Comment by EVa5I7bHFq9mnYK
18 hours ago
My AC works in both directions, in winter it moves more cold outside than the power it consumes. Not sure what the factor is exactly, but I think same as for cooling.
18 hours ago
My AC works in both directions, in winter it moves more cold outside than the power it consumes. Not sure what the factor is exactly, but I think same as for cooling.
Thermodynamics unfortunately disagree. As your temperature deltas get smaller efficiency goes down.
"Thermodynamics" is singular :) As for the numbers, my AC's manual shows COP of 3.71 for heating and 3.13 for cooling.
So you are spot on, in winter temperature deltas are larger, and efficiency goes up.
Those high COPs are probably for relatively small temperature deltas. Heat pumps get _less_ efficient when the temperature deltas are larger. See page 18 of the manual linked below for an example. As the temperature gets lower, the heating COP gets lower. The same should be the case with cooling (higher outdoor temperatures lead to lower COPs), but the data is not presented in the same way.
https://backend.daikincomfort.com/docs/default-source/produc...
3 replies →
> "Thermodynamics" is singular :)
> plural in form but singular or plural in construction
(https://www.merriam-webster.com/dictionary/thermodynamics)
I think American and British English treat words like this differently.