russ_watters
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With an electric car, the heater is a 100% efficient electric coil. On a car with an internal combustion engine, the car is heated with waste heat, so there is no relevant measure of efficiency. You might say, though, that a 100W fan (estimate) can give you 4 kW of heating, or a COP of 40:1 (kinda like 4,000% efficiency).BobG said:How are you heating the incoming air? How efficient is your heater?
Getting rid of the excess heat is done with a fan and that fan doesn't use much energy. There is much more energy rejected by the fan/radiator than is input into the fan.In fact, how efficient is the motor driving the car and how are you getting rid of excess heat? I really don't know how efficient the electric motors used on vehicles are, but, generally, finding a way to dispel excess heat is a bigger problem than generating it.
It's a bigger load for a gas powered car because the energy for heating is free. For an electric car, the energy for heating comes out of the battery. In general, though:I think air conditioning is going to be a bigger electrical load than heating.
-An electric heater gives you 1 kW of heating for every 1 kW of input power.
-An electricity powered air conditioner gives you 2.3 kW of cooling for every 1 kW of input power.
Now for an air condiitoner, that's highly dependent on the conditions: run an air conditioner out of it's ideal operating range and you decrease it's efficiency substantially.