Sizing your ASHP
Run a smaller ASHP harder or a larger ASHP more gently for a given heating requirement?
I've opted to do the latter, oversize so that I have spare capacity and so the heat pump only really has to tick over. Just wondering what others have done or plan to do?
That might make sense if you look at fuel costs only, but if you factor in the additional running and captial cost of having BOTH technologies does it still stack up. Very simplified example.
100% gas:
boiler cost £600, installation £1,000
annual fuel cost £600
annual service £50
20 year total £14,600
100% ASHP:
pump £2,000, installation £2,000 (includes hard-standing and piping for external unit)
annual fuel cost £550
annual service £50
