SteamyTea Posted August 1 Share Posted August 1 11 minutes ago, Dave Jones said: How can you size rads and a heatpump without doing heatloss calcs How? Link to comment Share on other sites More sharing options...
Marvin Posted August 1 Share Posted August 1 (edited) 4 hours ago, TheMitchells said: As ours will be on the ground, I read that under the front window would be acceptable. Hi @TheMitchells I think your right on that point, however, consideration has to be taken of the first lines of the planning regulations as well. ....provided ALL the limits and conditions below are met. This includes the MCS 020 requirements page 15 onward: https://mcscertified.com/wp-content/uploads/2021/10/MCS-020.pdf I could not say if the ASHP will meet those requirements, especially, as it has not been identified yet. Good luck Marvin Edited August 1 by Marvin minor change. 1 Link to comment Share on other sites More sharing options...
sharpener Posted August 1 Share Posted August 1 23 hours ago, TheMitchells said: That seems a large ashp for such a small building. Too right it does. For a rough estimate see this cheat sheet. Our 200 sq m stone barn conversion is currently having a Vaillant 12kW unit installed as I write, a 14kW Grant sounds totally OTT for a smallish bungalow. Over-sized HPs are not only unnecessarily expensive to install, but are also inefficient in operation so running costs are higher as well. Link to comment Share on other sites More sharing options...
TheMitchells Posted August 1 Author Share Posted August 1 Hmm, the chap wh came to look at the place today was very scathing of such a high HP. He said we'd be looking at a one around the 7 mark, taking the floor at less than 100 square meters and a basic rate of about 70 - not sure what the 70 was but he was looking at the windows/walls and giving a broad estimate. He also siad they onlyuse Steibel eltron who provide the whole system, so it all works well together and has space for expansion should we want to add ufh in the future. have to admit that i liked him - he's local and said straight off that if we went for him, it wouldnt get done till end of September ish. So just waiting to get quote from him now. I did give him all the window/doors sizes and floor plan and he asked me to get an up to date EPC. The current one was presumably done when we bought the place in 2018. CVC got back to me but the quote was far more than the first quote without any deetails from us. So they are out of the running. Fingers crossed that the second guy gives a reasonable quote. 🤞 Link to comment Share on other sites More sharing options...
JohnMo Posted August 2 Share Posted August 2 7 hours ago, TheMitchells said: Fingers crossed that the second guy gives a reasonable quote. 7 hours ago, TheMitchells said: Steibel eltron who provide the whole system, I guess £10K plus your grant. Link to comment Share on other sites More sharing options...
PhilT Posted August 2 Share Posted August 2 8 hours ago, TheMitchells said: He said we'd be looking at a one around the 7 mark, taking the floor at less than 100 square meters and a basic rate of about 70 - not sure what the 70 was but he was looking at the windows/walls and giving a broad estimate. peak heat loss of 70 watts per sq m, times floor area 100sqm, = 7,000w heat pump required Link to comment Share on other sites More sharing options...
JohnMo Posted August 2 Share Posted August 2 32 minutes ago, PhilT said: 7,000w heat pump required Or a heat pump that delivers 7kW at your design flow temp and your outside air design temperature. Plus an allowance to heat DHW. Allow 2 hrs for DHW, would require the heat pump to be able to provide heat to home in 22 hrs. So (7x24)/22=7.6kW. Link to comment Share on other sites More sharing options...
Dave Jones Posted August 2 Share Posted August 2 £4k installed with a tank is doable. https://www.theheatpumpwarehouse.co.uk/shop/heat-pumps/air-source-heat-pumps/7-kw-panasonic-aquarea-high-performance-mono‑bloc-j-generation-1-phase-r32-wh-mdc07j3e5/ Link to comment Share on other sites More sharing options...
PhilT Posted August 2 Share Posted August 2 On 31/07/2024 at 17:43, Mr Punter said: The EPC says you only have 100mm loft insulation. Top this up to 300mm and it will pay back very quickly. not forgetting this very important piece of information. Could reduce heat loss by 25% - 35%, so 7.6kW heat pump could be reduced to only 5kW - 6kW 1 Link to comment Share on other sites More sharing options...
ReedRichards Posted August 2 Share Posted August 2 Can I just mention that there are no economic benefits of having a mixture of underfloor heating and radiators, particularly in a small property when there is little point in having multiple zones. If you like underfloor heating and don't mind digging up your floors to install it then all well and good. But the heat pump will need to make the water hot enough to meet the requirements of the radiators and it is how hot that heating water needs to be that determines how economical your heat pump will be to run. Unless you have really large area radiators they will probably want hotter water then your UFH could get away with but if so then you need that water hotter. 2 1 Link to comment Share on other sites More sharing options...
JohnMo Posted August 2 Share Posted August 2 7 minutes ago, ReedRichards said: Unless you have really large area radiators they will probably want hotter water then your UFH could get away with but if so then you need that water hotter. Plus you have to run mixer and another pump due to the flow temperature difference. Unless you do dT15 radiators and flow a max of 35 degs Link to comment Share on other sites More sharing options...
sharpener Posted August 2 Share Posted August 2 21 hours ago, TheMitchells said: He said we'd be looking at a one around the 7 mark, taking the floor at less than 100 square meters and a basic rate of about 70 - not sure what the 70 was but he was looking at the windows/walls and giving a broad estimate. If you haven't got double glazing that might be a cost-effective improvement (after increasing your loft insulation). 21 hours ago, TheMitchells said: He also siad they onlyuse Steibel eltron who provide the whole system, so it all works well together and has space for expansion should we want to add ufh in the future. Stiebel Eltron are an expensive brand and IIRC they will only sell them with their own hot water cylinders increasing the expense still further. Link to comment Share on other sites More sharing options...
TheMitchells Posted August 2 Author Share Posted August 2 28 minutes ago, sharpener said: If you haven't got double glazing that might be a cost-effective improvement (after increasing your loft insulation). Stiebel Eltron are an expensive brand and IIRC they will only sell them with their own hot water cylinders increasing the expense still further. yes, we have double glazing and they arent too bad. The chap did say the het pumps from Stiebel Eltron are more than others but he feels they are worth the expense. We dont have too much loft insulation at the moment, minimum required, i believe but we will add more as soon as it is all installed. All the pipework and stuff will across the loft and drop to the required location, so we can then add the extra insulation on top of it all. Link to comment Share on other sites More sharing options...
TheMitchells Posted August 2 Author Share Posted August 2 4 hours ago, ReedRichards said: Can I just mention that there are no economic benefits of having a mixture of underfloor heating and radiators, particularly in a small property when there is little point in having multiple zones. If you like underfloor heating and don't mind digging up your floors to install it then all well and good. But the heat pump will need to make the water hot enough to meet the requirements of the radiators and it is how hot that heating water needs to be that determines how economical your heat pump will be to run. Unless you have really large area radiators they will probably want hotter water then your UFH could get away with but if so then you need that water hotter. I'll ask him when I next speak to him.. And I guess if it more efficient, then I can make do with extra radiators. Link to comment Share on other sites More sharing options...
ReedRichards Posted August 3 Share Posted August 3 On 02/08/2024 at 21:44, TheMitchells said: And I guess if it more efficient, then I can make do with extra radiators. Extra radiators aren't more efficient in terms of running costs, they are equally efficient to a mixture of radiators and UFH (in your circumstances). But I imagine that extra radiators would be much cheaper to install than UFH. 1 Link to comment Share on other sites More sharing options...
Beelbeebub Posted August 4 Share Posted August 4 The other option is fancoil rads. I've been trying out a reverso fancoil. Not been able to fully test it as it was installed in the spring and it hasn't been that cold, but (when set to minimum) very quiet and seems to punt out quite a bit of warm air at 40C flow temp. Had to do some fiddling to get it to work with my system - it is replacing the failed UFH in a room, but so far so good. Link to comment Share on other sites More sharing options...
Dave Jones Posted August 4 Share Posted August 4 (edited) 29 minutes ago, Beelbeebub said: The other option is fancoil rads. I've been trying out a reverso fancoil. Not been able to fully test it as it was installed in the spring and it hasn't been that cold, but (when set to minimum) very quiet and seems to punt out quite a bit of warm air at 40C flow temp. Had to do some fiddling to get it to work with my system - it is replacing the failed UFH in a room, but so far so good. its not the fancoil its the heatless that needs working out first. may find just a slightly larger double rad is plenty. all guesswork followed by a thread in 6 months 'this heat pump costs a bomb' unless they are done properly. Edited August 4 by Dave Jones Link to comment Share on other sites More sharing options...
IGP Posted August 4 Share Posted August 4 7 hours ago, Beelbeebub said: The other option is fancoil rads. I've been trying out a reverso fancoil. Not been able to fully test it as it was installed in the spring and it hasn't been that cold, but (when set to minimum) very quiet and seems to punt out quite a bit of warm air at 40C flow temp. Had to do some fiddling to get it to work with my system - it is replacing the failed UFH in a room, but so far so good. Ah I’ve been looking at them for cooling as part of my ASHP plan for next year. Hopefully the build quality is decent? Link to comment Share on other sites More sharing options...
Beelbeebub Posted August 4 Share Posted August 4 5 hours ago, IGP said: Ah I’ve been looking at them for cooling as part of my ASHP plan for next year. Hopefully the build quality is decent? Reverso fan coils seem reasonably well built - the cost is fairly high though. One thing to note is they have obviously been designed for their home market (Italy?). The mounting system is not like the UK rad hangers. You have to mount directly to the wall, which makes for almost zero adjustment for getting them level. You have to be dead on with your drill holes. Also the pipe entry on the bottom isn't quite right for the standard UK pipe clips. The pipes have to kink a bit awkwardly to get round the frame. Noise wise, the standard setting is audible, but not loud. You can change some dip switches to lower the speed and at the bottom end (200rpm) it is near inaudible. Your output is lower (obviously) but still many hundreds of watts. Might be over 1kw I'd have to check. Link to comment Share on other sites More sharing options...
MikeGrahamT21 Posted August 5 Share Posted August 5 On 02/08/2024 at 21:43, TheMitchells said: yes, we have double glazing and they arent too bad. The chap did say the het pumps from Stiebel Eltron are more than others but he feels they are worth the expense. We dont have too much loft insulation at the moment, minimum required, i believe but we will add more as soon as it is all installed. All the pipework and stuff will across the loft and drop to the required location, so we can then add the extra insulation on top of it all. Why not get what you can from the government schemes with regard loft insulation, whilst your parent(s) are living there? They may even qualify for free solar panels if there is enough allowance left. 1 Link to comment Share on other sites More sharing options...
haythorn_1 Posted August 8 Share Posted August 8 I had the initial quote back from my local MCS installer (before they've done a survey). I am doing an extension and refurb so will be installing UFH as part of that, so this should be a relatively simple install with no emitter upgrades. This is the quote I got back Insane! Now I see why everyones suggests to not go down the BUS route, but just seems wrong to me. Link to comment Share on other sites More sharing options...
JohnMo Posted August 8 Share Posted August 8 Obvious things Joule high gain, isn't a heat pump cylinder, not the coil is really big enough. £5.5k for parts and fittings, should a high. They are connecting to your UFH? No survey, how do they know you need 12kW. Think 80% of all UK property is 6kW and below. Link to comment Share on other sites More sharing options...
haythorn_1 Posted August 8 Share Posted August 8 On the heat pump selection I would give them the benefit of the doubt as I just provided basic information to have an initial quote. But ignoring that the other elements seem insane. Is basically £10k for installation with the parts required. All they need to do is site the ASHP and cyclinder, connect them together and then join to the UFH and DHW. More just sharing to show how much these companies rip you off. This was the best rated in our area. Link to comment Share on other sites More sharing options...
JohnMo Posted August 8 Share Posted August 8 5 hours ago, haythorn_1 said: I had the initial quote back from my local MCS installer (before they've done a survey). I am doing an extension and refurb so will be installing UFH as part of that, so this should be a relatively simple install with no emitter upgrades. This is the quote I got back Insane! Now I see why everyones suggests to not go down the BUS route, but just seems wrong to me. If you go on to City Plumbing site they a build your heat pump package, (based on knowing your heat loss or they have a calculation tool) so you can get an a idea of what parts are involved and the true costs. Just deselect the buffer and secondary pump. Link to comment Share on other sites More sharing options...
TheMitchells Posted August 20 Author Share Posted August 20 The original company are coming tomorrow to do a heat loss assessment. They said it can take up to 4 hours. Will report back once I have it. 1 Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now