Clive Osborne

Thank you. Some bed time reading

Yes I understand that's pretty typical but some use it directly in a all in one heat pump cylinder

Do you use the heat extracted ?

I will find the blank spreadsheet and post it on here. It had parts about being open to the elements.

That would explain it. Certainly in the case of combi boilers.

That's very true I have seen some shocking ASHP installs where they have left the emmiters as per the gas boilers they replaced them with.They run at 45C and then wonder why people complain . How do you calculate air changes in @SteamyTea last numbers.

No it's a room by room heat loss tool it just uses standard degree days etc to compare guides on running cost based on the results.

You probably heard a wooshing sound as a lot of that went over my head. But I will go through it all again

Purely guide on running cost

@JSHarris what are your thoughts on this ? Its electric storage heat at 12 watts per sq meter for a 1987 build. It goes against what I have been taught. But as I said before every day is a school day ! Its interesting for sure. Is it really that simple ( not the working out part I appreciate that's beyond most people ) but the principal? Do we go overboard on sizing ? I have seen some huge KW oil boilers in relatively small places.

Exactly that reason comparison to ASHP Biomass FIR GSHP running costs. Just a guide for people no other reason. Been a while since I have done one to be honest.

I was born on Somerset I am not in a position to say anything

I will look at the spreadsheet and send over my last heat pump version

Of couse it will be interesting although it's the air heating market and off gas grid we concentrate on until they release the next version of SAP . We obviously go above the heat loss level but I still cant see a 1987 house with storage heaters heating air at 12 watts per sq meter heat loss even in Devon. Its certainly ended up an interesting post after a rocky start ! If you are ever near Andover it would be good to meet. Every day is a school day !

Regardless I got it wrong anyway ! I was thrown by the 13,500 figure. Apologies. So if you have 1.2KW of heating I make that 25 watts psm going into the house. I would have to so a full heat loss calc for what is going out. I would never go that low on a 1980s build unless it's been seriously updated. Regardless of the form of heating even an ASHP but that's just my opinion. At 12 watt psm I would say that's passive standard.