For a heat pump dumping heat a couple C above ambient (typical of heat pumps which is why people coming from furnaces complain that the air coming out isnt hot) that’s
n = 1 - 298/300 = 1-0.9933 = 0.67%
That means you’d need a machine that is more than 99.33% efficient to get any work out of that heat difference. For comparison, an engine losses 15-30% of energy just from the friction of polished metal cylinders and cams gliding close to another polished metal wall with a layer of oil in-between. The metal isn’t even touching.
Blue_Morpho@lemmy.world 4 hours ago
Carnot is 1 - T(coldside)/T(hotside) in Kelvin.
For a heat pump dumping heat a couple C above ambient (typical of heat pumps which is why people coming from furnaces complain that the air coming out isnt hot) that’s n = 1 - 298/300 = 1-0.9933 = 0.67%
That means you’d need a machine that is more than 99.33% efficient to get any work out of that heat difference. For comparison, an engine losses 15-30% of energy just from the friction of polished metal cylinders and cams gliding close to another polished metal wall with a layer of oil in-between. The metal isn’t even touching.