Assume I live in a location where at any time of day and any time of year, I need to heat my house. Assume further that I have a room with no windows. In this case, does it make sense for me to buy efficient light bulbs, considering that any inefficiency in converting electricity to visible light simply leads to more heat being added to the room, which in turn, results in less heat being output by the heater to maintain constant room temperature.
Although these are somewhat idealized conditions, I don't think they are too far off from being realistic. For example, say you live near the arctic circle, it might be smart not to have many windows due to heat loss, and it seems reasonable that in such a climate, heating will be required at all times of the day and year. Assuming I haven't missed something, it seems to me, somewhat unintuitively, that buying efficient light bulbs is not a logical thing to do. Is this the case?
Best Answer
Yes, it does make sense to buy efficient light bulbs in this case. Here is why:
Modern state-of-the-art heating systems use heat pumps to do the heating work. Rather than just "burning" the electricity in resistive heating elements to "make" heat, a heat pump uses electricity to move heat from the outside of the house to the inside- and any waste heat generated in this process is exhausted to the inside of the house along with the heat drawn from outside the house.
This process is inherently much more efficient than using $P=I^2R$ losses to furnish heat.