preferred agile as seems to give more cheaper energy, but you are exactly right, moving away from the peak tends to be lower emissions too, the Octopus smart tariffs are great at incentivising that! Tom
Hi Yorky - you may have seen I mentioned our system was installed as part of a research project, maybe to maximise their income the contractors doing the install replaced all the radiators with similar ones of similar sizes, we also added two radiators. So, we probably could have coped with just adding two radiators rather than replacing them all. There is a reason to replace them all in terms of ensuring a clean system but not always required. So no real increase in size from our old radiators. We now have 8 rads and a small area of UFH. Thanks Tom
Hello yes I am with Octopus which is a 100% renewable energy tariff. In emissions reporting it is good practice to use the average grid carbon intensity rather than assume 100% renewable, so in my calculations I have used the UK average. The grid is getting cleaner and cleaner, and by 2035, if not 2030, there will be very low emissions for a kWh of electricity used for everyone Thanks Tom
Thanks for the information. What is your target temperature at home? Also, don't forget that you are no longer paying a standing charge for gas (assuming that you have disconnected it!). I'm in a 1920's semi in Salisbury (my home town is Carlisle and my family are from Seaham Harbour so I am a bonafide Northern miser); I have about 4kWh of panels and 16kW of battery storage. I still have a combi boiler for heating and hot water but I also have a water tank which feeds into the combi boiler. When the price of electricity drops (I'm on Agile like you) I pre-heat the water in the tank so that the boiler doesn't fire up. Last year my combined electricity and gas was under £300 for the year (I export about £50-60 of electricity a month in the summer). I couldn't really justify the £9k that British Gas quoted for the same heat pump that you have which I really would like. However, Octopus produced a very reasonable quote for a Daiken HP. That said, I am always keen to support UK manufacturing when I can so I opted to wait for the larger Cosy HP to come out (Only 6kw at the moment and I need just under 8 seemingly). Once again, thanks for taking the time to post.
We aim to get to 20°C where we keep our controller, in the room we spend most time in. We actually still have a gas hob so still have standing charge unfortunately, a discussion I have with my wife fairly regularly...! Makes a lot of sense to heat up the tank using low cost agile rates, and well done for getting that far to have quotes for a heat pump and a plan for the future, way further than most people! Good to hear from a Northerner in exile - welcome back at any point! Tom
Thank you for your interesting report. For our well insulated 2 bed bungalow we have solar panels ( no battery), an air duct heat pump and have retained our reasonably efficient gas boiler radiator central heating. The heat pump functions as air conditioning on hot days in summer. We have been reluctant to use it as our main heating in winter because of the difference in price per KwH between gas and electricity. What we lack is an easy way of comparing actual cost in real time. We have deliberately avoided having a smart meter installed but we do have a real time display of solar generation against grid usage. I would value any pointers towards being able to see a real time price comparison of our gas use against electric use.
Many people report high COPs with air to air heat pumps. A COP over 3.6 and it'll be cheaper than gas. ua-cam.com/video/tStlklv1jcE/v-deo.html It'd be interesting to know your costs if you used it instead of gas heating for a month. But I'll not be paying the bill!
I don’t think so - it is mostly unnoticeable. On the coldest days when the heat pump is loudest (not that loud) we and neighbours tend to have our windows and doors closed so not noticeable. I did a video about this here …. How loud are heat pumps? - Low Carbon Lifestyle Episode 38 ua-cam.com/video/ksrAZM-ldI8/v-deo.html
So do you have different temperatures set in different rooms? What happens if you just want the bathrooms heated in the mornings? What happens if you just need heat in one room, say on a cool evening? Cheers.
Hi all - you can control for each room with radiator valves, we don't really do that, just heat all our home, it isn't a massive house. As Biggest-dh1vr says - it can be helpful not to zone a home at all
I’ve done a video to try and answer that … How loud are heat pumps? - Low Carbon Lifestyle Episode 38 ua-cam.com/video/ksrAZM-ldI8/v-deo.html We can’t hear the heat pump inside when it’s on. You can a little on a cold day when you’re stood next to it
Brilliant video Tom! Really good to get some stats from a heat pump in action and I can't wait to get one installed after I (hopefully) buy a house next year.
There is always questions if payback time, seems pointless to me as I'm sure it's increased your property value. No-one every quotes a payback time for a gas boiler, double glazing etc, it'll be interesting to find out if there is any
Unfortunately the general public are NOT tuned in to this technology or have been brainwashed by the fossil fuel sponsored media. The Estate Agents in the Halifax area clearly say that spending £x amount on ASHP, PV or Battery will not add £x to the selling price of my house. I asked what % of £x it might add, and they said “small, if any” !
I would say I am ASHP curious. I have had 3.4Kwp of Solar since early 2012 ( on original very lucrative FIT). I also have a BEV and recently installed 10.5kw of solar batteries. On octopus intelligent go tariff so with batteries most of the electricity I buy is at 7p including charging the car. I generate about 3MW a year from the solar. I have oil boiler so the FIT covers entire running costs of our house (oil+electric). Also have Tado smart heating controls on all radiators so the oil boiler really only burns when a room demands heat. Our house is a 1820’s solid ironstone leaky cottage with double glazing…. Do I take the last leap of faith and pull out the oil boiler and gain back some of our garden when the oil tank goes….. really still sitting on the fence on this one. Great video btw.
Get a quote.. you may be pleasantly surprised.., hitched with solar, batteries and cheap rate it's very low cost I've also taken the gas pipe out on mine.
I always like watching your channel Tom as i live just up (or Down) the road in Hartlepool so it is obviously relevant to me. i have a heat pump being installed by Octopus at the end of this month which after the BUS grant has cost me £900 total. I was quoted by British Gas £7,500 after BUS so Octopus definitely was the best option. I will take your advice and run the heat pump as you suggest so many thanks to you and keep on with the updates. I have solar panels (some of which face north) and a battery and have been pleased with them. I also, like you do not think of pay back because in a way the whole thing has become a bit of a hobby.
Octopus will be installing a system designed to 50c flow which might perform at a SCOP or 3, but if designed to 35 or 40 could be 4. A heat geek - and north east greenhome energy come highly recommended might charge you more upfront but you could earn that back with lower running costs over the years. Worth considering
Thanks Geoff - would be great to hear how your install goes - try and get them to set it up with weather compensation and explain to you how you can alter the settings to push the efficiency up. With panels and a battery I suspect it will be cheap to run whatever happens! Thanks Tom
We built a well insulated woodframe house 11 years ago, used heat pump to meet local green regs on newbuild (a knockdown of a damp 20's house). One electronic fail on heat pump, several issues with tank and especially the complex controls, sensors needed to juggle 35 deg underfloor, upstairs radiators with 60 deg hot water. Would recommend two heat pumps serving each call for heat and minimise the complex controls. May have to do this fairly soon as one of the control modules on pump is now no longer made by Mitsubishi, but expect will get better efficiency pumps. Huge dearth of heat pump engineers to serve existing systems, ours knows how to fix, check pump but needed 4 visits over 6 months to sort issues with periferrals, even though they said system was properly installed. Keep it simple, one pump per heat service, architect we know putting 3 pumps in for a big house in Wimbledon...third one is for AC! Our installer went bust within 3 years, have been told this is quite common, suggests warranty issues kill their margins, not sure how to combat this, especially for older home installations.
I've spoken to two ex-installers. They stopped due to the number of complaints. Whether this is due to the customers not knowing that it's MORE efficient to leave a heat pump running, at a lower temperature, rather than turning it on & off as per gas boiler, or whether it's because of systems failures/initial quirks I don't know. Either way, I couldn't find anyone locally to install, and Octopus won't install (yet) for flats. With winter approaching I've had to give up & go for a boiler to replace the 2 ancient gas fires /sad. A £200 pa saving, for £13,000 outlay is a long RoI, so for most people it's probably still only worth doing if you are doing it for your bit for the environment, despite it benefiting people who work from home, or are retired or on parental leave or are carers, in terms of comfort. I will be getting two MHR mini-ventilators, to reduce heat loss and increase ventilation to reduce the damp issues in the two rooms with inaccessible window openings (bathroom & kitchen).
Getting 13k views in 4 days for a video about heat pumps is pretty impressive in of itself! Thanks for all the information you provide in these videos - hope to get a heat pump soon myself
Renovating/building our house at the moment going the heat pump/heat recovery ventilation combo along with solar panels etc., family of 5 and based in north of Ireland. Looking forward to having the setup and going with as much insulation etc. as possible in the house. These videos set my mind at ease a lot and happy to know it works.
Thanks for commenting Shane, sounds like a great renovation you are doing that will lead to a very low cost and comfortable home! Hope it all goes well Tom
Very interesting video. What sort of temperature do you run your house at? My wife feels "cold" at 22°C We have an oil fired boiler so costs are B I G!
Hi Dave - we keep our most occupied space at about 20/21°C, but that’s our choice, it could be higher if we wanted! My wife is much more comfortable than she used to be because of the constant heat from a heat pump vs the peaks and troughs we had with a boiler. Moving from oil to a heat pump could give good savings Where are you based? Tom
@@TomBray-LowCarbonLifestyle Thanks for the reply. We are based in South Oxfordshire near Wallingford. 1960's bungalow with 15cm insulation in the loft, double glazed throughout and cavity wall insulation installed about 25 years ago.
I'm at 0.5 currently but over night temps have been around 10 degrees c with a low last month of 4 and all good. leave mine on at 20'C room temps and like you I'm using less energy to maintain that. As an experiment I turned the room temps down to 15 degrees for the 10 hours I'm out of the house and my usage went up by 5KW vs leaving it on!! I use 10kw normally so seeing it ramp up 30-50% was a shocker. Like you say they come tuned like a boiler, I think my default install setting was weather correction factor of 1.2!!!! I have the 3.5kw arotherm plus which I had zero faith in coming from an 18kw oil boiler and that wasn't enough on the coldest winter nights in some rooms. I'm running 12 radiators if you include a small one in the airing cupboard and it manages just great. I do have solar panels and 20kw of battery capacity so run Eon drive which gives 7 hours of 9p kw to run the pump at night and charge the battery's. I didn't have this rate on the first year and my electric bills were hitting £200 a month at 34p KW/HR as I didn't charge the battery's over night and solar is maybe 50kw for all of December. This year I think my export earnings will cover November to February costs total! One think I might try this winter if it's cold is using the built in 3kw immersion element to assist hot water I run from 2:30 to 5am if required as a defrost cycle would kill heat output for 30 mins from the radiators. at minus 10 outside you could tell! I've not actually used it once in the 18 months the system has been installed.
Hi Tom, I’m in a very similar situation to yourself I.e. end terraced bungalow, with some new extensions on external walls to current building regs. We’ve had at a Midea heat pump for 2 years now and use the Octopus Agile tariff. The only difference would be that we have underfloor heating for about 3/4 of the house with 3 oversized radiators making up the difference. We also have a wood burner in our main open plan room, kitchen, dining and living room which we love to use in the evenings and heats the whole house when it’s on with half free and half paid for logs. I have tried running the ASHP on all the time based on room stat. But I am finding it 20-40% cheaper to heat the underfloor heating during the second half of the night, when it’s cheaper electric, as warm as I can get it and then switch off at 6am and the house seems to stay warm until at least 4pm with outside temps down to say -3’C. I think this is because the underfloor heating behaves more like a large slow release storage heater. Obviously the heat pump would be switched off to avoid the peak electric costs between 4 and 7pm. So the wood burner is usually lit during this period. I have tried a boost period between 1 and 4pm for the ASHP which probably saves is a couple of hours of wood or even avoid the use of the wood burner in the evening and the daily cleaning and reset ritual which does get tiresome towards the end of the winter. Whenever I’ve tried to run the ASHP on all the time except the 4-7 period I would say it produces heat probably 5-6 times in a 24 hour period and is on for about 1 hour with stat set with a 0.5’C top to bottom heating range. I have 2 on/off programmable periods on my room stat controller. I am trying to take advantage of the, usually, cheaper periods of electric of the Agile tariff, and avoid the expensive periods, which kind of goes against the leave it switched on all the time theory. Do you try and navigate the Agile cost ups and downs or do you just accept the lower average costs?
Tom just runs it low and slow all the time with no battery. I have been trying to dodge the peaks a little (I've only had a heat pump a short time), it helps having a small battery for the 4-7pm period.
Hi Tom, thanks for posting about living in a normal Victorian house. I thought I needed external wall insulation to use a heat pump. Could you post about the location of the heat pump and any noise issues. I have a small garden which is typical of Victoria houses in London.
Hello pmwut - sorry I missed your comment a couple of weeks ago. Additional insulation can definitely help reduce the size of the heat pump and reduce ongoing costs, but not essential. Our heat pump is just outside our back door, noise is not an issue - I did a video about it here - ua-cam.com/video/ksrAZM-ldI8/v-deo.html Terrace houses can be a challenge due to the proximity to neighbours, but a good installer should be able to talk you through all this Thanks Tom
Spead the word! We had a recent Open Green Homes event in bristol. It really good to be able to show what's involved. Give sensible warnings But also reassurance. It's a great way to heat a victorian terrace.
@@TomBray-LowCarbonLifestyle Open Green Homes was run by the Bristol Energy Network. I think it started as a national thing. But they carried it on locally. There is 'visit a heat pump' run by Nesta which is national. There used to be a scheme called super homes too but not sure if it still runs.
Hi Tom, thinking of a heat pump, i get scop but to achieve a high scop you need to run the heat pump all the time which I understand but me and my wife work long hours so i only heat house 4-5 hours a day on gas so will i need more energy if running all the time then using combi. As for solar i have a great 7kwh system battery on a perfectly south roof. Great till october now when you'd need it run the heat pump I don't get enough power the toaster, well exaggeration but most cloudy days I'm not getting enough run the house as is. Wouldn't change the panels they are great best investment i made with the battery but the point at which i generate extra energy consistently to power the heat pump will probably be the point i turn the heating off. Just one to think on when doing the maths, you can't offset total energy generated from energy used by heat pump.
Hi David, yes this is potentially an issue for a few people, and although imperfect, I think a heat pump can still be suitable. Although there is a saving in switching off heating when you are out, the overall energy required to get to a comfortable temperature is similar to if you kept the house at a constant temperature (it will depend on the house and external temperature etc). So running a heat pump 24-7, or at a set back temperature 1-2 degrees below what you want it when you are back from work, would deliver slightly more heat than your gas boiler, but use a lot less energy. And if that means maximising the efficiency of the heat pump, that will be a low cost way to heat a home. We used to heat our house like you describe, only running a gas boiler for a few hours a day, but we still used 12,000+ kWh of gas. Moving to 24-7 heating with an efficient heat pump, means we are using less than 4000 kWh of electricity. It is a change of culture / thinking rather than particularly wasteful way to heat. I need to do a video about this, as I am not sure I articulate myself well in comments!! And it is counter-intuitive / nuanced... And yes, solar and heat pumps are imperfect, but October / March / April does get some generation that helps support a heat pump, and the summer months, hot water can be more or less free. Overall, your costs would be meaningfully lower coupling the three technologies, and even lower if adding in a smart tariff. Thanks for sharing your thoughts!! Tom
Thanks for this Ive looked and looked at heat pumps. In highland scotland 1800 on lpg it was exactly what i wanted however discovered concrete floors and did nt have budget to take them out got company in to quote they couldnt answer my questions and totally ignored my concerns over where pipes would be...they wanted to surface mount everything .. .Ive got 2 woodburners and my sudden health issues making me rethink AGAIN lol...is there a video about ur installation so i can see what issues you had ...thanks
Hi Fiona - that sounds like you’ve had a frustrating time. Hopefully you’ll be able to navigate it this time around. Not sure if this video (the first one I did after our installation) would be helpful…? ua-cam.com/video/ZXNWuAK87SE/v-deo.htmlsi=YjxNA14d_V6c42U1 Do come back with any questions Thanks Tom
Hi Tom does your system still have hydraulic separation (buffer tank extra circulation pump) I seem to remember seeing one in a previous video. Have you investigated going open zone re plumbing the buffer tank into a volumiser on the return and running purely off the circulation inside the outside unit? It should improve the efficiency of the system unless there’s some specific need for the hydraulic separation such as micro bore pipe work
Hi Ed - yes we still have the buffer in place, and we haven't looked into removing it yet - I am conscious that others have done this with videos on youtube, not been a priority for me yet! But something we could do in the future. Would be great to free up that space the buffer takes up at the moment. I have a service coming up from a Vaillant engineer, could be something we chat through then Tom
6:04 The curve is very interesting as 0.4 means quite cool radiators a lot of the time, e.g. 10C in the day and 5C at night the flow goes between about 30C and 35C. Something must be on/off cycling, as wind and sunshine, people and appliances, affect the heating demand very much, at the same temperature. Haven't heard of variable flow CH circuit circulating pumps.
Hi Plinble - not sure what you mean here, the weather compensation curve means that flow temperature within the heating circuit varies with external temperature, and yes it can be as low as 30°C when there is not a significant heat load. This is not a variable flow central heating system, but a variable temperature system. Tom
@@TomBray-LowCarbonLifestyle the main meaning is that external temperature by itself is too simple, there are other factors. Also on the pump side regarding the wind and relative humidity, e.g. making condensation should be getting you free energy.
@@plinble Hello - weather compensation control is a common way of controlling heating systems. Yes there are variables that impact on this, but it tends to work well for us. You could also have room compensation, i.e. flow temperature changes with room temperature, this is analogous to external temperature but would include other factors such as cooking occupancy etc.
Hi, Solar doesn’t help run a heat pump directly as the main generation is in summer. However, if you use the octopus export rate of 8p or 15p then you can use summer credits to pay for the winter heating. I have solar/battery and ripple shares alongside an EV and export as much as possible at 15p. This means I am approaching zero electric bill.. not there yet but I am down around £30 per month and still falling as these strategies unfold. I was paying £150 electric and £100 diesel so the electric switch can be much cheaper.
Hi Pmac - absolutely, the best time for a solar + heat pump system is now, still longish days but into the heating season. In the depths of winter solar doesn't support much. Sounds like you are making some good steps with your system, we have some Ripple shares, but no solar, battery or EV yet, one day!
Great video Tom (and Esther..). We've just signed up to have ours installed by Octopus and just waiting for a date now. It's been reassuring watching and reading all the positive feedback about ASHP systems, especially from people that have used them for several years now. With solar and batteries and the Octopus Intelligent tariff we're hoping for some decent savings, as well as helping reduce emissions. Keep up the good work..!
Fantastic, hope the installation goes well, well done for getting this far!! And yes, with solar, batteries and a smart tariff, I suspect your costs over the whole year could be very low! All the best Tom
@@TomBray-LowCarbonLifestyle Hi Tom - That seems to be the temperature that most people run their systems at. As I am in my latter years I find I need a minimum of 22 to feel comfortable. I guess that would increase the energy cost quite a bit.
@@paulcolu It depends on how you heat your home. If yours is the traditional way of having a thermostat that turns the boiler on and off then it will typically be set higher than the comfortable temperature. Stable State heating (which is common with heat pumps, but also doable with some gas boilers, but rarely implemented in the UK), will continually put in the same amount of heat as is being lost. Those that have switched from thermostat-controlled to stable state heating have found using the same temperature as before was too hot, and have had to turn it down a few degrees.
I have solar + battery and am moving on to a heat pump this year 🤞What I've found is that we're not really using much solar generation over the heating season, because it's heavily stacked towards the summer months - around 10x more generation on a summer's day compared to winter. You're really relying on a good feed in tariff (15p/kwh from octopus) to make an effect on your bill. That said, you're likely to see massive benefits from the battery by charging up during cheap times on Agile or another time of use tariff.
Yeah absolutely, solar + a heat pump would be an imperfect pair, but whatever generation you can get can help supplement heat pump costs. This time of the year when we still have some daylight but also are heating is great, but peak heat and low of generation in december and january is frustrating. Hope your heat pump journey goes well!! Tom
We had our heat pump installation in June. Straight away we got hot water powered by electricity from our solar panels rather than burning gas. So that was an instant saving. Now in autumn a proportion of our heat pump running comes from the solar panels... admittedly not a big proportion. Exports will help but with an ev we don't export so much - just over £100 worth. But we aren't buying petrol or gas and have no standing charge for gas. I'd say solar, hp and ev work well together. @@TomBray-LowCarbonLifestyle
Great video. I too have been on journey over 4 years... now runnng on weather compensation... in an old listed building with modern extension. Works great. We have solar and batteries. Use Agile import and fixed export 15p. Its complicated to do the maths on solar & batteries! Remember most production will be in summer so more likely to export higher proportion. Using tech to fill batteries at cheapest slots and minimise peak Agile. I only moved from Tracker to Agile in last year. Import cost averaging under 11p. I'm optimistic even with winter usage we'll average under 15p. With increased offset of exports as im importing more cheaply at night.
Hello Tom. My disabled daughter and her family moved into a housing association property where a new heat pump was installed(there was an existing pump that was defunct as they moved in) They were given no instructions, about how the system worked, or how to control settings for efficiency,,they have solar panels no idea if they have a battery, and I've been trying to obtain for them basic understanding on how it all works, your video has really helped, any ideas where I can gain education for them, noone from their housing will come out, they just say in the winter leave the system on constant, - any basic advice would be really appreciated. Thanks again
Hi Angela - where are you based? If the home is warm and hot water is ok it may be worth just leaving it as it is. There may be some optimising to do on efficiency - what manufacturer of heat pump is it? There may be some good guides online / on UA-cam that could help with the specific system I would be happy to try and help via the phone but can’t guarantee I’ll be able to!!
@@TomBray-LowCarbonLifestyle hi tom, we,re in ipswich.suffolk. we are clueless, haven't been given info.just moved them into this property, no hot water when they got there ,then informed s new heat pump system was measured up for and installed, we dont even know if this time of year the heating part has to be put on and left day and night, let alone how to adjust it. For optimal efficiency and cost I think I will have to pay for a technician to come and give us education and confidence to ,' try it all and see' as the housing association are not providing tenant guidance, thankyou for your kind offer, until I get a technician would you suggest putting the heating button on and leaving for a week and see what we experience. My daughter has no income, disabled and on benefits and being uneducated about cost and operation is of course of greater concern. Your video was very useful thanks
Hi Angela - do you know what brand of heat pump it is? Leaving the system ‘on’ to heat to the desired temperature on the thermostat could be fine, although this could be expensive if not set up with weather compensation. Until you get a technician out, I suggest using the system as you would any heating system, ie on when you want heat and off when not Sorry I am not nearby otherwise I’d be happy to visit!!! Tom
@@TomBray-LowCarbonLifestyle thanks for trying tom, just insane this sanctuary housing not educating us, and not willing to send their 1 regional heat pump tec hnician out who fitted it or provide paperwork. It's a brand new Mitsubishi pump,and I will find an independent technician. Many thanks again
A Victorian terrace, with double glazing and loft insulation and suspended floors, not sure it’s that well insulated. Piping was new when the boiler was put in before we moved in. What would you call average?
An in depth analysis, especially to do with the pricing of the supply. It’s probably early yet, but there must be an element of maintenance for the equipment? My place does not use water central heating, but I’m used to both solar thermal and PV in tandem, being half way through the old feed-in tariff. No local electricity storage, just exporting the surplus. Depending on you use of warm water, it might be worth considering the use of thermal tubes on the roof, as long as there is enough space for a 300l or so storage tank, if it’s compatible with a heat pump alongside.
Hi John - we had maintenance included as part of the installation for the first two years. And have just booked in service for the 3rd year for just over £200. Hoping to do a video as to everything involved! I think one day we will install solar PV that will help power the home, heat pump and future EV, I think adding solar thermal would add too much complexity to the heating system, but could be good for some. How do you heat without central heating?
@@TomBray-LowCarbonLifestyle My place is on the E7 tariff, and there is a mixture of storage heaters, simple electric heaters timed to night rate, a balance flu gas fire, and night rate water storage heating (to top up the solar thermal when required). It’s a small house, built with a heavy concrete block structure (which is an automatic storage heater, and keeps cool in hot days).
Just started to look at heat pumps and just have 2 questions. Once your on the heat pumps did you you have your gas supply switched off and if so do you still have to pay for gas as a standing charge. Secondly once everyone is on heat, how will the government claw back the lost revenue, increase the price of the electricity supply 🤔
Hi Darren, We have actually kept our gas supply as we still have a gas hob, so paying the ~£180 per year for a very small supply! If we switched to electric / induction, we could remove the gas meter and save on the standing charge. What lost revenue are you referring to? Currently gas bills are subsidised when compared to electricity bills, for gas about 6% of the costs are taxes or levies, whereas electricity, around 30% of the costs are. So there could be a change in revenue for government as we would use a lot less energy, but the energy we do use has a higher income for the exchequer. The bigger change will be electrification of cars, because fuel duty is a massive money raiser for government. Final point to add, one of the reasons fuel / energy is taxed, is because they are damaging to people and the environment. If we burn less gas, and less fuel, our air will be cleaner, we will have less issues linked to lung disease and a lower NHS bill (for example).... Thanks for engaging with the video Tom
Solar panels primarily produce during summer and you primarily need heat during winter. I’m from Denmark, so I guess heating need and solar hours per month are pretty similar. Last year we had ~40 hours of sun in December (according to various weather reports) Wind is generally a better source for ‘heating electricity’ and I guess you can get most of that benefit from your flexible tariffs by increasing/decreasing the setpoint for the heat pump output water… I don’t know if your heat pump supports that kind of logic, but it’s not impossible nowadays
Hello - completely agree, and I don't think I say the contrary of that in the video, I say that solar panels can help supplement costs, particularly in the Autumn and Spring, but definitely don't power the heat pump on their own. Tom
Yeah there are tariffs for cheaper elec during windy days eg octopus intelligent and my experience so far this year is that there are more windy days (and nights) due to climate change in northern Europe. This not only makes heating cheaper but the whole house, plus charging an ev and batteries, thus extending the cheap time period. Solar is a bonus for 8 months of the year..
I got 4.7kWp solar with a 3.6kW inverter installed two years ago and I'm generating around 4000 kWh per year. The warmer months tend to be best for generation, so how it would work for a heat pump really is to get a good tariff that pays well for solar (Octopus Flux is a possibility - that's what I'm on and is intended for solar/battery owners; I do have a bidirectional car charger as well which is quite rare in the UK but it does the job) which would offset your winter bills. There is some generation during the winter but it's not a huge amount, though it probably tends to happen on colder days when you need more of the energy for heating so it may work out well. I'm seriously considering a heat pump upgrade now. My boiler is 10 years old and whilst a lot of people would say that it's likely to be coming to the end of its useful life, I don't accept the 10-15 year life that is commonly mooted for boilers; my previous house had a boiler installed in 1999 and it's still working fine, although it's not been anywhere near as reliable as my current boiler. Also I found out about opentherm and started using that around two years ago to allow the boiler to modulate and run more often in condensing mode. I have a 1952-build terraced three-bedroom property and a nest thermostat to control it, set to 18.5C during the day, and I have averaged 6455 kWh of gas per year over the last two years to heat my home and provide hot water. I've learnt a lot from youtubers like you over the past week or so as I now have a quote from Octopus for a heat pump of around £3300 after the £7500 grant, though I do need some extras like a solid base for the heat pump to go on, and the survey hasn't been done yet. It seems like a major part of getting efficiency from heat pumps is running them nearly all the time. If I may, do you vary your set temperature at all to take advantage of lower-cost energy periods? I see Octopus do a Cosy tariff that provides eight hours of low-cost energy at three different time of the day and I'm trying to gauge whether it's worthwhile to heat more during those times (perhaps by raising the set point by one degree or so) and have it back off during other times; the overall efficiency would obviously be a bit lower, but it might be cheaper to run as a result. (Whilst as I said I have a battery system through my EV and could charge my battery during those times and probably would, but I think the round-trip efficiency is only about 78% for using that to power the house, and that was installed as part of a trial and cannot be replaced with a like-for-like system if it goes wrong.)
Tom uses the Agile tariff, rather than Cosy, as do I. Some flexing around peak costs is possible on Agile. Solar is great to defray the winter costs of the heat pump, generating credit in the summer on the 15p fixed outgoing tariff before the expensive heating of the winter.
@@justinjoanknecht3475 I was lucky. About 3-4 years ago I applied for and was accepted to a trial that involved my normal charger being replaced by the one I have now (a quasar wallbox) and I paid £250 to keep it at the end of the trial.
The longer the heat pump in direct sunlight the more energy efficient the system will be even in freezing sunny conditions. Easy installation isn’t always the best position for efficiency. You may face extra charges if the location make installation longer but higher efficiency long term will pay for itself.
There isn't a huge difference, Heat Geek did a test with using mirrors to direct more sunlight onto the coils, and it gave about a 5% improvement in the summer. Given nobody is going to have mirrors around their heat pump, and the sun is lower in the sky in winter, along with not being able to have the rear of the heat pump facing the sun all the time, the difference will be very negligible.
Is that not when you have it on adaptive controls? If it is pure weather compensation the heat curve would be doing the same thing house to house...? I may be misunderstanding!
Great video. Thank you. I've had a heat pump for 4 years. This is what I've learnt in order of importance for cost savings:
1) Reduce flow temperature as low as possible that still allows the house to heat up from offset temperature (say 17 degrees in my case) to comfortable living temperature (say 19-20 in my case) in a time reasonable for you. There's little point in setting it so low that it takes 6 hours to raise temperature 2 degrees.
2) Lower hot water temperature as far as you can and don't have the heat pump heating water all day. Use the timer to heat the tank for a given 'bath/shower' period only: it's far cheaper if you can agree to shower/bath just in the evening or just in the morning. I have a family of 5 which makes this difficult to say the least.
@@A.P.Garland Sure, but it would be helpful to have cop data for the winter months alone. Most of us don't run - and can't afford to run - central heating boilers throughout the year.
@anonanon289 I've never been able to gather and plot accurate COP data for my ASHP. Needless to say, when it's -5C outside for days on end and I have weather compensation on (flow temperature increases as outside temperature decreases) COP is horrendous. When it's warm enough outside not to even need the heating on, COP is brilliant, but never leveraged because the unit is off.
Wasn't it a very mild winter last year? How much does that affect the stats?
It depends on what metric you use I guess. If we look at www.degreedays.net/# at my local weather station, in winter 21/22 (Nov-March) there were 1434 degree days, 22/23 = 1489, 23/24 =1471.
Degree days give a metric of how long and how far below a certain point the temperature was, so therefore how much heat was needed. This year, slightly less heat needed than the year before, which was quite a bit more than the year before that. It may be that the last three winters have been warm, although the met office said this January was 0.1°C lower than the long term average.
Anyway... yes weather impacts on performance of a heat pump, I have done some videos specifically about heat pump performance over winter here for January - ua-cam.com/video/GmsMV6ApwO4/v-deo.html and here for the whole of winter - ua-cam.com/video/FnVsfbL4owQ/v-deo.html
If we have a particularly cold winter, heat pump performance will drop, maybe by 10% (my estimate) but all dependent on temperature
Tom
We got 5kW aeroTHERM plus installed in August and have been tweaking various elements to see we can optimize efficiency and comfort. Still too early for any proper conclusions. The weather compensation curve was set to 0.7 when it was installed, but I've dialed this down to 0.5. First full month was September and we achieved a COP 4.0, with more heating in the mix this month we're seeing an average of 4.4.
House is noticeably more comfortable with a consistent temperature than our old gas combi-boiler where the rooms were either too warm or too cold, and rarely just right. This combi-boiler was 24 years old so would have been lucky to be 75% efficient, so I expect we're now using less than a 1/5th the energy we used to for heating.
We have requested Octopus to come and remove the Gas meter, once that is gone we'll save a roughly £100/year on standing charge. Often folks talk about gas vs heat-pump costs per kWh of heat but don't factor in the standing charge, with this saving you don't actually need to achieve the as high COP to break even.
At the same time as installing the heat-pump we got 2.8kW solar and 15kWh of battery installed, in September in generated a 207kWh which was more comfortably more than the 134kWh consumed by the heat-pump for hot water and space heating. We still needed to pull an average 4kWh/day from the grid, but this is way down from 25kWh we would have consumed of Gas and Electricity in a typical September. I'd expect in the June and July we should be mostly off grid.
Hi Tom, thank you for the great video. I would like to know what your temperature settings are and also how do you change them in relation to Octopus Agile tarrifs? For example, what time and what temperature is your setback, or what time do you heat your water? How does your daily schedule look like? We had our heat pump installed in June, and this is our first week using the heating. I am looking for some ideas on how people are using the settings to increase efficiency. Many thanks! 😊
I'm still in the initial testing stage, but am trying 20 degrees until 9am, then 21 degrees all day, with slight increase in temp to 21.5 degrees between 3 and 4pm, before the 4 to 7pm to reduce use during that period. Setback is currently 18, but likely to increase.
Two periods of hot water heating- 03:00 'til 04:00 and 13:30 until 15:00.
Hello - thanks for the comment - temperature settings keep the house at a constant temperature so 20°C 24-7. We don't change them related to the agile tariffs. Although I should note, the thermostat is in a room and external sensors for the weather compensation control are both south west facing, so our heat pump tends to run less hard during the 4-7pm peak because of our specific set up.
We don't have a set back overnight.
Heating water - we have the system to run outside of the 4-7pm peak, if the temperature in the tank drops by 5°C it comes on to heat the hot water. Which can happen in any of the 21 hours outside the peak.
My conclusion, particularly for heating settings, is to try to push the weather compensation curve as low as possible and leave the heating to run as long as possible. This has led me to ignore any time settings, even with octopus agile. I am happy with this and means the house is always comfortable.
I started with a set back of 17°C overnight, but this also tends to be when electricity is cheapest, so it didn't really make sense not to use the heating system with cheap electricity. Slowly and surely I reduced set back, until simplifying the system to run constantly.
Others may come to different conclusions!
Hope that is helpful?!
Tom
@@TomBray-LowCarbonLifestyle Surely it would be a lot more efficient to heat the hot water once a day while the air is warmest and electric cheapest - at 13:00-16:00? I do the same thing with my gas boiler for DHW only. Once we've had a shower in the morning I don't care if the temp drops a bit throughout the day and it's got to be more efficient to heat up once from 40°C than constantly trying to get it from 55° to 60° ...or whatever.
@@johnhunter4181 That is a fair point John, and something I will have a think about! First thought is on cost of electricity during the day and whether it tends to be cheaper overnight....
This is my 2nd winter with a heat pump. No solar, no battery. I have my setback temp at 18°c and target of 20°c to 21°c. I pay £130 a month and currently on a fixed tariff from eon next which is cheaper per unit than the price cap.
I have my heat pump on schedules, 7:30am to 11am and then 17:30 to 11pm. Not sure if this is the right thing to be doing, but there's no big fluctuations in the temperature. And if I do feel it when it's out of schedule running then I click up the thermostat a degree or 2. Then it just runs when it needs to.
That sounds good if it works for you! My only thought would be to increase the set back temperature slightly, and push the flow temperature / weather compensation curve down slightly, might get a little more efficiency out of the system and cut costs slightly
But, if you’re happy, maybe not worth tinkering!
@TomBray-LowCarbonLifestyle I've had a look at the weather comp curve and it shows at -3°c the flow would be 45°c so what you're suggesting is to increase the set back temp to say 20°c and my target temp to say 22°c but lower the curve flow slightly to say 40°c ? If I am understanding you correctly Tom?
I've got solar, heat pump and a battery in a 1970s house. It's a big outlay and this will be our first full winter, but the Cop is hovering around 4.7 with weather compensation on 24/7 and we've turned off the gas, so no gas standing charge. Octoplus tariff gives us 3 hours of cheap electricity at night, so that tops up the battery. So far so good.
Sounds great Ian! And really efficient heat pump so far, will drop a bit with colder weather but 4.7 is very high!
What make you think you have a COP of 4.7...??
@manoo422 Vaillant app
@@manoo422 What makes you think he doesn't? Vaillant ones give the COP figure in the app, which some have confirmed to being close to accurate with external measurements (open energy monitor). A COP of 4.7 for this time of year isn't exactly a stretch. Check heatpumpmonitor with limiting to the past 7 days, about half of the 185 listed have achieved a COP of over 5.
@@BenIsInSweden The fact you would believe the heat pumps figure is laughable...I have some gold mine share you would be very interested in...
Do you still use gas i.e. for cooking.
If not and you only use electricity, do you only have one standing charge to pay, i.e. you don't pay the gas standing charge?
What sort of price would I be looking for the heat pump and all the radiators to be installed in a two bed terrace house?
Good question - average cost is about £13k, so yours may be a bit smaller / cheaper than average. So £10-12k?
And then after the grant, between £2.5-4.5k…?
Although someone like Octopus may be cheaper, and some installers may be much more expensive!!
Tom
@TomBray-LowCarbonLifestyle thanks tom.
0.6 here. Great to hear more about your own experience 👍
Very generous of you to the gas boiler.
Thanks for the shout-out! 😊
Thanks mate - and thanks again for the Mic!
Thanks for the honest comparison.
I'm on octopus agile. The prices shoot up between say 4 and 7 pm (as you would expect).
How do you get around this with your heat pump? Does it just switch off between 4 and 7? And if so, doesn't the house get cold during those times?
Hi Philip, good question, I actually tend to just leave the heat pump running during the peak time, in an attempt to keep the weather compensation curve as low as possible. But program hot water and anything else that can be delayed (washing, washing machine etc) to outside the peak times.
As the peak is only 3 hours, the average is brought down by the lower cost 21 hours, so for most of the year (except 1/2 days) my average rate has been much lower than a price cap rate, without really changing behaviour significantly.
You could program the heat pump with a set back rate for 4-7 but I have not done that.
Hope that is helpful!
Tom
@TomBray-LowCarbonLifestyle great, thanks for the reply!
How do you decide the size for the heat-pump.? I’ve been looking at the aerotherm + for a 3 bed terrace of which we have added 50mm cello Tex to all external walls , with rear having 100mm cavity on lower ground.
Hello - that would tend to be a calculation done by your installer based on heat loss of your home.
I have done a video about the steps to getting a heat pump here ua-cam.com/video/nbaAibu0EgM/v-deo.htmlsi=GSq6_moiS6zDU2w_
This includes some thoughts on heat pump sizing
Thanks
Tom
Q. what about noise? Is it intrusive in the summer?
Also what was the typical room temperature?
Hello! I did a video about noise here - How loud are heat pumps? - Low Carbon Lifestyle Episode 38
ua-cam.com/video/ksrAZM-ldI8/v-deo.html
We don’t really notice it in summer, partly because it is rarely running and when it is running, it’s fairly subtle.
We set our most occupied space to about 21°C but other rooms in the house are a bit lower.
Thanks for engaging with the video!
Tom
Is this MCS certified? Just looking at the thumb nail seems it seems to exceed the reflective surface limit (max allowed is 3) anything within 1m on the unit. Floor always counts as one, back wall would be 2 that leaves left or right of the unit only, both left and right seem to have a wall within 1M so wouldn’t that count as 4 reflective surfaces? Not to mention clearances for servicing/maintenance and door within the protective zone. However may just be the camera angle
Hello - yes it is MCS certified, so I am interested to read your comment, although the wall on the left is more than 1m away from the heat pump.
The clearances are ok on each side except the right hand side, which is too close when considering the manufacturers guidance. However we just had a vaillant service and the engineer said it was not a problem.
Although you are right to point out these things, I guess having a bit of flexibility to install in tight spaces will mean installations can go in more homes. I wonder whether MCS needs to have more flexibility in the future...?
Hi, what is the known reliability, expected lifespan, and replacement cost of your heat pump?
Hi Mustang - good questions - reliability, nothing gone wrong in 3 years with the heat pump, I’ll let you know when something does.
Lifespan, Google suggests 15-25 years, similar to a gas boiler if not better.
Replacement cost, not sure, the heat pump itself is not particularly expensive.
Thanks
Tom
Hi tom just wanted if I can to get your view.
We had a heat pump fitted by global energy in sept 2024. It has a weather compensation system that varys according to the outdoor temp. This system can be navigated and adjusted by the company at their end.
I recently rang them to ask could they check over the settings. They did and assured me its set at the most efficient.
Its set at Upper AT heat 15 degrees.
Lower AT heat 5 degrees.
Upper WT heat 55 degrees
Lower WT heat 34 degrees.
Water temp 48 degrees.
We run the heat pump 24/7 set room temp at 20 degrees.
21 degrees from 5.30 pm to 10pm.
We are using on average 20 kw per day we are all electric with no solar panels.
My question is with the experience you have obtained. Do you think that amount of usage is right. Which will only increase now as the weather gets colder. Thanks peter
Hi Peter, it is difficult to estimate how much a system should be using because I am not sure of the size of your home, age, insulation or location etc....
But I think the settings may seem a bit high...? For my system, the highest water temperature when -5 outside will be around 45°C, at 15°C outside the water temperature will be at about 25°C. So I suggest the weather compensation curve could be lowered slightly.
We have used about 13 kWh per day so far in October / November this year for the heat pump + 3-5 kWh for other electrical loads.
Hope that is helpful
Tom
Thanks tom. We live in a 3 bed detached stone built property which has had all external walls insulated . We are in northwest NR. Southport. To give you an idea. Yesterday Sunday 17th Nov we used 39 KWH.. Which to me seems excessive. But I'm not sure
Your flow temps are way too high for efficient operation. You need to be running at a max of around 40c and a min less than 30c to get good efficiency, but I don't know if that would keep your house warm enough. Ours is on weather compensation at a max of 38c and a min of 26c, so our max flow temp is almost as low as your minimum
Thanks for your reply David. I've checked back with my installers and they assure me my settings are set at the most efficient it can run. So don't know. It's not as if I can argue with them as I'm only learning myself about how the system runs
Great video. Out of interest, how do you carry out the electric and heat metering on your system? We're shortly installing a Kensa ground source heat pump and I would like to keep logs of the data to calculate COP. Do you monitor the temperature in your hot water tank and if so how?
The vaillant App gives the data in Tom's case I believe. There are also 3rd party monitoring tools from open energy monitor that your installer can fit for you. The kit is pretty expensive ~£600-£800 if I recall, but generally worth it as it logs the data in real time, so can help spot issues etc.
Does this system also work to cool in the summer?
I understand it can, but we do not have it set up in that manner. Cold water in radiators leads to condensation and pools of water under radiators. So not ideal…!
Just a had a 6kw aira heat pump installed yesterday with all radiators replaced with bigger ones. DNO request now pending for a 6kw solar system. Also have an ev so will be looking to investigate best tarrif options
That’s fantastic Scott! Sounds like you are making some significant steps that will have a big impact!
@TomBray-LowCarbonLifestyle hoping so with the aira system they claim to monitor everything remotely and make adjustments. I have already turned to water temp down to 50c as the hot water is extremely hot when set at 55c. Also an option to program heating the water tank during off peak hours with octopus go but says this will swith off the intelligent monitoring. Will need to investigate further 👍
We've had our heatpump for three month now and also my wife praised the heat to be 'more comfortable' now. Also from what I can tell already we'll not be reaching the amount of costs we had with our oil boiler. Also very interesting to hear the installation costs in England. Here in Germany, I paid double the price you paid for yours (26000€), I wonder why that is. I got back 9000€ from the government though.
How much damage did the install cause,eg redecoration costs,pipe boxing etc etc
We lost some storage space, and there was one floor board that was slightly damaged, but not much to write home about.
Thanks Tom for another great video. My 7kW Vaillant Arotherm+ has been in about 3 months, and is working well. It'll be even better when the ground floor is insulated, hopefully before too long. Otherwise a mish-mash of IWI, 30yo cavity wall insulation, extensions with 2000s insulation and an uninsulated hard-to-fill cavity wall. Mainly double glazed but with two triple glazed bay windows. Curve currently set to 0.5, lower than design flow temp of 45 degrees at -3, but expect to increase to 0.6 at least when weather gets colder, and while ground floor is still draughty.
Unlike you Tom, my journey started with making my gas boiler behave as much llike a heat pump as possible with flow temp reduced to 50 degrees, running 24/7 with overnight setback of a couple of degrees. I learnt as much as I could before taking the plunge with a Heat Geek install. Chose design target temp of 18, and planning on upgrading more windows and insulating/improving insulation of roof spaces over the next few years to improve comfort and get temps to 19 at no extra cost. Roof not really suitable for solar PV, and no battery, but Octopus Agile tariff is saving me around 10% compared to the Flexible tariff. The gas meter was removed a month ago, so also saving on standing charges.
I didn't really think much about the hot water side of things until well into the design when Heat Geek swapped in the Newark at a much higher cost. I haven't been too concerned with payback times but with my low hot water use it would have taken decades to recoup additional cost of the Newark cylinder so I asked for the Vaillant hot water tank to be reinstated. It might be less efficient, but energy used to heat water to 50 degrees over last 3 months has averaged about 0.7kWh/day.
Will be another 9 months before I have electricity costs for a whole year, so far too early to say whether I'm saving any money.
Thanks for taking the time to comment, I am pleased that you have had a good experience so far, and hope it continues when the weather gets colder. You may find that the 0.5 curve is sufficient, but little harm in changing it if needed!
Look forward to hearing how you get on this winter
Tom
Live in a village so 100% electric, no gas line. Our heat source pump is over 7 years old as that’s how long we have lived in this house. I think it is too small and our electric bill is over £400 a month in winter and will probably be a lot more this year. I find it takes a long time to heat a house, so heating on about 19 C when out and turn it up when home. Since living with this system I have never felt warm in winter.
Hello m0ther0ne - thanks for sharing your story, there may be some settings you can change to improve comfort and reduce costs. A 7+ year old system should still be working ok, but may benefit from some maintenance.
My home would be about £250-£300 in December and January. You say it takes too long to heat a house, that may be an issue with your heating approach, mine also takes a long time to heat up, but can easily maintain comfortable temperatures. What temperature are you hoping to achieve? Do you spend long periods away from home? It could be worth leaving the system at a higher temperature when you go out so that it can maintain that temperature when you want it...?
Sorry that you haven't felt warm in winter but hope things can be better!
If your heat pump uses air on the outside unit, I would clean the air part of it. If the unit's air part is dirty, it can extract less heat compared to when it's clean.
Like the comments below, it may well be more about how you use it than anything else. Heat pumps work nothing like gas or oil systems, with much lower water temps in the rads. This needs larger rads, and the whole system needs setting up well. Never turn the pump off, use all the rads (the heat pump should be sized to the volume of water in the whole rad loop), and modulate temperatures with weather compensation. If your system has this it may be turned off, or the sensor may never have been fitted, or linked if one has been. Some installers don't understand much about many aspects of heat pump installation and use. If you want 21 C for general living, don't drop the night temp to less than 18 C. It uses more energy to regain temps than maintaining them. This is true even if you have terrible insulation values. If insulation values are poor, there isn't much more you can do to make a heat pump perform well. Using the fabric of the building as a heat sink is also important. My modest 1980 house, with equally modest insulation values, cost just over £200 a month to be properly cosy during the coldest months last winter. It looks a little shocking, £200 a month, with only a state pension. But during temps of 10-15 C it costs nearer £100, and almost nothing in summer. I don't turn my system off even then, as summers where I live are cooler and for longer than in the south, and a little top-up warmth, at negligible cost in the cool evenings is most welcome. A neighbour who still has night storage rads pays nearly the same every month to have a much cooler house, something they are beginning to appreciate more as they get older... So, sometimes more is less, if you see what I mean.
So how's such a system really going to work successfully in a 3 story, 6 bedroom solid stone victorian house with large single glazed sash windows in each room and x26 double radiators, currently powered by a 85kw oil fired boiler? Would have to be a pretty big heat pump to cope with the required heat output and therefore I suspect m unbelieveably expensive to have installed and then run.
Thank you Tom , very informative video. I got my heat pump in July this year and just use it for hot water currently as my house is a new build (B EPC). Your tips will be handy as I keep it going through winter now .. 😊
Thanks for commenting, hopefully all working efficiently when you finally need heating! (We have had ours on for a while now...!)
Useful summary. Still learning how to use our heat pump just over a month in. Can I ask what sort of temperatures you run the system at?
Hi Alan, we have thermostat set to heat our home to 20°C. We store water at 48°C.
One of the key points is the flow temperature from the heat pump and having that set up with weather compensation controls to vary with the external temperature, i.e. radiators warmer when the weather is cooler and vice versa. Depending on your system this could be done in a variety of ways but I hope was set up like that when it was installed.
Hope that make sense?
Tom
@@TomBray-LowCarbonLifestyle great. We already have the water at 48 (50 was a bit hot frankly) and are experimenting with the thermostat otherwise. I need to check the curve setting but we certainly have the weather compensation running from early experiences
It all sounds great ! Can I ask what is the size of your property in square metres to work our what size heat pump is required ?
We are about 110m2, and a 5 kW heat pump.
An installer should do a detailed heat loss assessment on your behalf rather than using comparison or rule of thumb (but for to have an idea!)
Tom
Just had mine installed. Its an Arotherm 5kw which looks to be the same as yours. Currently curve set to 0.4. System is designed to 45c flow at -2. and got a new Heat Geek cylinder. Interesting to see what my annual figures are. Its on OpenEnergy Monitor heatpump list.
And how much did all that cost?
What do you think of the HG DHW cylinder?
I'm thinking of buying one.
@@davidreece1642 Seems good so far. COP of over 3.5 heating hot water to 48c.
@@richardlphillips Hopefully COP of over 4 once you are familiar with your system.
@@davidreece1642 Hopefully, design is sound i think 🤞🏼
Interesting stuff! What model is your Vaillant? I note the aroTHERM Plus use R290 for the refrigerant, and as such seem to have stricter requirements for installation, notably with regards clearances to establish a protected zone. Further - I note building regulations state an ASHP must not to be installed within 1 metre of any property boundary. Is the wall to the right of the pump not a boundary wall, and what about the wall to the rear of the unit, is that a boundary wall with a neighbouring property? Thanks!
Hi Jason, yes ours is an Arotherm plus, 5 kW. Installation guidelines for this unit are here - professional.vaillant.co.uk/downloads/aproducts/renewables-1/arotherm-plus/arotherm-plus-vwl-35-75-a-s2-installation-operation-manual-0020330791-03-2806789.pdf
I suggest our system is installed as per 4.1.1.4
The wall to the rear of the heat pump is a boundary wall, I had not appreciated that property boundary rule and it does look like the system would not meet that rule. Which is not great from our installer...! I guess there is a risk that we need to get planning permission for it, or that a building control officer would tell us to remove it.
Although it is at the property boundary, it is 5m+ from the neighbouring property. This may mean it is acceptable...?
I am unsure why that rule exists and feel like it could be up for challenging. There is also MCS guidance about distance from openings which feels more reasonable in terms of noise risk.
You are definitely into the detail...!
Tom
@@TomBray-LowCarbonLifestyle Thanks! Yes - 4.1.1.4 ‘Ground installation in a building corner’ on page 8 requires an overall clearance at ground level of 2600mm wide, 500mm to the right of the unit, and 1000mm to the left of the unit. I’ve watched some of your videos, where you show the unit installed, and you sat or stood by the unit. I don’t see how the space available is 2600mm wide at the base, or 500mm from the right wall, or 1000mm from the left wall? And indeed, the 1000mm government requirement from any boundary under permitted development, which could also cover the wall to the right of the unit? It's not so much being into the detail, it was one of the first things that came to mind when looking at ASHPs, given the strict location requirements for R290 amongst others, which is a fundamental topic. Thanks again!
My advice on living with a heat pump is to be firm with it from day one, make sure it does its business in the garden and sleeps in its own bed.
Ha! Absolutely agree! No jumping up at strangers or sleeping on the sofa
Your heatpump was free you say so what's not to like then.
I work in a similar industry to the heatpump industry and I hear the name Daikin alrtherma mentioned has any body had any breakdowns compressors, electronic PCB yet they cost a fortune,and what I'm seeing the contractors want to replace the whole new system to get you a warranty again.
Now compare that to a forty year old cast iron boiler like I have and the only breakdown I've had is a gas valve £80 in the 26 years I've lived there. I pay £112 a month to octopus for gas and electricity for a big old five bed house 13 rads .
Any thoughts .
Unfortunately Heatpumps are relatively new tech to the trade and there is not enough expertise out there (like EVs) for detailed repairs especially on electronics issues. Your cast iron gas boiler has cost you way more over the years through inefficiency than a proper expert repair of your heat pump. Same lack of knowledge on modern condensing boilers and domestic appliances in general - new control board mate £££ is the answer you get!
@simoncroft9792 that's the one fan motors £400 X2
PCB for outside alrtherma £800 ,they have become part changers at who's expense.
I still think my cast boiler is cheaper.
Maybe I'm still waiting for the cheap electric power we have been promised, then I shall get a nice simple electric one .
@@captbarb6642
Sorry to disappoint you but there is never going to be any ‘cheap’ electricity, the Providers are not going to cut their profits and lose out. The government as usual are lying to us. Keep your boiler and wait until the heat pump industry has really matured and there are plenty of installers and engineers who know what they are doing!
There will never be ‘cheap’ electricity! The providers are not going to lose out on their profits and the government are lying to us as usual! Stick with the boiler for now until the industry and servicing support matures and then possibly change. But wait for now.
@@captbarb6642 Your logic is similar to "The Ford Ecoboost engine is a £2k replacement, so be wary of buying a petrol car." Many Heat Pumps come with 5-7 year warranties, beyond that check your home insurance, often up to £1000 is covered for fixing a heating system fault.
There was a study in Sweden in 2014 covering 2006-2010 into heat pump reliability by the insurance industry to see where the common faults were and where to improve them. They summarised it with this:
To summarise, the installers’ and service technicians’ general opinion about the annual number of failures presented in the failure statistics was;
• Heat pump owners are satisfied with their installations.
• Not many heat pumps break down in comparison with the number of installed heat pumps in Swedish households.
• The heat pumps that break down are mainly old ones, ones installed by the owner or “cheaper” heat pumps not designed for the Nordic climate.
• There have been problems with some models of air-to-air heat pumps, which were actually air conditioners designed for the Mediterranean climate that have been sold as heat pumps on the Swedish market. But the number of this type of heat pumps sold has decreased on the Swedish market.
• There have been problems with some models of air-to-water heat pumps with insufficient compressor capacity, not suited for the Nordic climate. Nowadays, air-to-water heat pumps are generally equipped with compressors that can deliver the pressure rise needed to heat domestic hot water during the winter.
• Failures usually occur on heat pumps in the age range of 5-7 years, and are generally caused by poor installation, improper operation, lack of maintenance or because
some of the components have shorter lifetimes than the bulk of the heat pump system itself.
• Production defects do occur, but for the heat pump brands that the interviewees install and service, the manufacturers take responsibility for their products and try to
solve the problems that arise. The installers and service technicians would not work with brands and manufacturer they do not trust.
Correct me if I’m wrong but with the average length of time
folk stay in a house before selling and moving is 8 years and the average usable life of a heat pump around 10 to 15 years, it would be realistic to think that every time you move you’re going to have to install a new heat pump?
I was thinking that selling a house with a heat pump would give you a premium but not so certain now :-)
Unsure on the time people spend in a house. A heat pump may well be 10-15 years, which is similar to a gas boiler....?
I think it may well give some premium, already been through the effort and expense to install and get working well.
Some might want to avoid a house with a heat pump I guess...?
Good video. We've also had a heat pump for 3 years and I've played with the settings a lot too. I've actually turned weather compensation off (controversial) and basically run the heating from 7am-9am and then 11-4pm at 34 degrees flow to 'charge' the house with warmth when the air is warmer outside. Heating SCOP for last 12 months was 3.8. I bump the flow temp up a few degs in colder months but find this actually is more comfortable because allows the house to cool slowly when going to bed. We also have Octopus Cosy so most of my heating is done at 40% discount. Smart tariffs have totally changed the game to running costs.
Do you run the heat pump through the night as well ? Or do you run it just when you are in the house. Did you have bigger radiators installed or did you go with the existing ones?
Hi Carl, sorry for the slow reply, yes, what I have settled on after a few years is to run through the night. And because my wife, or I, tend to work from home most days, we do leave it on all the time. When we go away, I turn the thermostat right down as 'frost protection'.
We had radiators upgraded, and 2 added, but the upgrades were to a similar size of the previous installation. I might have asked for bigger radiators in a couple of places if I knew what I know now!
Tom
I have the curve on 0.2, really well insulated house and I suspect my heat pump (AroTherm Plus 7kW) is a bit oversized because previously I had it set on 0.35 and it was cycling like crazy (20 minutes on, 20 off). I lowered it, went for aggressive setback temp and now when it runs it runs for 40-60 minutes and then stays off for two hours. Before I had COP 4.1-4.2, now I am hitting 4.5 (heating only, DHW is a different matter - 3.1-3.3)
Well that is really efficient, and much lower heat curve than me. Does sound like the heat pump is too big, which is a shame, but does sound like you are getting much better performance now.
Tom
@@TomBray-LowCarbonLifestyle yeah, it might not perform as well when real winter sets in :D I am in Czechia and my location’s coldest temperature (that is used to calculate heat loss) is minus 12C. But these years we rarely hit that kind of cold :)
Thank you for taking the time to share your experience, very interesting
Thanks for commenting!
Thanks for the video - what temperature do you heat your house at?
Hi Graham, we heat our most occupied space to about 20°C, the system can heat to higher but we are comfortable at that temperature. Bedrooms will be slightly lower than that.
Thanks
Tom
We are an elderly couple who have just moved to a ground floor flat that has air souce heat pump. We are trying to come to grips with this. We have been keeping it on 24/7 at 22 degrees but find this too warm at night. Would be gratfull for suggestions. Opening a window would seem counter intuitive. I have taken to lowering the temp before bed to 19 but from what you have said this is probably not the thing to do. I would welcome any advise you can give.
Move to a place with a gas boiler, the heat pump will drain your savings.
Ignore @dellawrence4323. It is possible to have a Set Back temperature that you can use for overnight. We have day temperatures of 21 degrees and Set Back of 19 degrees. If you're not sure of the controls maybe contact a local Heat Pump specialist who should walk you through the controls.
Our experience of our Heat Pump is that we are paying about 50% of what we would have been using gas.
Hi Jacqueline - sorry I missed your comment last week, I suspect you may be able to control using timings as the other comment said, so the system would be ‘on’ but not trying to get to 22 as you have during the day, we tend to call this ‘set back’
What kind of heat pump do you have?
Tom
Hello Tom - I would be interested to know if you think having a heat pump has reduced condensation in your house
My thought is a more even and constant temperature in your house would reduce cold spots and subsequent condensation ?
Hi Tom, my heat pump was installed in June, so I’m only starting to use it to heat the house now. When we talk about running 24/7 it can be confusing. The real question is how long is it actually doing something for and when it stops doing something how long does it stop for? I’m trying to understand the optimum setback. From my limited experience when it’s running I get around 0.5 c increase in temperature per hour ( does that sound about right). When it reaches temperature it stops. Now I’ve noticed that the first half hour of running is very energy intensive and then it settles to a less intensive level but still about 75% of the initial half hour, the energy consumption doesn’t drop below that. So to minimise that initial cost it seems to me to require using a much bigger set back temp. Ie the temp at which it carries on again. What do you do and what have you noticed about the energy consumption in that initial half hour compared to the rest of the session. About how many sessions ( or cycles) do you get in a typical day. Thank you for the video. My situation is similar to yours, ie no pv, no batteries. But I haven’t been brave enough to go the agile or cosy route.
Thanks for the video Tom. I have had my 10kW Vaillant Arotherm installed for 3 years as well - this is the first time I have come across this kind of explanation and has really helped me to understand the system a lot more! I have had a fiddle and found my COP over 3 years is about 3.05, and my compesation is set to 1.2. I find the radiators are forever turning on and off so will be playing with this soon to get the more constant running that you suggest!
I have solar and 10kWh of batteries so taking advantage of cosy octopus to charge those up 3 times a day and get that reduction in bills as well - once again really appreciate the detailed explanation and honesty - well worth a like and subscribe!
Thanks for being in touch Jon! Good to have you on board!
I suspect dropping your compensation curve a bit would improve your COP substantially, and give you less cycling. 1.2 is similar to what I had in our first year.
I can imagine with solar, a battery and cost, your bills are pretty low each year.
Great to hear from you, would be brill to hear what changes you make and what effect that could have!
Tom
If you has the space for it, get more radiators. You problem is that the radiators gets very hot, so the thermostat turns off, and fairly quickly it becomes colder again, so the thermostat turns on again.
With more radiators (a higher surface area who can emit heat), the radiators' surface temperature won't fluctuate as much as it's doing today. You can connect them in series, i.e. one thermostat controls e.g. 2 radiators, meaning that the same heating fluid (usually water) flows through the 1st one and thereafter the 2nd.
@
Question on set back temperatures that you might be able to help with. I am now setup on weather comp only - however finding that the system running at night is too warm for me.
Should I turn down the set back temp? Does that even affect the unit?
Or should I just further reduce the curve value?
I guess final option is some smart TRVs in bedrooms
@@jonnutt8999hi Jon - I think you have identified all the options and any of these could be right for you.
Turning the weather comp down would be the best for efficiency but may mean you lose out on heat during the day a little. TRV in the bedroom so it doesn’t get too warm could be good. But set back temp, or 1-2° may be all you need…
Worth trying each…?!
@@TomBray-LowCarbonLifestyle just reporting back on a bit of progress. WC turned down from 1.2 to 0.4 which for us holds a comfortable 20-21C in the house. This is substantially more comfortable than we were before - where the heating was doing 20C all day but going on and off leading to feeling cold.
CoP is excellent now - 4.3 so far in December which has been fairly cold. 4.2 for November overall. In combination with the batteries and cost tarriff my energy cost is down significantly - was £110 for November even with all that heating.
I want to say thanks again for the video - your explanation is what drove me to explore this change and I am happier than you can believe! The heat pump was always a source of anxiety for me as I worried about the running costs and so scrimped on the heating - no more! The system is great, thanks so much
Thanks for this informative video. Getting real world opinions and experiences is invaluable.
Thanks for commenting!
what isthe temperature in the house, and what is the hot water temperature
Hi David - we heat our home to 20/21°C. Hot water to 50°C with regular pasteurisation above 60°C
I’m just looking into to having one fitted i have a new build house with solar and battery storage. But slightly concerned in the extra cost of electricity as i have to gas broiler running pretty efficiently and we don’t use a great deal of gas and as much as i feel it could be good to have 1 I don’t want it costing me more money.
Hello - I think that is an interesting question, if the house does not need much heat, is it worthwhile installing a new system... from a CO2 perspective, I think the answer will be yes, even small amounts of gas that you burn would have associated CO2 emissions.
With solar and battery storage that would help keep costs to run a heat pump very low.
If you run your system efficiently already, at low radiator temperatures it could be a heat pump, without many changes internally, is an easy-ish job. If you have space for a hot water tank as well.
How much gas do you use each year?
Tom
@ so we tend to average 110-150kWh a month on our gas.
@@Bikebros27 that is very very low! Must be a very well insulated home? Average UK home will be around 12000 kWh per year, so could be 2-3000 kWh per month in Jan / Feb
We've just had a Mitsubishi Ecodan heat pump installed in our 1950s Home last week. Struggling to get to grips with how to control the temperature correctly, as it seems to go either really hot or completely cold instead of a nice steady heat. I'm a bit crap with understanding how these things work. You seem to know your stuff!
Hi Alexander - that’s frustrating! Are you able to get your installer back?
What id be suggesting is to get the heat pump onto weather compensation- this video may be helpful? ua-cam.com/video/-983aLzVZ_I/v-deo.htmlsi=IV-taBZ8lFys72xw
Tom
@TomBray-LowCarbonLifestyle Thank-you for your reply. I haven't had them back to be honest. I'm having a hard time figuring out the bedtvway to run the heat pump overnight. I'm essentially turning it off as im setting it at 16 degrees. Then in the morning it takes a while to get going again.
Thanks Tom, thanks Esther. You are one of the community of You Tubers who have inspired me to get a heat pump. It was fully installed a week ago. My rational brain tells me my radiators are not hot so I should not be warm but I feel really comfortable. I understand the science behind this but I have lived with gas central heating for so long it is difficult to change my mindset.
I opened a bottle of wine to celebrate the day that my gas was turned off. I am still getting to grips with the integration of my Mixergy tank, Eddi, Harvie, Libbi and ASHP. An engineer from Octopus is coming to see me tomorrow to help me.
At the moment I have the house too hot 🔥!
I haven't worked out the best timing and room temperatures.
I have been inspired by so many people on You Tube who have encouraged a 70 year old, widow to take the plunge. I was nervous and frightened of making a mistake but positive feedback from other people encouraged me to go ahead. Early days but I am sure I have made the right decision. I am now saving for an EV.
Thank you once again.
Hi Jean, thanks so much for your comment, really encouraging to read! Well done on taking the plunge!
It does sound like a complicated system, so I hope the Octopus engineer can help talk you through.
It is strange to not feel the very hot radiators but the house still getting warm, takes a little getting used to!
Do get in touch if I can help in any way!
All the best
Tom
FWIW I think you've made an excellent choice. Ignoring the costs or environmental issues, the comfort you feel from the small heat trickling through your radiators is much better than the boom and bust temperature changes you will have previously had. It was a huge leap of faith for us but I am really happy, and more importantly, my wife is really happy with the continuous temperature of the house and the hot water we have.
It might take a little while to get the settings just right to get the best efficiency and lowest cost, but once you've done that you can just about forget about it.
@@jeanh9641 well done you!
I'm 70 now but got an EV 3 years ago, solar panels 2.5 years ago and a heat pump from Octopus this year. They all work well together and we're glad not to be running a cpmbi gas boiler.
Don’t do it ! Stick with your gas boiler. You won’t save the planet or any money.
Great and very reasonably presented video on the pros and cons of heat pump ownership. We love ours and I'm very happy to say we beat your average unit cost by 2 pence (15.3p) on agile! Keep up the good work of spreading the word and debunking the daft anti-heatpump fake news!
Thanks so much for commenting and great work on the low agile rate!!
Valuable insights into a subject I'm only now looking into. Thank you very much for relaying your experiences.
Thanks for engaging with the video. All the best on your journey!
@@TomBray-LowCarbonLifestyle Thank you, sir. I wish you well.
Hello may I ask, did you retrofit the heat pump to existing water radiators that used to be powered by let's say a gas or oil furnace?
Hello - we retrofitted to the same pipework and a couple of radiators stayed the same, but several were switched
@@TomBray-LowCarbonLifestyle Also, are you using it for cooling as well?
I notice you never mentioned if there was a noise element from your pump. Is that something you or your neighbours are aware of.?
How loud are heat pumps? - Low Carbon Lifestyle Episode 38
ua-cam.com/video/ksrAZM-ldI8/v-deo.html
Not been a problem!
Hi Tom, great video that demonstrates that heat pumps do work in average uk houses. Couple of quick questions, firstly how many radiators did you have to change, what increase in size, and how many throughout do you now have. Also what flow temperature range do operate at and what is the average?
Hi Jonny, good questions... you may have seen I mentioned our system was installed as part of a research project, maybe to maximise their income the contractors doing the install replaced all the radiators with similar ones of similar sizes, we also added two radiators. So, we probably could have coped with just adding two radiators rather than replacing them all.
There is a reason to replace them all in terms of ensuring a clean system but not always required.
So no real increase in size from our old radiators.
We now have 8 rads and a small area of UFH.
I don't know the average flow temperature but we use the weather compensation curve of 0.6 - you can see the curve on this page energy-stats.uk/vaillant-arotherm-weather-curve-information/. So our system will be between 30-40°C most of the winter.
Hope that is helpful!
Tom
That's really interesting Tom because the general consensus is that you need that extra surface area to able to operate at those much reduced flow temperatures. How big and where is your ufh? I think the results you are getting are a good measure of the suitability of heat pumps for most UK homes! you should contact Dale Vince with your findings he currently has been dissing them as not the answer and has the ear of influential people and has an enormous following on social media. Thanks for your reply
Jonny
Also if it's not too much trouble could you send ne spec details of your rads. Thanks
Hi Jonny, sorry for the slow reply - extra surface area means better efficiency but many heat pumps can run at high enough temperatures to cope with fairly normal sized heat pumps, just means we lose out on efficiency.
Our UFH is in our extension which is about 20m2.
Dale Vince is way too far gone down his 'green' gas rabbit hole, lots of people have tried to explain heat pumps to him over the last few years.... I tend to like what he says but feel like he has a massive blind spot here.
I don't have a spec for our rads but they are fairly standard double panel (k2) rads.
Thanks
Tom
Thanks for the video. Very informative. I have one concern re locating the HP. The only viable location for me would be with the fan blowing cold air over a path. I’m concerned that in winter it might turn a normally wet stretch of path into a treacherous icy spot ready to catch out anyone approaching our house. I wonder if you have any experience of this?
Hi Tim,
Good question, and can share my experience of this. Our heat pump is outside our back door, air blowing across the path we use to walk out of the house every day. A couple of things that I have noticed happen when the weather is cold and wet, a) the flow of air keeps the paving dry in the area immediately in front of the fan, b) when it is very wet the cold air does not seem to cause a particularly icey patch, i.e. the air seems to mix quite quickly and the temperature on the floor does not seem to be different to elsewhere
Overall, in 3 years, I do not remember a time when there were any issues with ice in this location. Although, as with any management of icey conditions, I imagine we could use salt / grit to help....
Hope that is helpful?
Thanks
Tom
A person paying £5,500 after grants for a heat pump installation would also pay interest on the money borrowed of around £500 per year, so that wipes out any savings on heating as a new gas boiler can be installed for under £2000. Also UK electricity is generated using up to 60% gas generation especially in calm weather conditions when there is little to no wind.
Hi Alan, thanks for engaging with the video.... would love you to watch this video too on savings... ua-cam.com/video/hYcW65Oz3qI/v-deo.html
A heat pump is worth much more than just savings!
On average over the last 12 months, the UK got 28.1% of its electricity from gas. But even if we got 100% of our electricity from gas, a heat pump would still use less gas than a gas boiler...!
1 kWh of gas burnt in a gas power station, would deliver about 0.4 kWh of electricity to a home, a heat pump would then deliver 1.2 kWh of heat (at 300% efficiency, often much higher) to a home.
1 kWh of gas burnt in a gas boiler would deliver 0.9 kWh of heat to a home... so if we want to reduce our reliance on gas, we should move to heat pumps asap!
AND, fortunately, we get our electricity from a much broader range of sources...
You may find - www.mygridgb.co.uk/last-12-months/ helpful
Tom
I take it you don’t pay interest on a gas boiler then?
This is a great video, thank you. It also highlights a problem a lot of people are going to have. Which is that a lot, if not the majority, of people won't understand how to improve the efficiency of their heat pump or simply don't want to fiddle with the settings. Meaning their experience is unlikely to be a good one. The other issue is the dynamic pricing. Once everyone starts to charge their EVs and/or use their heat pumps during those currently cheap periods, those won't be cheap periods anymore.
Hello - I was a quite early adopter with our system, and the lessons I have learnt (and thousands of others have learnt with their installations) will mean that many systems will be commissioned / set up with efficiency in mind.
Yes it is a fair point about dynamic pricing, if we have smart tech / batteries and charge EV's off peak, that will flatten out the demand and mean prices don't vary as much. But it will also mean we are taking advantage of very cheap electricity when the wind blows and sun shines, so at that stage, electricity costs could be very low indeed. I did a video about that topic a while back too - ua-cam.com/video/eK1ehg5Fv6s/v-deo.html
All the best
Tom
Thanks, great videos. Shame about the comments that don't seem to get the return on investment, carbon savings and comfort/home improvement points. Got a Vaillant 7kwh myself, installed in September but early days. We are on Cosy having seen that Agile is not so beneficial in the last few low wind months. Both tariffs also aim to encourage load shifting away from the peak demand hours so I tried managing the system myself to bridge the high peak (4-7pm tariff) but an now trying Havenwise who do it remotely using an algorithm to learn your situation to optimise price per kWh heat output. So far price is down 20% on all our electricity (25p to 20p). Cop is 3.0 in recent winter-ish months so not clear if seeking bridging is lowering efficiency but price reduction is encouraging. I reckon we are shifting around 2kwh each day from high peak period (plus more from standard to low). If this was done eventually across say 5 million households then it would avoid the need for one or more gas fired power stations or help achieve the huge increase in clean electricity and transmission that we will need. Thanks again Martin
Been watching for a while now. you mention heat output monitor.. which one please
Hello - our heat meter is a sontex superstatic 449 heat meter
Tom
Like all new technologies it takes a bit of getting used to. Until fairly recently, no one talked about flow temperatures and most boiler installers didn't get it either. It will take time, but someone has to go first, so thanks Tom!
Thanks Edward, looking forward to visiting yours one day!
Great video and really interesting comments. We have a modern 4/5 bedroom house and have been quoted £27,000- to install a Heat Pump, (+ another £6,000- for solar panels), the biggest issue being modifying the plumbing and replacing every radiator in every room, so sadly, I don't think we'll be going there, living here in the far SW with poor infrastructure and dire lack of tradespeople. What interests me is the Zero Emissions issue though in respect, for instance, of unceasing and increasing leisure Air Travel; I understand just one of 13 daily BA flights to New York will, for instance, just in the Take Off phase, emit the same gases as my 95% efficient oil boiler will in 10 years, never mind the emissions in the Climb, Cruise, Descent and Landing phases. Just saying!
Octopus Cosy is a very good tariff if used with a small battery. You get 3 off peak periods (4am-7am, 1pm-4pm, 10pm-midnight). With a small (10kwh) battery you can run with almost no use of on-peak power.
Note, as off-peak power is generally much less CO2 intensive than the grid average (gas generation is a bigger proportion of generation at peak times than at off peak times) is also greener.
We've got Octopus Cosy with a heat pump and fairly simple 3.2kw battery setup. It's changed the maths dramatically for us
HI Alberto - absolutely! We don't have a battery yet, but cosy can work out very cheap too. I have preferred agile as seems to give more cheaper energy, but you are exactly right, moving away from the peak tends to be lower emissions too, the Octopus smart tariffs are great at incentivising that!
Tom
Did you have to upgrade your radiators?
Hi Yorky - you may have seen I mentioned our system was installed as part of a research project, maybe to maximise their income the contractors doing the install replaced all the radiators with similar ones of similar sizes, we also added two radiators. So, we probably could have coped with just adding two radiators rather than replacing them all.
There is a reason to replace them all in terms of ensuring a clean system but not always required.
So no real increase in size from our old radiators.
We now have 8 rads and a small area of UFH.
Thanks
Tom
is your energy provider using renewable sources?
Hello yes I am with Octopus which is a 100% renewable energy tariff. In emissions reporting it is good practice to use the average grid carbon intensity rather than assume 100% renewable, so in my calculations I have used the UK average.
The grid is getting cleaner and cleaner, and by 2035, if not 2030, there will be very low emissions for a kWh of electricity used for everyone
Thanks
Tom
@@TomBray-LowCarbonLifestyle noice
Thanks for the information. What is your target temperature at home? Also, don't forget that you are no longer paying a standing charge for gas (assuming that you have disconnected it!). I'm in a 1920's semi in Salisbury (my home town is Carlisle and my family are from Seaham Harbour so I am a bonafide Northern miser); I have about 4kWh of panels and 16kW of battery storage. I still have a combi boiler for heating and hot water but I also have a water tank which feeds into the combi boiler. When the price of electricity drops (I'm on Agile like you) I pre-heat the water in the tank so that the boiler doesn't fire up. Last year my combined electricity and gas was under £300 for the year (I export about £50-60 of electricity a month in the summer). I couldn't really justify the £9k that British Gas quoted for the same heat pump that you have which I really would like. However, Octopus produced a very reasonable quote for a Daiken HP. That said, I am always keen to support UK manufacturing when I can so I opted to wait for the larger Cosy HP to come out (Only 6kw at the moment and I need just under 8 seemingly). Once again, thanks for taking the time to post.
We aim to get to 20°C where we keep our controller, in the room we spend most time in.
We actually still have a gas hob so still have standing charge unfortunately, a discussion I have with my wife fairly regularly...!
Makes a lot of sense to heat up the tank using low cost agile rates, and well done for getting that far to have quotes for a heat pump and a plan for the future, way further than most people!
Good to hear from a Northerner in exile - welcome back at any point!
Tom
What about instant hot water to your tap, is that an issue?
Hot water comes from a cylinder full of the stuff.. can be set on a schedule and topped up automatically to any level you want.
Thank you for your interesting report. For our well insulated 2 bed bungalow we have solar panels ( no battery), an air duct heat pump and have retained our reasonably efficient gas boiler radiator central heating.
The heat pump functions as air conditioning on hot days in summer.
We have been reluctant to use it as our main heating in winter because of the difference in price per KwH between gas and electricity.
What we lack is an easy way of comparing actual cost in real time.
We have deliberately avoided having a smart meter installed but we do have a real time display of solar generation against grid usage.
I would value any pointers towards being able to see a real time price comparison of our gas use against electric use.
Many people report high COPs with air to air heat pumps. A COP over 3.6 and it'll be cheaper than gas.
ua-cam.com/video/tStlklv1jcE/v-deo.html
It'd be interesting to know your costs if you used it instead of gas heating for a month. But I'll not be paying the bill!
is the noise from the heat pump outside an issue for you or your neighbours?
I don’t think so - it is mostly unnoticeable. On the coldest days when the heat pump is loudest (not that loud) we and neighbours tend to have our windows and doors closed so not noticeable.
I did a video about this here …. How loud are heat pumps? - Low Carbon Lifestyle Episode 38
ua-cam.com/video/ksrAZM-ldI8/v-deo.html
So do you have different temperatures set in different rooms? What happens if you just want the bathrooms heated in the mornings? What happens if you just need heat in one room, say on a cool evening? Cheers.
Use the thermostat valves, or smart controlled ones on each rad.
Generally heat pumps work most efficiently with no zonal heating and at a consistent low temp. Unless you have insulation between rooms, heat spreads.
Hi all - you can control for each room with radiator valves, we don't really do that, just heat all our home, it isn't a massive house.
As Biggest-dh1vr says - it can be helpful not to zone a home at all
What are they like for noise?
I’ve done a video to try and answer that … How loud are heat pumps? - Low Carbon Lifestyle Episode 38
ua-cam.com/video/ksrAZM-ldI8/v-deo.html
We can’t hear the heat pump inside when it’s on. You can a little on a cold day when you’re stood next to it
Very quiet.. like a fridge freezer.
Brilliant video Tom! Really good to get some stats from a heat pump in action and I can't wait to get one installed after I (hopefully) buy a house next year.
Thanks Michael - hope you are well!
There is always questions if payback time, seems pointless to me as I'm sure it's increased your property value.
No-one every quotes a payback time for a gas boiler, double glazing etc, it'll be interesting to find out if there is any
Unfortunately the general public are NOT tuned in to this technology or have been brainwashed by the fossil fuel sponsored media. The Estate Agents in the Halifax area clearly say that spending £x amount on ASHP, PV or Battery will not add £x to the selling price of my house. I asked what % of £x it might add, and they said “small, if any” !
You're absolutely right - I would add in new sofa, new car, holiday etc etc. Sometimes these choices are lifestyle rather than purely financial
I would say I am ASHP curious. I have had 3.4Kwp of Solar since early 2012 ( on original very lucrative FIT). I also have a BEV and recently installed 10.5kw of solar batteries. On octopus intelligent go tariff so with batteries most of the electricity I buy is at 7p including charging the car. I generate about 3MW a year from the solar.
I have oil boiler so the FIT covers entire running costs of our house (oil+electric). Also have Tado smart heating controls on all radiators so the oil boiler really only burns when a room demands heat.
Our house is a 1820’s solid ironstone leaky cottage with double glazing…. Do I take the last leap of faith and pull out the oil boiler and gain back some of our garden when the oil tank goes….. really still sitting on the fence on this one. Great video btw.
Get a quote.. you may be pleasantly surprised.., hitched with solar, batteries and cheap rate it's very low cost I've also taken the gas pipe out on mine.
I always like watching your channel Tom as i live just up (or Down) the road in Hartlepool so it is obviously relevant to me. i have a heat pump being installed by Octopus at the end of this month which after the BUS grant has cost me £900 total. I was quoted by British Gas £7,500 after BUS so Octopus definitely was the best option. I will take your advice and run the heat pump as you suggest so many thanks to you and keep on with the updates. I have solar panels (some of which face north) and a battery and have been pleased with them. I also, like you do not think of pay back because in a way the whole thing has become a bit of a hobby.
Octopus will be installing a system designed to 50c flow which might perform at a SCOP or 3, but if designed to 35 or 40 could be 4.
A heat geek - and north east greenhome energy come highly recommended might charge you more upfront but you could earn that back with lower running costs over the years.
Worth considering
Radiator sizes are key
Thanks Geoff - would be great to hear how your install goes - try and get them to set it up with weather compensation and explain to you how you can alter the settings to push the efficiency up.
With panels and a battery I suspect it will be cheap to run whatever happens!
Thanks
Tom
We built a well insulated woodframe house 11 years ago, used heat pump to meet local green regs on newbuild (a knockdown of a damp 20's house). One electronic fail on heat pump, several issues with tank and especially the complex controls, sensors needed to juggle 35 deg underfloor, upstairs radiators with 60 deg hot water. Would recommend two heat pumps serving each call for heat and minimise the complex controls. May have to do this fairly soon as one of the control modules on pump is now no longer made by Mitsubishi, but expect will get better efficiency pumps. Huge dearth of heat pump engineers to serve existing systems, ours knows how to fix, check pump but needed 4 visits over 6 months to sort issues with periferrals, even though they said system was properly installed. Keep it simple, one pump per heat service, architect we know putting 3 pumps in for a big house in Wimbledon...third one is for AC! Our installer went bust within 3 years, have been told this is quite common, suggests warranty issues kill their margins, not sure how to combat this, especially for older home installations.
I've spoken to two ex-installers. They stopped due to the number of complaints. Whether this is due to the customers not knowing that it's MORE efficient to leave a heat pump running, at a lower temperature, rather than turning it on & off as per gas boiler, or whether it's because of systems failures/initial quirks I don't know. Either way, I couldn't find anyone locally to install, and Octopus won't install (yet) for flats. With winter approaching I've had to give up & go for a boiler to replace the 2 ancient gas fires /sad.
A £200 pa saving, for £13,000 outlay is a long RoI, so for most people it's probably still only worth doing if you are doing it for your bit for the environment, despite it benefiting people who work from home, or are retired or on parental leave or are carers, in terms of comfort. I will be getting two MHR mini-ventilators, to reduce heat loss and increase ventilation to reduce the damp issues in the two rooms with inaccessible window openings (bathroom & kitchen).
Getting 13k views in 4 days for a video about heat pumps is pretty impressive in of itself! Thanks for all the information you provide in these videos - hope to get a heat pump soon myself
Pretty crazy! Thanks for the encouraging comment, pleased I can be of some help!
Tom
So what is your constant internal temperature?
We aim for 20°C in our most occupied space, it is likely to be a bit lower in bedrooms
@@TomBray-LowCarbonLifestyle thanks Tom 👍🏻
Renovating/building our house at the moment going the heat pump/heat recovery ventilation combo along with solar panels etc., family of 5 and based in north of Ireland. Looking forward to having the setup and going with as much insulation etc. as possible in the house. These videos set my mind at ease a lot and happy to know it works.
Thanks for commenting Shane, sounds like a great renovation you are doing that will lead to a very low cost and comfortable home! Hope it all goes well
Tom
Very interesting video. What sort of temperature do you run your house at? My wife feels "cold" at 22°C We have an oil fired boiler so costs are B I G!
Hi Dave - we keep our most occupied space at about 20/21°C, but that’s our choice, it could be higher if we wanted! My wife is much more comfortable than she used to be because of the constant heat from a heat pump vs the peaks and troughs we had with a boiler.
Moving from oil to a heat pump could give good savings
Where are you based?
Tom
@@TomBray-LowCarbonLifestyle Thanks for the reply. We are based in South Oxfordshire near Wallingford. 1960's bungalow with 15cm insulation in the loft, double glazed throughout and cavity wall insulation installed about 25 years ago.
I'm at 0.5 currently but over night temps have been around 10 degrees c with a low last month of 4 and all good. leave mine on at 20'C room temps and like you I'm using less energy to maintain that. As an experiment I turned the room temps down to 15 degrees for the 10 hours I'm out of the house and my usage went up by 5KW vs leaving it on!! I use 10kw normally so seeing it ramp up 30-50% was a shocker. Like you say they come tuned like a boiler, I think my default install setting was weather correction factor of 1.2!!!! I have the 3.5kw arotherm plus which I had zero faith in coming from an 18kw oil boiler and that wasn't enough on the coldest winter nights in some rooms. I'm running 12 radiators if you include a small one in the airing cupboard and it manages just great. I do have solar panels and 20kw of battery capacity so run Eon drive which gives 7 hours of 9p kw to run the pump at night and charge the battery's. I didn't have this rate on the first year and my electric bills were hitting £200 a month at 34p KW/HR as I didn't charge the battery's over night and solar is maybe 50kw for all of December. This year I think my export earnings will cover November to February costs total! One think I might try this winter if it's cold is using the built in 3kw immersion element to assist hot water I run from 2:30 to 5am if required as a defrost cycle would kill heat output for 30 mins from the radiators. at minus 10 outside you could tell! I've not actually used it once in the 18 months the system has been installed.
Hi Tom, I’m in a very similar situation to yourself I.e. end terraced bungalow, with some new extensions on external walls to current building regs. We’ve had at a Midea heat pump for 2 years now and use the Octopus Agile tariff. The only difference would be that we have underfloor heating for about 3/4 of the house with 3 oversized radiators making up the difference. We also have a wood burner in our main open plan room, kitchen, dining and living room which we love to use in the evenings and heats the whole house when it’s on with half free and half paid for logs. I have tried running the ASHP on all the time based on room stat. But I am finding it 20-40% cheaper to heat the underfloor heating during the second half of the night, when it’s cheaper electric, as warm as I can get it and then switch off at 6am and the house seems to stay warm until at least 4pm with outside temps down to say -3’C. I think this is because the underfloor heating behaves more like a large slow release storage heater. Obviously the heat pump would be switched off to avoid the peak electric costs between 4 and 7pm. So the wood burner is usually lit during this period. I have tried a boost period between 1 and 4pm for the ASHP which probably saves is a couple of hours of wood or even avoid the use of the wood burner in the evening and the daily cleaning and reset ritual which does get tiresome towards the end of the winter. Whenever I’ve tried to run the ASHP on all the time except the 4-7 period I would say it produces heat probably 5-6 times in a 24 hour period and is on for about 1 hour with stat set with a 0.5’C top to bottom heating range. I have 2 on/off programmable periods on my room stat controller. I am trying to take advantage of the, usually, cheaper periods of electric of the Agile tariff, and avoid the expensive periods, which kind of goes against the leave it switched on all the time theory. Do you try and navigate the Agile cost ups and downs or do you just accept the lower average costs?
Tom just runs it low and slow all the time with no battery. I have been trying to dodge the peaks a little (I've only had a heat pump a short time), it helps having a small battery for the 4-7pm period.
Hi Tom, thanks for posting about living in a normal Victorian house. I thought I needed external wall insulation to use a heat pump. Could you post about the location of the heat pump and any noise issues. I have a small garden which is typical of Victoria houses in London.
Hello pmwut - sorry I missed your comment a couple of weeks ago. Additional insulation can definitely help reduce the size of the heat pump and reduce ongoing costs, but not essential.
Our heat pump is just outside our back door, noise is not an issue - I did a video about it here - ua-cam.com/video/ksrAZM-ldI8/v-deo.html
Terrace houses can be a challenge due to the proximity to neighbours, but a good installer should be able to talk you through all this
Thanks
Tom
Spead the word! We had a recent Open Green Homes event in bristol. It really good to be able to show what's involved. Give sensible warnings But also reassurance. It's a great way to heat a victorian terrace.
Is a Green Homes Event a Bristol thing? Interested in hearing more
@@TomBray-LowCarbonLifestyle Open Green Homes was run by the Bristol Energy Network. I think it started as a national thing. But they carried it on locally. There is 'visit a heat pump' run by Nesta which is national. There used to be a scheme called super homes too but not sure if it still runs.
I live in Bristol and have assisted on an open doors event, they are really good. Unfortunately I didn’t get any notices about this one so missed it.
Hi Tom, thinking of a heat pump, i get scop but to achieve a high scop you need to run the heat pump all the time which I understand but me and my wife work long hours so i only heat house 4-5 hours a day on gas so will i need more energy if running all the time then using combi. As for solar i have a great 7kwh system battery on a perfectly south roof. Great till october now when you'd need it run the heat pump I don't get enough power the toaster, well exaggeration but most cloudy days I'm not getting enough run the house as is. Wouldn't change the panels they are great best investment i made with the battery but the point at which i generate extra energy consistently to power the heat pump will probably be the point i turn the heating off. Just one to think on when doing the maths, you can't offset total energy generated from energy used by heat pump.
Hi David, yes this is potentially an issue for a few people, and although imperfect, I think a heat pump can still be suitable.
Although there is a saving in switching off heating when you are out, the overall energy required to get to a comfortable temperature is similar to if you kept the house at a constant temperature (it will depend on the house and external temperature etc).
So running a heat pump 24-7, or at a set back temperature 1-2 degrees below what you want it when you are back from work, would deliver slightly more heat than your gas boiler, but use a lot less energy. And if that means maximising the efficiency of the heat pump, that will be a low cost way to heat a home.
We used to heat our house like you describe, only running a gas boiler for a few hours a day, but we still used 12,000+ kWh of gas. Moving to 24-7 heating with an efficient heat pump, means we are using less than 4000 kWh of electricity.
It is a change of culture / thinking rather than particularly wasteful way to heat.
I need to do a video about this, as I am not sure I articulate myself well in comments!! And it is counter-intuitive / nuanced...
And yes, solar and heat pumps are imperfect, but October / March / April does get some generation that helps support a heat pump, and the summer months, hot water can be more or less free. Overall, your costs would be meaningfully lower coupling the three technologies, and even lower if adding in a smart tariff.
Thanks for sharing your thoughts!!
Tom
Thanks for this Ive looked and looked at heat pumps. In highland scotland 1800 on lpg it was exactly what i wanted however discovered concrete floors and did nt have budget to take them out got company in to quote they couldnt answer my questions and totally ignored my concerns over where pipes would be...they wanted to surface mount everything .. .Ive got 2 woodburners and my sudden health issues making me rethink AGAIN lol...is there a video about ur installation so i can see what issues you had ...thanks
Hi Fiona - that sounds like you’ve had a frustrating time. Hopefully you’ll be able to navigate it this time around.
Not sure if this video (the first one I did after our installation) would be helpful…? ua-cam.com/video/ZXNWuAK87SE/v-deo.htmlsi=YjxNA14d_V6c42U1
Do come back with any questions
Thanks
Tom
Hi Tom does your system still have hydraulic separation (buffer tank extra circulation pump) I seem to remember seeing one in a previous video. Have you investigated going open zone re plumbing the buffer tank into a volumiser on the return and running purely off the circulation inside the outside unit? It should improve the efficiency of the system unless there’s some specific need for the hydraulic separation such as micro bore pipe work
Hi Ed - yes we still have the buffer in place, and we haven't looked into removing it yet - I am conscious that others have done this with videos on youtube, not been a priority for me yet! But something we could do in the future. Would be great to free up that space the buffer takes up at the moment.
I have a service coming up from a Vaillant engineer, could be something we chat through then
Tom
6:04 The curve is very interesting as 0.4 means quite cool radiators a lot of the time, e.g. 10C in the day and 5C at night the flow goes between about 30C and 35C. Something must be on/off cycling, as wind and sunshine, people and appliances, affect the heating demand very much, at the same temperature. Haven't heard of variable flow CH circuit circulating pumps.
Hi Plinble - not sure what you mean here, the weather compensation curve means that flow temperature within the heating circuit varies with external temperature, and yes it can be as low as 30°C when there is not a significant heat load. This is not a variable flow central heating system, but a variable temperature system.
Tom
@@TomBray-LowCarbonLifestyle the main meaning is that external temperature by itself is too simple, there are other factors. Also on the pump side regarding the wind and relative humidity, e.g. making condensation should be getting you free energy.
@@plinble Hello - weather compensation control is a common way of controlling heating systems. Yes there are variables that impact on this, but it tends to work well for us.
You could also have room compensation, i.e. flow temperature changes with room temperature, this is analogous to external temperature but would include other factors such as cooking occupancy etc.
Hi, Solar doesn’t help run a heat pump directly as the main generation is in summer. However, if you use the octopus export rate of 8p or 15p then you can use summer credits to pay for the winter heating. I have solar/battery and ripple shares alongside an EV and export as much as possible at 15p. This means I am approaching zero electric bill.. not there yet but I am down around £30 per month and still falling as these strategies unfold. I was paying £150 electric and £100 diesel so the electric switch can be much cheaper.
Hi Pmac - absolutely, the best time for a solar + heat pump system is now, still longish days but into the heating season. In the depths of winter solar doesn't support much.
Sounds like you are making some good steps with your system, we have some Ripple shares, but no solar, battery or EV yet, one day!
Great video Tom (and Esther..). We've just signed up to have ours installed by Octopus and just waiting for a date now. It's been reassuring watching and reading all the positive feedback about ASHP systems, especially from people that have used them for several years now.
With solar and batteries and the Octopus Intelligent tariff we're hoping for some decent savings, as well as helping reduce emissions.
Keep up the good work..!
Fantastic, hope the installation goes well, well done for getting this far!! And yes, with solar, batteries and a smart tariff, I suspect your costs over the whole year could be very low!
All the best
Tom
What temperature do you call comfortable?
We heat to 20°C in our main living space, it is probably a bit lower than that in bedrooms.
@@TomBray-LowCarbonLifestyle Hi Tom - That seems to be the temperature that most people run their systems at. As I am in my latter years I find I need a minimum of 22 to feel comfortable. I guess that would increase the energy cost quite a bit.
@@paulcolu It depends on how you heat your home. If yours is the traditional way of having a thermostat that turns the boiler on and off then it will typically be set higher than the comfortable temperature. Stable State heating (which is common with heat pumps, but also doable with some gas boilers, but rarely implemented in the UK), will continually put in the same amount of heat as is being lost.
Those that have switched from thermostat-controlled to stable state heating have found using the same temperature as before was too hot, and have had to turn it down a few degrees.
@@BenIsInSweden Yes I am old school. Thanks for the comments. Very interesting.
I have solar + battery and am moving on to a heat pump this year 🤞What I've found is that we're not really using much solar generation over the heating season, because it's heavily stacked towards the summer months - around 10x more generation on a summer's day compared to winter. You're really relying on a good feed in tariff (15p/kwh from octopus) to make an effect on your bill. That said, you're likely to see massive benefits from the battery by charging up during cheap times on Agile or another time of use tariff.
Yeah absolutely, solar + a heat pump would be an imperfect pair, but whatever generation you can get can help supplement heat pump costs. This time of the year when we still have some daylight but also are heating is great, but peak heat and low of generation in december and january is frustrating.
Hope your heat pump journey goes well!!
Tom
We had our heat pump installation in June. Straight away we got hot water powered by electricity from our solar panels rather than burning gas. So that was an instant saving. Now in autumn a proportion of our heat pump running comes from the solar panels... admittedly not a big proportion. Exports will help but with an ev we don't export so much - just over £100 worth. But we aren't buying petrol or gas and have no standing charge for gas. I'd say solar, hp and ev work well together. @@TomBray-LowCarbonLifestyle
Great video. I too have been on journey over 4 years... now runnng on weather compensation... in an old listed building with modern extension. Works great.
We have solar and batteries. Use Agile import and fixed export 15p.
Its complicated to do the maths on solar & batteries! Remember most production will be in summer so more likely to export higher proportion.
Using tech to fill batteries at cheapest slots and minimise peak Agile.
I only moved from Tracker to Agile in last year. Import cost averaging under 11p. I'm optimistic even with winter usage we'll average under 15p.
With increased offset of exports as im importing more cheaply at night.
Hello Tom. My disabled daughter and her family moved into a housing association property where a new heat pump was installed(there was an existing pump that was defunct as they moved in) They were given no instructions, about how the system worked, or how to control settings for efficiency,,they have solar panels no idea if they have a battery, and I've been trying to obtain for them basic understanding on how it all works, your video has really helped, any ideas where I can gain education for them, noone from their housing will come out, they just say in the winter leave the system on constant, - any basic advice would be really appreciated. Thanks again
Hi Angela - where are you based?
If the home is warm and hot water is ok it may be worth just leaving it as it is. There may be some optimising to do on efficiency - what manufacturer of heat pump is it? There may be some good guides online / on UA-cam that could help with the specific system
I would be happy to try and help via the phone but can’t guarantee I’ll be able to!!
@@TomBray-LowCarbonLifestyle hi tom, we,re in ipswich.suffolk. we are clueless, haven't been given info.just moved them into this property, no hot water when they got there ,then informed s new heat pump system was measured up for and installed, we dont even know if this time of year the heating part has to be put on and left day and night, let alone how to adjust it. For optimal efficiency and cost I think I will have to pay for a technician to come and give us education and confidence to ,' try it all and see' as the housing association are not providing tenant guidance, thankyou for your kind offer, until I get a technician would you suggest putting the heating button on and leaving for a week and see what we experience. My daughter has no income, disabled and on benefits and being uneducated about cost and operation is of course of greater concern. Your video was very useful thanks
Hi Angela - do you know what brand of heat pump it is?
Leaving the system ‘on’ to heat to the desired temperature on the thermostat could be fine, although this could be expensive if not set up with weather compensation.
Until you get a technician out, I suggest using the system as you would any heating system, ie on when you want heat and off when not
Sorry I am not nearby otherwise I’d be happy to visit!!!
Tom
@@TomBray-LowCarbonLifestyle thanks for trying tom, just insane this sanctuary housing not educating us, and not willing to send their 1 regional heat pump tec hnician out who fitted it or provide paperwork. It's a brand new Mitsubishi pump,and I will find an independent technician. Many thanks again
This could be a helpful video ua-cam.com/video/-983aLzVZ_I/v-deo.htmlsi=XC1R7Uf6pxvVGxDX
Great video Tom, thanks. You’ve just made my mind up to invest🎉
Thank you for commenting! That is a great encouragement. All the best
Tom
Few people do this math. Thank you for doing so.
So it is well insulated, it's a terrace, also did you say it was a brand new heating system, all piping etc? Thats not average is it?
A Victorian terrace, with double glazing and loft insulation and suspended floors, not sure it’s that well insulated.
Piping was new when the boiler was put in before we moved in.
What would you call average?
An in depth analysis, especially to do with the pricing of the supply. It’s probably early yet, but there must be an element of maintenance for the equipment?
My place does not use water central heating, but I’m used to both solar thermal and PV in tandem, being half way through the old feed-in tariff. No local electricity storage, just exporting the surplus. Depending on you use of warm water, it might be worth considering the use of thermal tubes on the roof, as long as there is enough space for a 300l or so storage tank, if it’s compatible with a heat pump alongside.
Hi John - we had maintenance included as part of the installation for the first two years. And have just booked in service for the 3rd year for just over £200. Hoping to do a video as to everything involved!
I think one day we will install solar PV that will help power the home, heat pump and future EV, I think adding solar thermal would add too much complexity to the heating system, but could be good for some.
How do you heat without central heating?
@@TomBray-LowCarbonLifestyle My place is on the E7 tariff, and there is a mixture of storage heaters, simple electric heaters timed to night rate, a balance flu gas fire, and night rate water storage heating (to top up the solar thermal when required). It’s a small house, built with a heavy concrete block structure (which is an automatic storage heater, and keeps cool in hot days).
Ah interesting. Thanks for coming back to me
Just started to look at heat pumps and just have 2 questions. Once your on the heat pumps did you you have your gas supply switched off and if so do you still have to pay for gas as a standing charge. Secondly once everyone is on heat, how will the government claw back the lost revenue, increase the price of the electricity supply 🤔
Hi Darren,
We have actually kept our gas supply as we still have a gas hob, so paying the ~£180 per year for a very small supply! If we switched to electric / induction, we could remove the gas meter and save on the standing charge.
What lost revenue are you referring to?
Currently gas bills are subsidised when compared to electricity bills, for gas about 6% of the costs are taxes or levies, whereas electricity, around 30% of the costs are. So there could be a change in revenue for government as we would use a lot less energy, but the energy we do use has a higher income for the exchequer.
The bigger change will be electrification of cars, because fuel duty is a massive money raiser for government.
Final point to add, one of the reasons fuel / energy is taxed, is because they are damaging to people and the environment. If we burn less gas, and less fuel, our air will be cleaner, we will have less issues linked to lung disease and a lower NHS bill (for example)....
Thanks for engaging with the video
Tom
Great Work!
Thank you!
Solar panels primarily produce during summer and you primarily need heat during winter. I’m from Denmark, so I guess heating need and solar hours per month are pretty similar. Last year we had ~40 hours of sun in December (according to various weather reports)
Wind is generally a better source for ‘heating electricity’ and I guess you can get most of that benefit from your flexible tariffs by increasing/decreasing the setpoint for the heat pump output water… I don’t know if your heat pump supports that kind of logic, but it’s not impossible nowadays
Hello - completely agree, and I don't think I say the contrary of that in the video, I say that solar panels can help supplement costs, particularly in the Autumn and Spring, but definitely don't power the heat pump on their own.
Tom
@@TomBray-LowCarbonLifestyle cool, and a great video btw! You know a lot and are a good communicator with lots of enthusiasm!
Yeah there are tariffs for cheaper elec during windy days eg octopus intelligent and my experience so far this year is that there are more windy days (and nights) due to climate change in northern Europe. This not only makes heating cheaper but the whole house, plus charging an ev and batteries, thus extending the cheap time period. Solar is a bonus for 8 months of the year..
Great video, thanks very much. 🇬🇧
Thanks John
I got 4.7kWp solar with a 3.6kW inverter installed two years ago and I'm generating around 4000 kWh per year. The warmer months tend to be best for generation, so how it would work for a heat pump really is to get a good tariff that pays well for solar (Octopus Flux is a possibility - that's what I'm on and is intended for solar/battery owners; I do have a bidirectional car charger as well which is quite rare in the UK but it does the job) which would offset your winter bills. There is some generation during the winter but it's not a huge amount, though it probably tends to happen on colder days when you need more of the energy for heating so it may work out well.
I'm seriously considering a heat pump upgrade now. My boiler is 10 years old and whilst a lot of people would say that it's likely to be coming to the end of its useful life, I don't accept the 10-15 year life that is commonly mooted for boilers; my previous house had a boiler installed in 1999 and it's still working fine, although it's not been anywhere near as reliable as my current boiler. Also I found out about opentherm and started using that around two years ago to allow the boiler to modulate and run more often in condensing mode. I have a 1952-build terraced three-bedroom property and a nest thermostat to control it, set to 18.5C during the day, and I have averaged 6455 kWh of gas per year over the last two years to heat my home and provide hot water. I've learnt a lot from youtubers like you over the past week or so as I now have a quote from Octopus for a heat pump of around £3300 after the £7500 grant, though I do need some extras like a solid base for the heat pump to go on, and the survey hasn't been done yet.
It seems like a major part of getting efficiency from heat pumps is running them nearly all the time. If I may, do you vary your set temperature at all to take advantage of lower-cost energy periods? I see Octopus do a Cosy tariff that provides eight hours of low-cost energy at three different time of the day and I'm trying to gauge whether it's worthwhile to heat more during those times (perhaps by raising the set point by one degree or so) and have it back off during other times; the overall efficiency would obviously be a bit lower, but it might be cheaper to run as a result. (Whilst as I said I have a battery system through my EV and could charge my battery during those times and probably would, but I think the round-trip efficiency is only about 78% for using that to power the house, and that was installed as part of a trial and cannot be replaced with a like-for-like system if it goes wrong.)
Tom uses the Agile tariff, rather than Cosy, as do I. Some flexing around peak costs is possible on Agile.
Solar is great to defray the winter costs of the heat pump, generating credit in the summer on the 15p fixed outgoing tariff before the expensive heating of the winter.
@@Biggest-dh1vr That's a thought; I used to be on Agile. It might be worth me switching back to Agile, but I have to do the sums.
Hey, how did you get the bidirectional charger? I'm desperate to get V2H going as we have 2 x EVs....
@@justinjoanknecht3475 I was lucky. About 3-4 years ago I applied for and was accepted to a trial that involved my normal charger being replaced by the one I have now (a quasar wallbox) and I paid £250 to keep it at the end of the trial.
The longer the heat pump in direct sunlight the more energy efficient the system will be even in freezing sunny conditions. Easy installation isn’t always the best position for efficiency. You may face extra charges if the location make installation longer but higher efficiency long term will pay for itself.
There isn't a huge difference, Heat Geek did a test with using mirrors to direct more sunlight onto the coils, and it gave about a 5% improvement in the summer. Given nobody is going to have mirrors around their heat pump, and the sun is lower in the sky in winter, along with not being able to have the rear of the heat pump facing the sun all the time, the difference will be very negligible.
It's the air temp which affects the efficiency not the direct sunlight.
Heat curve is relative. It depends on the target indoor temp. In my case, it is 0,2 for 23,5C indoor temp.
Is that not when you have it on adaptive controls? If it is pure weather compensation the heat curve would be doing the same thing house to house...?
I may be misunderstanding!