3 ms·

I believe that for every joule of electricity used, 4 or 4.1 joules are pumped from the environment into the water. This is contrast to conventional water heat

I believe that for every joule of electricity used, 4 or 4.1 joules are pumped from the environment into the water. This is contrast to conventional water heaters which are bounded by an efficiency of 1, where, for example, burning gas directly heats the water with some heat leaking into the environment instead of the water.

rsynnott 22d ago
For a _gas_ heater, 1 would actually be unrealistically good. Conventional gas boilers tend to be about 70% efficient. Condenser boilers can do better, up to about 90%, but in practice performance is highly dependent on temperature of returning water.