From:  alan_m <junk@admac.myzen.co.uk>
Date:  28 Oct 2024 00:19:23 Hong Kong Time
Newsgroup:  news.alt119.net/uk.d-i-y
Subject:  

Re: heat pumps anyone ?

NNTP-Posting-Host:  null

On 27/10/2024 13:40, Theo wrote:
> alan_m  wrote:

> Agreed, but the SCOP gives you an idea of how much it'll cost over the year
> - in some kind of standard UK conditions.  If you are somewhere very
> non-standard (on top of a Scottish mountain or the Isles of Scilly) then
> it'll be different, and for that we'd need the full data.

I'm not sure over how many months the SCOP figure is calculated but the 
figure would be very misleading if months outside the real heating 
season were included. Including the summer months would push the SCOP 
figure higher.

Even within the geographical range of Cornwall to the lowlands of 
Scotland the difference in average weather conditions (temperature) 
would make the economics of an ASHP very different. With a reference 
location and all manufactures using the same regional figures the SCOP 
gives a comparison between models.

We are being told with the climate catastrophe we can expect many more 
periods of extreme weather, many more beasts from the East!  No use 
designing for the average weather if the system doesn't work or it 
cripples you financially when the COP figures approach unity  :)
Having the COP figures rather than SCOP means that you can establish if 
a ASHP is financially sensible for you.

>> It's a 6KW ASHP typic ally costing around £11K including installation and
>> controls with £7.5k back in grants. The advertised free bit is if the
>> cost = grant.
> 
> So that's 3.5K after grant.  I was quoted more for a like for like oil
> boiler swap.

There seems to be some assumptions in the pricing that the householder 
has a suitable hot water tank and the rest of the system has been well 
maintained. The householder also has to supply valid Energy Performance 
Certificate.

I don't know what the cost would be if trying to swap a combi boiler 
with instant hot water with their ASHP.  Grants don't apply to hybrid 
systems.

On web sites promoting ASHP they indicate £11k is the very bottom end 
for higher temperature heat pump installations.



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