One thing i have learnt in my 60 years is that if you do not know more than the "professionals" you while get screwed. For this reason a canal like yours is extremely important , especially when the average bloke is changing to a completely new technology. There while always be those who claim that the new tec is garbage , but most of that is down to incompetence ;-)

Awesome! The data sheet of the heat pump I have, which is probably few years old tech, doesn't even have a condition listed that achieves 5.9 COP. Looks like the most efficient heat pump models are R-290 units in the 5kW size or so. Can't get those in the US but at least have a relatively modern unit that should be much cheaper to run than an oil boiler. I'm jealous of that performance, nice job!

Thanks for a great video, I have experienced the benefits of really getting on top of insulation myself. We used a combination of products taking up only 95mm thickness, the difference when installed meant the bedroom warmed up by 2 degrees overnight first night we used end of September. I think your approach to understanding a subject like me, is that you can’t have too much relevant information .

In a 1950s house, just moved, we will be in touch soon but this is great news. Roof being done real soon!

I have a 10 year old house, insulated walls and windows, took out a condenser boiler, average gas bill for 3 months before Heat source fitted 450 , after the electric bill went from a few hundred to thousands yes thousands as I live on the coast and the constant chilled wind just stopped the dam thing working, just had a new gas boiler put in , what I did notice was the oversized rads I had to have fitted now heated the room so quick the gas boiler was hardly on, gas boilers and oversized rads are the way forward

Can you do similar monitoring for Dec, Jan & Feb please. Edit, I see that you will be doing follow ups during winter.👍👍

Very interesting, I have a Georgian townhouse that I’m renovating and may be ASHP is an option after all.. discounted before as it’s always suggested you need double glazing etc

Love the 'Golden Eye' on the N64. The only reason I still have my N64. :D Great video as well.. ;)

Cool (or rather warm). Those are the type of radiators we have with our heat pump system. To touch they do not feel that warm (which for those "not in the know") seems odd. But, place hand above top of radiator and you can clearly feel the convection hear rising. Mark.

Great simple video, love it.

Could you do a video on the Mixergy tank please? Thinking of installing one (along with an ASHP, Solar PV & Eddi) and would be great to know what you think of them.

Thanks for another great video. It was interesting to hear in an earlier video that when looking at SCOP it is biased towards the winter as that is when the heat pump is more used. Still when I look at specs for air to water heat pumps which give a specific SCOP for a specific flow temperature and out door temperature (e.g. Vaillant state their 12kw model at -5C outdoor can achieve an output of 10.8kw with a 55C flow temperature and a SCOP of 3.63). I guess I struggle to see how that applies to real life. 1: What are the assumptions made when a manufacturer states performance like that 2: How does that apply to a real life situation - Can you infer that if a system has been properly installed and never has to generate a flow temperature more than 55C then the SCOP will never be lower than 3.63? 3: Do these sort of quotes for SCOP assume weather compensation? Thank you for all your videos

Super interesting stuff, what was the heat loss calc for the building?

Sorry if I missed it in the video but is this the 7kw model? Also how many square meters is the property? If understanding the video and looking at the stats you had 3-3.5 last winter and the bigger rads has bumped the cop up to 5-6? Looks good, I have a similar age property if you want to do more experiments on my house then happy to participate :-) Appreciate all homes are different, but imagine this wasn't your office, how much would this have cost after the 5k government offer? Thanks.

Interesting to see this as it challenges the 'Fabric First' principle. Perhaps not for removing draughts, but for elemental upgrades not being the 'be all and end all'.

I wonder what will happen after you get the insulation fixed. Is there any risk of the Vaillant being oversized and not able to throttle down enough? I am guessing it will need enough radiator and underfloor heat surface and volume, but what does a big unit do if heat loss is very very low? (lets say just 1kW at -7 degrees)

Love this. Look forward to seeing how this all goes. Are we not better off insulating properly first though?

Do you have stats on how much potential output the old radiators had, vs the new ones?

I have 300mm loft insulation and 60mm cavity wall insulation that’s carbon bonded bead. My house is a 1950’s 4 bed semi. All new double glazing throughout now as well. Now it’s time to get an up to date EPC done. Anyone now where the best place to get an EPC done would be? I’m told they cost around £40-£50.

I'm running a 7kW Arotherm plus on a modern house with underfloor heating. My ASHP has a fence 1 metre in front of the fan. My combined (DHW + heating) SCOP since installation 15 months ago is 4.4 which is good. However, I have recently started measuring the air temperature going into the intake as I suspected its recycling chilled air, and sure enough I'm seeing temperature drops of 2⁰C+ when it's running. I can't move the fence, and I don't know whether moving the ASHP to give greater space in front of the pump would be worth the cost. Would you consider running an experiment with your ASHP to demonstrate the recycling of chilled air when a barrier is placed in front of the pump? You could show the significance of keeping the area in front of the pump clear with a movable fence panel or similar barrier. I'm irritated with Vaillant as the ASHP has been fitted according to the space requirements in their documentation (as I understand it), but it's clearly being affected by the fence. Thanks for reading!

Great Graph at 2m40 ... What is happening between the heat pump runs? is the circulation pump still going . or is it just resting? Does it just restart once the flow water has cooled , or are you timing the heat pump to come on every 50 mins or so, according to the heat need cacluated from weather outside?

How many rooms/radiators are you running of this heatpump? Have you got buffer cylinder?

Hi how much does the solar thermal collector tubes contribute to the scop and are the new rads double or even treble fin rads as I see you have a flow temperature of just below 30

I’m looking for my new build . Now is the question should I take a heat pump or a hybrid heat pump . And why . Is the set up both good ? Is the one cheaper ?

Thank you for doing this. Very interesting experiment. Looking at your live feed why does the heating cycle rapidly on some days like Dec 11 compared to others like Nov 29th?

Do you run a buffer? If you do is it in parallel or serie? Thanks

Can you tell me if you use a buffer tank alongside the 28mm or 22mm hidden pipework and is it just the trvs that control the heat out of each radiator relevant to the heating curve or does the room thermostat control the maximum heat or is it best practice just to rely on trvs. Thank you

Have you done a video showing how to set up the compensation curve for an Ecodan please - various plumbers I have had in the house have said not to use it - I am not very technical, but I need to get my heating costs down.

For listed solid walled single glazed Victorian buildings with only loft insulation would it be possible utilise an air source heat pump?

Have you done any videos on solutions like thermal storage (Tepeo, Sunamp, Caldera etc) for those that cannot fit heat pumps ?

High thanks for the videos but could you help me to explain the usage relating to electricity usage,on the live feed for say the 29th November it shows that you used (I think) 12.746 kilowatts that day is this correct or was it in one hour of usage sorry I am a bit confused regarding kilowatt hours and has the solar thermal contributed a lot to the reduction in running costs of an ashp and I also wonder if it would ever be able to put enough insulation in a 70s bungalow so as to make it into a passive home where no heating is required

Have you done a video on biomass boiler or even pellet stoves for heating

My Arotherm 11kwh current flow rate is 1000 litres per hour, I was advised to get it increased to 1700 litres per hour, what are your thoughts?

Nice cop ! Is this possible with any new heat pump ? looked to get one for last 3 years but couldn’t make figures work looking at it again due now with high energy prices but electricity is a lot more as well as gas so it still the same difference 7.5 p off peak for 6 hours and 40 p peak for the rest of the day and 11 p kWh for gas . We have 6.2 kw solar west facing with 5 kW invter and 13 kWh battery storage. Got a company coming Thursday to quote us what questions do I ask them to find out if there going to quote for a good system or just a cheap system like 2 others have . And how much energy does a home style heat pump use to run in the day in the winter ie on peak use at once ? I’ve been quoted for a 8 size heatpump before I think We live in a 3 bedroom fully detached bungalow and mid winter use about 60-70 kWh of gas a day and trying to work out if it going to be cheaper to use a tapo zeb on off peak electricity and use our 5 year old hot water cylinder heated from off peak and solar or get a air to air whole home setup or a heat pump any help anyone can provide would be great help Thanks Also these open energy monitors are they good idea for home use for a data geek or was this just for demonstration purposes?

What does the 0.6 for the weather compensation mean please? I'm aware of how to set the compensation curve, but I don't understand what a single number represent.

Hi Heat Geek, I have a question... I've set my condensing boiler to 40C and increased the size of the rads in some rooms to compensate. The house now maintains 20c fine. Is this a good empirical method of assessing heat pump suitability?

Goldeneye in the office (Y) We are electric only, On economy-7 tariff. Two high-heat retention storage heaters, one in the living room and one on the upstairs landing. Hot-water tank is immersion heated. Loft insulation done . Is a heat pump installation going to be incredibly expensive to replace this heating system as new pipework and radiators will need to be run? Also illegible for the grant I'm assuming.

I think the main question is, what did you use to get that N64 working on the big screen?

I really enjoy your informative videos. Sooooo regarding this video, please help me understand the physics of how the HP COP relates to any given insulation scenario all other variables held constant. Please thank you.

Gteat vid. As you have open energy Mon. How do the figures compare with the ones on the vaillant controls? Energy Yeild and working figure?

Hi just checked mine today and if the controller is accurate it says I have used 17.1kwh of power and produced 101kwh of heat that's nearly cop of 6 at 5.5 degrees ambient. House is at 20 degrees. Who said you can't heat old houses with a heat pump. It's running at a flow temp of 35 degrees to keep house at 20. We'll chuffed best thing I done getting rid of oil boiler! Your videos have been a great help. Thanks

Great video! What did changing the weather compensation curve from 0.8 to 0.6 mean in terms of flow temperature? I figured that the flow temperature at 0°C outside changed from at 47°C (0.8) to around 38°C (0.6). At the moment the outside temperature is about 12°C, so the flow temp should be about 28°C (curve 0.6) or 30°C (curve 0.8) so very little difference. The difference becomes larger at lower outside temperatures. I would love to see a video with snow on the ground, what will the flow temperatures and COP be then?

can we get or make temperature more hight by using Heat pump ??

@HeatGeek the emoncms Link doesn't work anymore - might be worth updating to the heatpumpmonitor URL?

Nice work! Did you do anything special (calculations etc) in emoncms to get from the inputs to feeds or is it just logging to feeds? btw, have you installed fans on the radiators?

Really interesting, so would having very oversized radiators give better efficiencies or does it mean you can install a lower powered heat pump? Looking at replacing a radiator in my living room now and maybe upgrading the boiler in a few years and debating on heat pumps vs boilers. So if I oversize the radiator now will this help from the efficiencies point of view? Basically can a radiator be too big?

Hello, what setback and target temps are you using and how are they scheduled?

What are your lowest temperature in winter? Seems like its quite warm and perfectly suited for a heatpump. Im recently looking into it but it would be viable only for using when outisde temperatures are above 5c, since i alredy have gas that is not too expensive, and since heatpump wouldnt make sense for -15c anyways

For the confused, improving insulation will not improve the CoP, the CoP is purely a measurement of how efficiently the heat pump is working, however if improved insulation means you can reduce the flow temperature/compensation curve then that should improve your CoP

I"m guessing also that you're mainly heating the office in the daytime - so you don't have the problem of lower evening/overnight temperatures to contend with. A lot of domestic systems will be working hard early in the morning and from early evening to midnight when the outside temperatures are lower - so perhaps the COP would be likely to be lower? Or are you leaving the system on 24 hours a day?

Might be interesting to see the cost difference between heating with the pump vs heating with a combi boiler.

Hi, is your Delta T between 3-4 C.

So according to your live feed you are using about 30Kw in electric per week on heating. At say 38p per Kw = £11.50 per week to heat your building. Is this correct ish?

Yes! Disrupt the system, love it.

so do you just put bigger radiators in?,,is that it?anyone?

What was the cost of the installation and also the running cost in £ compared to your previous system for most customers efficiency really means cost

Can you share your control strategy in more detail? Would be really helpful to replicate. Thanks

Great video with lots of info as usual! I am not in UK so cant benefit from your services, and planning to switch to a Vaillant hybrid setup for my fairly insulated(roof, and walls insulated and have hr++ glasses in every room, need still change some radiators, there is not much i can do for floor insulation but there is at least some) 130 years old home. I changed the 20 years old boiler to a Vaillant ecoTec exclusive VHR CW5+ 34/43, and now i am able to measure my heat demand. I thought about using your open Energy Monitor the COP values for similar HDD valued days can give me an estimation about my possible energy consumption if i switch to a heat pump. Do you think it would be logical to use that data?

Awesome videos. Thanks so much for sharing this information. Like some others here, I have an Ecodan. Is there any chance you can share some comparable settings?

How is the cop calculated?

No-one else seems to have talked about this, or you. Can you tell me the diameter of your heating system pipes in this building? Would having smaller/larger ones make a big difference to your results?

Just to clarify, is the solar thermal contributing to the heating, I know you had problems initially but are they sorted now?

When using ground source heat pumps, is there a temperature cut off point? Ie if there was too much heat pulled from the ground or other source, would this negatively impact the efficiency due to the refrigerants used? If not could you combine waste water heat extraction with the heat pump, reducing the required amount of land you'd need to use and reuse more of the energy you've created. Significantly reducing outlaying cost and making this more accessible to people with less land. I would love to chat about this with someone in the know.

Will adding more insulation not actually drop efficiency? I'm finding with our Mitsubishi that with low flow temps it tends to cycle more as heat loss is too low to keep the flow/return delta large enough. It's on less often, so less overall energy use, but the efficiency is less.

Why does the amount of insulation effect cop? I would of thought it would just effect total energy usage which is a very different thing?

How will the system cope with prolonged -20 ish temps which we had a 3 or 4 years ago when the beast from the east hit?

Hi guys, I live less than a mile from your office, I've got your Vito Ops manager coming to see me next week. My current gas heating/insulation is dreadful, I want to improve everything and install a heat pump. If you want to use me as another real life case study feel free to get in touch! Thanks, love the channel, couldn't believe you were so close after I'd watched half your channel 😂

What I would like to know is why can’t we use swimming pool heat pumps (the all season units) rather than the over priced “house HP”. I understand they may not reach higher than 40c but the efficiency is massive on them up to 25 COP. By using a swimming unit with a heat exchanger this should do the job better than most purpose HP units.

Interesting your links show a heat output of 11.2kwh for 2.7kwh input .. if that 11.2 was the equiv of the gas calc and gas to electric is 3.5-4x cost .. the overall monetary saving is negligible .. surely .... or am I missing something key here

Hi Adam, My Daikin Altherma 2 is set to 25(@20deg ext) and 50(@-2deg ext)*. How does this compare with your 0.6 setting. Average COP since June is 4 for heating and 2.5 for Hot Water based on controller readout. Love the videos

The issue with these though is unless you have solar panels running them they are basically as expensive as a combination boiler but double to treble the purchase price . Who has 20k to fit a system ?

We have a similar 7kw arotherm. Just checked the working figure which vaillant elude to being cop. It's reading 7.1 for heating for November so far and 4.2 for dwh. Seem too good to be true. Although have tuned it carefully to get there.

I would like to see some details of your OpenEnergy monitoring equipment. Measuring energy input is easy, just needs a Current Transformer on the live feed to the heat pump, but how are you measuring the heat produced?

So it may be better in some cases, to just invest in some bigger radiators instead of insulation. Just to try to maximize scop, instead of lowering heat loss right?

This is from a heat source calculator for a house of my age , For every sq ft of living space, you need about 30 BTU of heating output. That means, for example, that for a 1,000 sq ft home, you would require a 30,000 BTU heat pump (that’s a 2.5-ton heat pump)., so my heat source pump for my house is 60000 but with a weight of 5 tonnes, so how is that going over my roof then

You may have answered this somewhere already but why go for a heat pump isn't the thermodynamic panels more efficient as they don't require a fan? Just curious cheers

Hi Adam. Again great video !! Questions: is your system being helped by solar ? I assime it does. Because 5.9 is above any HP specs, right ? What is the COP for your Vaillant HP, from their specs, at the avg Nov temps? The last one: what is the min output kW for the HP? Keep the videos “flowing” 😊

I’m concerned about the environmental damage caused by f gases. I understand there are alternatives that can be used. Could you do a video on where the industry is at with this issue? If heat pumps do take over gas eventually, I foresee this being an issue that the industry does eventually get round to tackling. Does it not make sense to get on with it now? Thanks

Hi I was thinking of doing my acs gas course so you think this is worth it in 2023 or should I study something else. At the moment I work as a plumber

How did you get emonhp to work with heatpumpmonitor. I don't see all these nice fancy charts like on here. Octopus Energy fitted my Open Energy Monitor but it's not set up properly I don't think so I cannot see any of the costs / savings the heat pump is producing.

Did you say what temp you had the thermostat set? In other words was the place a realistic temp of say 21.

@HeatGeek no new data showing for over three months?

If I could run one of these off of my home storage battery which cost me 4.5p/kwh at the moment, then I'd be looking at

Once it's insulated properly it might benifit from a lower capacity heat pump to keep it running near its maximum.

Not bad 💪 my Vaillant arotherm plus has a scop of 5.3

Summer temps you've got down south just now Fella lol

I have just been studying your data on Emoncms it looks like your heat pump is cycling quite a bit, I would think if you can stop that it would be even more efficient. Thanks for the video I love your channel.

The worse your insulation, the higher your SCOP will be, assuming you can still heat adequately with a low flow temperature, because your balance point temperature will be higher i.e. a larger proportion of your annual heating load will be when it's milder outside and hence the COP higher. A house with a really low heating load will have that load concentrated on the coldest days.

If you increase insulation remember you have to improve ventilation. If so put the outdraft against the outside unit. Energy recovery. SMe goes for shower drain Water lots of energy loss there.

Could you explain the reasoning for target COP number as the measure of successful performance ? yes it shows the very efficient use of electric Vs direct gas heat but surely it is the total electric energy consumption reduction that should be the target. So when you install insulation total heat demand goes down and hopefully electric consumption. Should that not be the target to encourage?

I saw your readings was up and down as though it was turning on and off, is this correct?

If you are in a very wet area please do not fill the cavity on old properties with anything that can become slowly saturated.

Your COP values are very impressive, partly explained by your low flow temperatures. However, your building seems to have an extremely low heat loss, despite the lack of insulation. Using the figures from 30th November, your heat pump generated 54 kWh and consumed 12kWh giving a COP of 4.5. The internal temperature never dropped below 20 deg C with an average external temperature of around 6 deg C (difference = 14). The average heat loss during this day was 54/24 = 2.25 kW which gives a value of 160 W for the heat loss per degree difference between internal temperature and outside temperature. This seems very low for an uninsulated house (mine is 450 W). Having said that, I doubt if many ASHP owners get a COP of 4.5 when the outside temperature is 6 deg C, however low their flow temperature. How are you achieving this? No buffer tank for one thing probably.

Is the open energy monitor still working?

Well it's easy to get this results then UK is warm. I would like to see numbers starting from -10 C to -25 C

You certainly don't need a new well insulated house for a heatpump to work or make sense. I own larger timber framed house from 1732 in New England where mid winter nights are regularly -10c or colder. We have an air-to-air heatpump that keeps indoor temps at 20c down to around -12c. We have a backup furnace that will kick on below that, but ultimately that's generally only running a few hours on cold nights in mid winter. Our loft insulation is basically what you showed here, whatever fit in between the joists. We do thankfully have some blow in cavity insulation, but our exterior walls are thinner than modern homes and aren't air sealed, so its still far from being well insulated. Granted if we lived in an area with gas service that would almost certainly be cheaper, but in our semi rural town the only fossil fuel choices are heating oil or propane.

@heatgeek Is it possible to calculate the SCOP over time without installing the open energy monitoring system? Their system is fantastic but it costs 10% of my ASHP install and I can’t afford it.

The problem is the education of system designers. Still a real gamble get the wrong company and you'll be paying for it for the next ten years. Great videos as always.

Why are rads still rated at dt50 and dt70 when you should be running dt35 or less really to cope with the new 55deg flow temps required It makes finding rads more hassle than it needs to be!

stats are down?