Air source heating

No, but this might be helpful:

As was said above, no but this might be helpful

Thank you.

bill

Thank you.

Bill

Currently planning an ASHP to replace an oil boiler, done a lot of research. What did you want to know?

Theo

Having just had a read through that, I am rather suspicious of some of the claims.

I wonder if some of the claims are for areas of the world with a different climate and have just been "read across" to sell the products in the UK.

Yup, not clear...

Also no allowance for the capital costs considered.

The prices for energy they quoted also look unrealistic (they did have the ratio of lekky to gas price about right - but numbers that looked like they were a decade old - so that would have made the comparisons come out much "closer" than in reality).

They were also keen to compare against coal fired and resistive electric heating, but seemed to leave out comparisons to gas / oil.

(I would be surprised if there are that many places with coal fired CH in the UK!)

Even the assumption that "renewable" energy is low carbon is a bit of a stretch for the UK, where the best load factor for wind is under 50%, and under 25% for solar in the summer (4% in the winter!), so more the half the time the energy shortfall is being made up by fossil alternatives generally.

There's lots of stuff about heat pumps around that's about a decade old (including the report posted in this thread) - things have moved on, so they should be read with large pinches of salt.

Coal fires yes (listed old houses etc), but not centrally heated...

I did the numbers and a heat pump running from electricity generated by a CCGT still works out less CO2 per kwh heat than burning oil. It was a bit more than burning gas directly, although that depends somewhat on your COP.

Theo

A couple of houses round here have it. Well insulated and underfloor heating. Supplementary immersion heater for hot water.

Some have supplementary resistance heating for the house. A lot depends on what refrigerant gas they use.

It's all that will be available in the future. Be a trend setter!!

I have a wood fired stove.

That doesn't mean that it is the best heating system for an existing house nor does it mean that is the cheapest to run.

As most of the sites suggest it's ideal for underfloor heating when the house is much better insulated than the vast majorities of properties. But, with a better than average insulated property other forms of of heating may/will be cheaper (ignoring subsidies) than air sourced heat pumps.

The policy aim is for a reduction in CO2 not necessarily a reduction in the cost of heating your home.

Can't there be a primary heat pump to heat a tank of water, and a secondary one to take the heat from the tank and ramp it up to a high enough temperature for standard radiators and hot water for baths &c.?

Theo, have you found an up to date comparison between storage heaters and ASHP? The cost of installing and running and maintenance would need to be in it. I have a good friend who was looking at buying a 10K ASHP, which has a life expectancy of 10 years. This was his words. Newish build, underfloor heating. (First ASHP was off ebay)

Why would anyone install storage heaters - the worst of all worlds?

My reasoning was use a green energy supplier so that there was no CO2, so it is a level playing field. My boiler needs replacing soon and I briefly looked a GSHP, I have the land, but it did not look a goer.

Just a warning , there was some discussion here several months ago on AirSource specs .It did appear that the US and Europe have very different definitions for 1 of the key efficiency parameters.

Indeed. Low capital cost is all they offer. ASHP is half the running cost or less, but you really need UFH to use the low temperatures. And mega insulation to allow for low heat output.

Bless!

GSHP very good with UFH and well insulated house. Otherwise stick to fossil, it will be less CO2 anyway. Not that that is in nay way relevant to anything