Ok I've worked it out myself. I was inventing a magic free energy machine. I was thinking a cop of 4 would be able to extract 4 units of energy to the heat exc

Ok I've worked it out myself. I was inventing a magic free energy machine. I was thinking a cop of 4 would be able to extract 4 units of energy to the heat exchangers 1. But there's only 1 unit of energy in it to extract, which the heat exchanger is already extracting basically for free.