Vendors of heat pump
s and other space heater
alternative soften engage in false advertising.
We've all seen ads proclaiming heat pumps as "more efficient than space heaters" this is simply not true. Heat pumps are more economical
. A space heater operates at 100% efficiency, greater than that is impossible. In any system, the energy (heat) in must
equal the energy out. A low resistance wire simply draw a large electrical current. Power
. Since a wire does no other work, such as a motor would, all the energy is emmited in heat. Therefore, a heater drawing 5 amp
s on a 120 wall voltage line, is giving off 600 joule
s in heat per second (at 100% efficiency).
Heat pumps use the wonders of technology
(I don't know about their inner workings) to transfer heat from an outside enviroment into your house. The operating power (the power it is drawing from the electric grid) is less than the heat gain, but the total energy in still equal
s the total energy out. The end result being heat pumps provide more heat per dollar than space heaters.