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You turned the dial down on the tank you don’t actually have? You said:
I have a combi boiler, gas? it heats my water? I'm considering getting a heat storage tank for solar.
That’s a legionella risk right there. You never tank lukewarm (tepid) water for prolonged periods if at all.
The principle is correct obviously but I don't think I'm alone in using lukewarm water to rinse a dish, if I am then I'm perhaps immune to legionella because I have done it for years without giving it a thought.
decorative wood burning stove fraternity.
Ha, best line of this thread so far!
Regarding retrofit of an ASHP, I thought this also typically required replacing radiators with larger ones, or switching to underfloor heating, due to the lower supply temp ? So the cost of the ASHP itself is only the start of it.
Thread resurrection.
our combi is perhaps looking to be replaced in the not too distant future, and we are considering (as far as it's been mentioned) moving away from gas.
However, what if anything?
our house is a mid terrace cottage, original build somewhere in the early 1800's, in the 1970's a big box dormer was put on it, removing the roof space. Thick sandstone walls, granite chip render on the outside, uPVC windows put in before we moved in.
When we moved in it was a gas boiler for CH and immersion heater tank for hot water. This was changed out when the boiler was condemned, to a combi.
We also have a PIV system to provide fresh air and maintain moisture levels so the house doesn't go mouldy, and no carpets to help it vent.
hearing some getting on OK with ASHP, grants available to make installs similar outlay to new combi, but I have reservations that it's not going to be a solution for us, in our old cottage.
I think to get it to work, we'd need to insulate under the floors and upgrade the dormer insulation, however I'm concerned that if we did that, the house wouldn't breathe and things will start to get damp. We'd need to make sure we either re plaster with lime plaster, or gyproc in a way to ensure the walls can remove moisture, even then, i don't have a lot of faith in uPVC window trickle vents to do a lot of moisture removal, so we'd likely need to install room vents.
I think the answer is to change the combi for another combi and hope there's an alternative to the current alternatives in the years to come, or I get a lot of work done to get the house feeling warm with a ASHP and have a hot water tank again, oh and return to an electric shower too...doesn't seem worth the hassle unless we have a windfall to completely strip out the lower floor of the cottage!
Regarding retrofit of an ASHP, I thought this also typically required replacing radiators with larger ones, or switching to underfloor heating, due to the lower supply temp ? So the cost of the ASHP itself is only the start of it.
The issue with GSHP and ASHP is that the temperature differential of the radiators:rooms in that setup is not that great. Instead of piping a small amount of really hot* water around your house, you pump a much greater amount of slightly warm water to achieve the same heating. The trouble is, if your house pipework is made for a recent-ish efficient combi boiler, the pipes are likely to be a small gauge and can't achieve the flow rate needed to warm the house. So in some circumstances you'd have to replace all the pipework.
I thought this was a problem with newer houses, not old ones. Of course, insulation is another issue.
IANA central heating engineer, I'm just parroting something I heard on Radio 4.
(*piping hot??)
For you description lovewookie, I expect the energy demand of your house is too much to make an ASHP economically viable.
So in some circumstances you’d have to replace all the pipework.
interesting, the grants and associated quotes from local ish folk who've had it done includes new radiators, but maybe not new connecting pipework.
For you description lovewookie, I expect the energy demand of your house is too much to make an ASHP economically viable.
I think you're right.
what other alternatives are there for a flat roof, tiny back garden cottage in a conservation area?
I suspect, not a lot.
Lots of constraints there by the sound of it. More insulation, draft proofing and MVHR would probably be on my list if possible.
The problem with old houses is that energy flux through the structure was part of the equation for keeping moisture at bay and preventing the materials of the building from breaking down.
This is pretty much at odds with modern energy efficiency thinking.