From Peter Borrell
I accept that the Aircon advertisement Feedback mocks implies something astonishing by saying their products’ “heat pumps… generate more heat than they use” (3 March). In the context of the many barmy claims which Feedback frequently, and rightly, exposes, this one is just a bit too close to nit-picking for my taste.
Like refrigerators, heat pumps use electric power to transfer heat from somewhere cold to somewhere warmer – a practical manifestation of the second law of thermodynamics (heat can only be transferred from cold to hot with external work). So the heat coming out can indeed be much greater than the electrical energy supplied to the pump.
Practically, we would all be better off if those presently using electric heating were able to deploy heat pumps instead. Not only would our electricity demand decrease appreciably, but we would substantially diminish our output of carbon dioxide.
Newcastle-under-Lyme, Staffordshire, UK
