Post and beam

The loft hatch size is always going to be the main parameter of concern, followed closely by the weight of the thing i guess. Its more a case not only of space in the utility but the copper around it. SWMBO is nervous of what it might look like so doubling up wont help the situation. If i could convince myself that a 200l cylinder would suffice then the pre packaged one mentioned before fits the bill. It does just look like a fridge after all. Does anyone know the size of the old short round fat copper cylinders we used to have in the airing cupboards as kids?

I had an attempt to use the heat loss calculator kindly available here. I have no idea what good looks like so please critique what i have done. I aimed for 21 c room temp with a range from -7 up through -2, 0, 2, and a few others for the OAT. With reference to whether my designed air change value is 5, 3 or .3 The sap summary sheet (Building Regulations England Part L (BREL) Compliance Report) deffo uses .3 Heat loss - Caxton j 10 Aug 23.xls

Thanks dude, i am so impressed.

Every company i have spoken to regarding ASHP & UFH supply and install has expected to see my Sap report. For a house that does not yet exist what else are they going to use. Or me for that matter?

Good idea, thanks Dude, i am not a plumber i have very little idea. I am just trying to accommodate a cylinder in the least worst location.

Yes. I have had different opinions on what constitutes a cold roof. Hence me saying the space is unheated but well insulated. An issue put forward is that the horizontal nature of the tanks makes mixing of the hotter & colder water less efficient.

Noted and thanks.

So a 5kw heat pump will do the job ? 40% modulation would need to accomodate only .96 kW

For distribution ?

I did think about a horizontal cylinder in the loft. A discussion elsewhere advised against on the grounds of the loft being un heated. Now, it is true there will not be any heating in my loft but the rafters have 160mm+ of Kingspan and are designed at U = .11 Is a horizontal cylinder a terrible idea?

I did think about a horizontal cylinder in the loft. A discussion elsewhere advised against on the grounds of the loft being un heated. Now, it is true there will not be any heating in my loft but the rafters have 160mm+ of Kingspan and are designed at U = .11 Is a horizontal cylinder a terrible idea? Actually i will create a separate thread for this question

If i thought i could be sure a plumber would/could arrange everything in a manner that i could 'package' myself then yes this is a good way forward.

If that is a phase change unit then yes.

We dont have a dedicated plant room in our design. The cylinder is going on the first floor in the 'airing cupboard' as far as i am concerned. Wife not too happy, so the TF company proposed(and had arbitrarily decided) that it should go in the utility room. This takes up space and the pipe work does not fit with the asthetic. So a neatly packaged unit that looks like a fridge would fit the bill. I think 200L is a little small for a 200 m2 4 bed house based on what i have read.

Are there any square section Packaged cylinders at the 250-300 litres size? i cannot find any today. Mitsubishi 200 is the norm i think

Thanks. Our TF supplier put Rationel forward for our design. We are cladding in Cedral on the first floor. This is interesting information.

I am interested to know why you discounted these

Forgive my ignorance but if i want 21 degrees inside and work on an outside temp of -2 can you extrapolate what the requirement is. Isn't 21 and -2 the usual range?

Hi Dan, thanks. Yes i saw it in their brochure 10 minutes after i posted and then went to bed and forgot to edit. Regardless, 10kw is way too big for my house which calls into question their competence. So i think they are off my shopping list.

WiSAN-YME 1 S 5.1 (10kw) . I have been quoted for it today. Way too big which sets alarm bells ringing with the quality of the data gathering of the firm providing the quote.

Apologies if i misled you JohnMo, i meant as a brand. Not necessarily the 8kw model. I will take a close look at the smaller Midea's. However if This line is accurate then perhaps not. But, if this datbase cannot be relied upon then what can?

Going by the graph above i think a Midea is likely to be my choice.

Update to the apparently repeating listed 8 options within my 32 page report. Ap50 space heating Kw Kw/m2 Emissions for regulation compliance .3 5301 26.5 Target emissions 5 6617 33 Fabric energy efficiency .3 6908 34.5 Target Fabric energy efficiency 5 7372 36.8 Energy rating .3 4731 23.6 ECP costs, emissions & primary energy .3 4532 22.6 Energy rating for improved dwelling .3 4730 23.6 EPC costs, emissions & primary energy for improved dwelling .3 4532 22.6 So the 'Target' figures are, for some reason, the outliers. I still dont really understand this yet

If i were to rely on this site for a buying choice , these 3 , from my admittedly small knowledge base, look to be good choices. Other popular models that people here seem happy with fare less well. Which is the reason for my 'if' at the start. Daikin, Ecodan and Vaillant for example in similar power range. The BRE site lists weather compensation as 'NO' for the Riello. Hence my question and this thread.

Yes.