Comment by icehawk
20 hours ago
> So cooling a living space is always more costly than heating a living space. Simply because all the waste energy created by people living in the space reduces the total heating requirement of the space, but equally increases the cooling requirement of that same space.
This simply is not true for a furnace or electric resistive heat.
My furnace produces 0.9W of heat for every 1W of energy input. More efficient ones do 0.98, the best you get with electric resistive heat is 1W.
On the other hand my air conditioner moves 3.5W of heat outside for every 1W of energy input.
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.
5 replies →
> My furnace produces 0.9W of heat for every 1W of energy input.
I assume you mean that 10% of the energy immediately escapes your house?
Yes, last 10% goes up the chimney, so only 0.9W goes into the house.