Effectiveness of electric resistance space heaters
Electric resistance heaters are 100% efficient. This statement is true but also somewhat confusing. The efficiency of turning electricity into heat is indeed 100% efficient. Often when systems have efficiencies <100% it is because there is some heat generated as an un-intentional byproduct. An electric motor in an EV for example might be 85% efficient, which means that 85% of the electric energy consumed by the motor is moving the car, the other 15% is heat. Since our electric resistance space heaters are only trying to make heat, they are 100% efficient. Heat pumps on the other hand can be 300-400% efficient, because they use electricity to transfer heat from outside to inside your home. This efficiency is also called the Coefficient of Performance (COP). Another way to think about the performance of an electric resistance space heater is to look at how effective it is in warming up a room or a person. UC Berkeley's Center for the Build Environment has done decades of research...
