So did engineers since decades. Just the fact that you get efficiency ratings of more than one in terms of primary energy input to heat energy provided should always have been a massive selling argument. If planned well you can get yearly averages of 400-500% energy output vs energy input.
Heat pump was one of the inventions I thought of in my childhood and was like “oh, it actually works and is good” as an adult.
Of course, the child version was along the lines of “what if we take fridge, put the cold end out and hot end in”, but you see the point.
So did engineers since decades. Just the fact that you get efficiency ratings of more than one in terms of primary energy input to heat energy provided should always have been a massive selling argument. If planned well you can get yearly averages of 400-500% energy output vs energy input.