ASHP, Just an outdoor fridge ?

[ReedRichards]

If you take the volume of the inside of your house and divide by the volume of the inside of your fridge then multiply that by the cost of your fridge to make a volume to volume comparison then the question might become "Why are heat pumps so cheap?"

[Radian]

27 minutes ago, ReedRichards said:

If you take the volume of the inside of your house and divide by the volume of the inside of your fridge then multiply that by the cost of your fridge to make a volume to volume comparison then the question might become "Why are heat pumps so cheap?"

 

At first blush yes, but you would be multiplying engineering overheads unnecessarily. Like the size of the fridge enclosure, when scaled to envelope an entire house for instance. So no, not a valid argument really.

[JohnMo]

3 hours ago, ReedRichards said:

If you take the volume of the inside of your house and divide by the volume of the inside of your fridge then multiply that by the cost of your fridge to make a volume to volume comparison then the question might become "Why are heat pumps so cheap?"

Would you then include for a fair comparison, the enclosure ie the house shell and the insulation, the finished linings etc. - then you are back to why are heat pumps so expensive?

[SteamyTea]

With regards to cost, surely we need to look at the unit energy prices.

My fridge takes, on average, about 12 W, so 105 kWh a year.

The temp difference is about 15K.

Surface area about 2.5 m².

So each m² is allowing 42 kWh/m² though. At a cost of £100, and so far 6 years trouble free service, that is £6.66/m².

Now my house with a wall of U-Value 1.5, and the same ∆T of 15 K, takes  about 2 MWh of energy to heat a year, so spreading that over the whole year, and the 100 m² of heat loss area. That works out at 20 kWh/m².

So roughly half the performance of my fridge needed.

So the price for an ASHP should be somewhere around £3.33/m².  £2000 for the unit only, if it lasts 6 years.

 

Seems the price is comparable.

 

(I am sitting in a cafe, so my numbers may be bollocks, lots of 'summer distractions')

 

Edited July 29, 2022 by SteamyTea

[joe90]

Economy of scale!, when ASHPs are produced in large numbers like gas boilers then the price will come down, same as anything  IMO.

[SteamyTea]

37 minutes ago, joe90 said:

when ASHPs are produced in large numbers like gas boilers

Refrigerant gas compressors, the major component of a heat pump, probably are made in larger numbers than gas boilers.

Both our main cars have them, though mine does make some strange noises sometimes.

Edited July 29, 2022 by SteamyTea