UFH heat source?

[shanghaismog]

Might be complicated...

We have a super insulated airtight almost passive house and most of the time we're fine with our woodburner but we're thinking that it might be a real luxury item to connect up the UFH pipes that we laid in the floor slab. Cosy toes 😀

The problem is that we have no gas and I don't really want to spend a fortune on an ASHP.... We have our hot water heating sorted, so we need something only to hear the small amount of water going through the UFH pipes. Does anyone know if we can piggyback on our hot water tank (300l)with a buffer tank or thermal store or something for this? We have constant hot water with our Ecocent.

Probably too specialist for mumsnet, but worth a shot!

Pigletjohn? Anyone?

The amount of energy needed for hot water is a tiny fraction of that needed to heat a house

(e.g. in my case, average 0.6 metres gas/day summer for hw; average 6.3 metres gas/day winter for heating as well. Plus a bit of electricity.)

p.s.

some multifuels have the facility to heat water, I used to have one that heated the hw cylinder and would have done one or perhaps two radiators. I have a relation with a very large multifuel that does the radiators, from memory it is nearly a metre wide. She says now she wishes she'd gone for gas.

Wood contains very little energy per load, compared to coal, so you would be shovelling fuel onto the fire constantly. I found if I was ill or snowed in, I just used emergency supplies of coalite.

If you want to go down that path you would have to find a stove company with experience, it would be fairly uncommon. I can just about imagine it working if you had a cellar to keep the thermal store in.

It's not a normal house though, for example I can heat my front room (6m x 7m with a chunk out of one corner) by lighting a tray of 4/5 candles and keeping the door closed!

With regards to the wood burner, we heat the house simply from the heat of it, we have no heating at all other than this. We don't use it to run radiators (and don't want to).

The UFH is a pure luxury item for cosy toes... The correct solution for the house is to put an ASHP in but I don't really want to down that road for cost and hassle factor reasons, as I'd have to cut through to the outside and mess with my insulation.

It's super insulated and completely airtight so the heating requirement is so minimal. When we got a quote for using the ASHP when we built the house they said we'd need a 50L tank for the UFH. I just think there must be an easier way to heat 50L of water to 30 degrees.... I'm happy to take slightly higher running costs as my PV panels will offset the cost of electricity averaged out.

Any ideas?