Heat the Bed or Heat the Room: The Energy Arithmetic of an Electric Blanket Against Night-Time Space Heating

Faced with a cold bedroom, a household can heat the room or heat the bed, and the two strategies differ in energy use by a large factor. This paper computes both sides from stated assumptions: an electric blanket at 60 watts with a stated duty cycle of 0.55 uses 0.26 kilowatt-hours over an eight-hour night, while holding the bedroom three degrees warmer against a stated room heat-loss coefficient of 55 watts per kelvin uses 1.32 kilowatt-hours — 5.0 times as much — and heating a whole flat to the same end uses 16.4 times as much. Over a stated 120-night season at 0.30 dollars per kilowatt-hour, the blanket strategy costs 9.5 dollars against 47.52 dollars for the room, a saving of 38.02 dollars, on top of the bedding-insulation arithmetic that makes the cooler room comfortable in the first place. This study is simulated, not measured.