MikeSharp01

Just poking this thread as it looks like there is now an API and a home assistant integration but no Homely integration. We are being offered a vailliant heatpump for our DHW / UFH and I would like to make sure that I can get control of it. Anybody got any experience of the vaillant API development groups work?

It's a mine field, we have the same problem although our tracks will run above the beams in the vaulted ceiling and are really for lighting pictures rather than the space more generally. I have found no standard although I have to say its not been a long look as yet. I did find this https://www.thelightbulb.co.uk/resources/everything-you-need-to-know-about-track-lighting/ which gives a hint about different track styles and is generally very informative. I think the solution must lie in looking at commercial shop fitting lighting tracks as they seem to have all manner of things on them. Either way it will be interesting to see if anyone can identify a standard track which can accommodate lights of many different manufactures.

Yes what quantities are you looking for - roughly, including lengths of steels & sizes will help members get a better handle on the prices you have given.

Hi and welcome to THE forum. I have no experience of CiL, our LA does not have it, so I cannot help but there have been loads of members that have been through it so you should get some advice when the world wakes up

I just made some temporary frames from 50x25 batten and covered them in clear polythene.

We did it that way. I was taking so long to line up a window company that I decided to go ahead without them and seal up the holes as best I could. The way our air tightness is done is basically to have the whole house sealed internally with Intello+ and I ran this over the roof lights as they were in because the roof was on. I left the window holes though so I had to make temp covers for them. We then pumped the cellulose fibre into the walls through the intello+. The windows are now in so all I am doing is taping round them and fitting the sub structure for the internal window boxes. I still have to seal the intello+ to the slab which is my next job. The first air tightness test should be by the end of the month but for that I will leave the roof lights covered so I don't have to worry about them.

O It is somewhat about volume / surface area because you could have a 156m on the ground floor with 50m ceiling height and 100m 1st floor - extreme I know but I guess you see the point. Pretty sure it won't make difference though will it.

Have you used / tried the JSHarris spreadsheet? You can find it here along with some details for using it.

You do wonder, on the up side this morning we had a visit from our 4th potential installer of our system and he had actually done his homework, knew it was a passive class house (we may get it certified / may not) and took me through a couple of issues they had with bits of it in an intelligent and switched on way, explained the various control regimes I could have - Homely, direct, Wunda and a Vaillant system direct to their proposed ASHP which was the 3.5kW unit - the size I think we need. I also already sort of know what I want everywhere and he was happy to take me through how they might be able to accommodate, and what I might want to look at for balance - now all I need is the quote! I will let you know how that goes.

But oddly Surely not - but your observation is valuable and has resulted in my editing my post to better reflect the reality of units now.

This appears to be a very common issue - we are having it as well. The calculations, done with the Passive House Planning Package (PHPP), for our build shows we actually need about 1200W to maintain a dT of 22oC (K) (-2 OAT to 20 IAT) but we are being told we need an 8kW ASHP by one potential supplier and 6kW by others which to me is madness. However we do need to take into account the DHW needs which will need factoring into the size of the ASHP so I think I need a max size ASHP of 5kW and could quite happily live with 3.5kW.

Your'e right I should have said openable shouldn't I. Thanks for the insights the whole thing is a pain but one thing I have learned is that I like the look of the KRONOTERM heat pumps which one of the companies has quoted to fit - expensive but nice, although I have no idea of their quality / performance the do quote the sound level which seems phenomenally low. Image Source KRONOTERM documentation 09.03.2024

Yes and it's about £4k + The VAT which I will get back at the end, so as long as the quote is below around £11k then I will go with it - as long as I trust then and their technology otherwise not.

I know we, the forum in general have discussed this N times (where N is a very big number) but I thought I would start a new thread as a contemporary home for the same old chats we have had already but with a twist - see if you can spot it. We already had the discussion about having to be at least as well educated as your supplier if you want to get the system sized & designed properly for your house. I have also come across a good volume of people who have the most awful stories to tell about installations. There is also the buffer tank / no buffer tank debacle among many other things. We have been going round the houses, trying to get three quotes to do ours. Here is where we are: It's designed to be a passive house (PH) although we probably won't certify it. I did the design training and have built the whole thing around the PHPP with the architect. The Brief: We need someone to install and MCS certify, so we can take advantage of the grant, a very small list of things: 1. A UVC 2. A Heatpump 3. The plumbing for those two and our UFH which is already in the slab. 4. The controls for the above - no use of cloud systems and all systems OPEN. Background Information: (Given to all the suppliers) We already have the UFH pipes sticking out of the slab, 28mm Flow and return pipes from the utility room (UR) to the ASHP base, suitable cabling for almost any ASHP on the market from the ASHP back to the UR with room in the duct for more if needs be. The UVC will be 2.1m from the UFH header around the utility room wall. The PHPP says we need 10.288 kWh/(m2a) the TFA (Treated Floor Area) is 139.4m2 - the actual area is about 156m2 but TFA is the metric PHPP uses. Based on the above you can imagine we have good insulation - the air test is still to come but I will work at getting that well below 0.6 ACH (PH metric) SO I think I can stand by the PHPP outcome - it is roughly in line with other similar sized PH dwellings discussed on here. They all received the PHPP verification page, a full set of the Building Control (BC) drawings, the U values for the walls, the roof & slab along with the average Uw value for the window and roof-light packages (Triple and Quadruple glazed respectively) and a layout plan of the utility room showing where everything needs to go and the dimensions allowed for. To date we have had two indicative quotes (IQ) (Which are in themselves something of a conundrum because my understanding of a quote is that it is fixed - so not indicative.) The first company sent a chap to visit, he spent 10 minutes looking at the house and left - sending me a quote within 3 hours. No information about the units (brand / size / control ability / etc). The second firm we found via the famous site who seem, judging by their Youtube channel, to know their stuff and are certifying installers who take their training. They did not visit but worked off, or not, the information package discussed above. I won't share the quote but here are a couple of comparative sets of numbers to look at: First - the PHPP verification page - (True this is as designed but all the insulation is in as are the windows - just air tightness to confirm) Then the heat load response calculation by the second potential supplier on which the 2nd quote is based - How can these two be so far apart? From my perspective the laws of physics tell me that if you put 8.4kW into the house I told them about you will definitely cook it! Yet the IQ (Oxymoron perhaps) seems to want to tell me that the house is 1.5 times as big as the drawings they were sent and consumes about 2.5 times as much energy as the best estimating system on the planet for such things (other of course than the JSHarris Spreadsheet) thinks it will. They also want to fit a buffer tank and I have not allowed for this in the utility room - cos I could not see I would need one and still don't think I do! So what have I missed - like a huge heat sink / cold bridge or three that I forgot to put into the PHPP, perhaps a couple of rooms I have forgotten I have built or their assumption that with all this insulation we are still just going to let the air out via trickle vents (big ones) rather than use the MVHR which is clearly shown in the drawings and accounted for in the PHPP? It makes you wonder and so it looks to me like I need to kiss a few more frogs! Are we allowed to say such things here! I mean I don't mind if they turn into a princess or a prince I just want them to make me feel like they know what they are doing!

Yes this is what @TerryEdoes only using Willis heaters. His decrement delay, like yours & ours I suspect, is very low so it matters not that we don't run the thing full time and anyway at some point we will need to put some of the the output into the DHW - which is now going to be a UVC (or some such water filled device) because I cannot get happy, given discussions here and elsewhere, with the Sunamp unit I had originally thought I would use. Talking of DHW I have been wondering how best to control around that. We will have about 6kW of Solar so I am thinking I would want to top the UVC with that. Obviously the ASHP is the best thing to do that with, given the COP, so feed the ASHP with power from solar when the sun shines BUT once the ASHP reaches its max temperature switch over to the immersion heater fed by the Solar to give us some more stored energy.

Looking at our numbers and worrying about sizing our heatpump I cannot see a 5kW unit modulating down enough to manage a continuous delta of 5degC across our UFH a 3.5 kW might get close but is getting marginal on the DHW side of things.

Here is ours same basis - seems ok to me - its not a Passive house above 0.6 anyway. Pressurisation Test Result (ACH) Specific Space Heating Demand (kWh/m2a) Monthly Method - [Annual Method] 0.2 10.3 [10.9] 0.4 10.5 [11.1] 0.6 10.7 [11.3] 0.8 10.9 [11.6] 1.0 11.1 [11.8] 2.0 12.2 [13.0]

ooooops.

Absolutely - let's hope we here are not contributing too much - lets get back on topic - whatever that is given how far this one has wandered over 5+ pages.... Sorry @Nickfromwales

You could but you would soon either have it overwritten or asked to provide your evidence / citations/ references. I dimly recall it was compared with encyclopedia brittanica and its veracity score was similar.

only going to cause condensation if the temperature varies wildly, if it is still in its packaging then even that shouldn't be a problem.

Obviously you are not observing this meltdown at the speed of light that is happening among our elected representatives - perhaps it has not reached Cornwall yet, I mean it is light years from the center of power after all.

I guess it's all about how the contractor sees it. I have run the flow and return pipes (28mm), put in the ufh pipework, done the concrete base for the unit, pulled in a collection of cables and a few other bits. None of those quoting have said anything - while rubbing their hands with glee at less work for them to pay for.

Hello and welcome to THE forum for people like us Masood.

Yep - I am reminded of my time at Marineville - commander Shaw would calmly announce over the base tannoy that "anything can happen in the next half hour."