Post and beam

Thanks. 28mm with perhaps a thick insulation layer then rather than a thinner insulated 32mm

What is the detrimental affect of too big a bore pipe, if any ?

8 metres in a direct line so a little more than that to account for the Bends at each end to get up through the block & beam. Thats 8 metres to the manifold under the stairs. 7kW Vaillant

I have seen 32mm pipe pairs in 125mm, 140mm and 160mm so far. For a relatively mild Hertfordshire installation is it necessary to go for the thickest insulation or is this overkill. Dont want to skimp on this element.

High JohnMo Perfect, thanks. Just as i thought really and totally negates the 45 degree UFH flow temp nonsense i have been arguing with what i thought was my chosen installer. Both halves of the system at the same temperature was their mantra.

Dam, i need about 8 but you are a long way from Hertfordshire.

Following on from my other thread about my concerns with a potential installer. How does the ASHP deal with heating the DHW to a suitable temperature? i guess it runs for a short period at 50 ish degrees and then reverts if required to the lower flow rate for the floor. If correct then we need some hours in the day free from UFH heating to do this job. Have i understood it well enough?

Thanks Dave. That makes perfect sense of course. I wonder how that works for the fitting of a 3.1 metre Bi fold?

I have been made aware of this term today in the context of Window & door fitment and the requirements of the scaffolders. 'door to be ladder beamed' I was trying to understand what modifications need to be made to the scaffolding to allow the glazing to be installed. Thanks in advance as always guys

Thank you

What is the source of this chart please? I would like to look at different tog values or at least the relationship it has on sliding the scales

That is seriously impressive

My main concern is the efficiency

I know, i was illustrating the fact that they dont appear to know what they are talking about. This was not their technical guy so i am giving them a chance next week to see if they can say anything to restore their credibility.

During a conversation with these guys this morning, when i questioned the flow temp and pipe centres i was told that 150mm centres might result in too much energy going into the floor resulting in cycling. They dont appear to grasp that that would be true if they stuck to their 45 degree flow temperature but would not be true if the flow temperature was reduced to a suitable value!! If i can find a company that will just install the ASHP/UFH and ignore the grant i think i might do that. Easier said than done though.

I have looked at it again and it is indeed as you say a calculated figure and not a slip of mine on the keyboard. I have to assume its correct. Yes. And yes i am. But i used 1 in case my score is not actually any better when i get that far.

Then that is clearly a mistake i need to check. The wall value is .16

I need to look again at my spreadsheet because the house is 201 sq metres, storey and a half.

I found and have updated with some missing windows i forgot last year. Would anyone that understands the spreadsheet please look at these numbers and give their views. Heat loss - Caxton j DG 5 Sep 24.xls

Some time ago i tried to do my own heat loss calculation using the spreadsheet on this forum. I dont really know if i have done it correctly though and therefore have no confidence in the numbers. They may or may not be valid. But now i also dont have confidence in this proposed solution. I have a full design SAP calculation from Potton so it should be possible to generate a good set of data via the spreadsheet.

John Mo Well, there are other questions that i did not include in the original post. I have consistently said i want a flow of <35 degrees and ideally no more than 30 on 150mm centres for the ground floor only UFH. They have designed for 45 degrees flow on 300mm centres which is beginning to make me worry if A: they know what they are doing and B: have taken into account what i have asked for. In fact, also C Have they understood the design of this Potton house. Yes i have written back to them asking for clarification. I do not expect to need radiators upstairs at all and certianly not large ones. I have also always said i want single zone

I have just had a heat loss calc done by our proposed supplier of UFH & ASHP. With regard to the emitters, they have a term '3.1 (HEG) ' . Quite apart from not expecting to need emitters of the size they specify which is a question i have raised with them. Can anyone shed light on this please?

I am looking for any recommendations for an Alternative to the DNO in north hertfordshire. If anyone has first hand knowledge i would love to hear please. Keith

I managed to get Selfbuild zone to split out the 'inspection fees' bit and its £2850 for the Building control inspections. So i have dropped that from their offer and engaged the local authority building control becuase they are £1000 cheaper. However Selfbuild zone also want 'a Plan Check and up to 5 Technical Audits to be carried out by a surveyor nominated by BZSS'. This, to cost about the same as getting the local authority building control inspections. It appears to me that i am paying twice for the same service. Unless any of you knowledgeable people can explain what the difference is between a Technical Audits and a build control inspection. Confused and feeling slightly bent over by this

quote is in their pipeline, curious now to see the numbers.