I many applications, efficiency is measured in terms of how much of the input energy is wasted generating heat instead of the actual type of energy you want. For example, lightbulbs generating heat instead of just visible light, or an engine generating heat instead of only kinetic energy.
But what about heaters? Would choosing a heater with a fan, blowing air around the room (so that the hot air doesn't just rise straight up to the ceiling) have any difference in the heat output of the device? Given that the heater with the fan would take some of the energy from its heating element to power the fan instead, so that the devices still use the same number of watts. Thermal energy is just kinetic energy, but with motion in many different directions at once, right? So kinetic energy should be a special form of thermal energy? And thus, all heaters should be exactly as efficient, nomatter what nice features they have (such as a fan)?
Are all heaters (same wattage, electric to thermal, no geothermal or other extra energy source) exactly as efficient as each other?