You wouldn’t want to heat your house with a toaster; still, electric space heaters do have merit.

Would you try to heat your house with a toaster? Probably not. Aside from having to push the button that lowers the bread every minute or so to heat the element, the cost of running a toaster for several hours would probably scare you off.

But, really, a toaster is basically the same as any electric heater on the market. A toaster runs at about 900 to 1,000 watts and produces 3,413 British thermal units (Btus) of heat for every kilowatt-hour used, the same as any other electric heater. It could warm a room, given enough time, and a whole passel of them could heat a house, just like a standard baseboard electric heating system. But you wouldn’t like your electric bill, unless you had a super-insulated house or an extremely low electric rate, neither of which apply to most of us.

We tried several electric space heaters in our offices. We bought them at Home Depot, but you can get them anywhere. They cost $12, $20 and $60. We also tried a wall-mount convection heater available through some electric cooperatives.

We plugged the heaters into something called the Kill A Watt EZ Power Meter to measure usage at the outlet. The Kill A Watt Meter records consumption by the kilowatt-hour and automatically calculates electrical expenses by the hour, day, week, month and entire year.

Theoretically, all the heaters should have used the same amount of electricity to heat the same space. However, variations in outside temperature and heat from inside sources like lights and computers had some impact on the results. Still, our less-than-scientific testing confirmed that electric space heaters don’t differ much in action. In a room where the central heating vents were blocked, the heaters used about the same amount of electricity over the same amount of time, keeping the room at a comfortable temperature.

Still, there was some variation in the comfort level. Heaters with a fan did a much better job of dispersing the heat throughout the room, providing faster comfort, while convection and radiant heaters without fans provided good localized heat but warmed the room slowly and for a longer time. In the end, all the electric heaters performed well. They heated a small space at a reasonable cost.

But they are not meant to heat large spaces over a long time. Units advertised to cut your heating bills are assumed to work only when they are used in a small area, while the main heating system to the rest of your house is turned way down or off. Straight resistance heating, which all electric space heating is, no matter the means of delivering the heat, is not the cheapest way to heat your house. Electric space heaters can reduce your heating fuel bill, but they also will raise your electric bill. Be careful how you use them.

Conclusion
All electric space heaters are pretty much the same in terms of operating cost. They provide 3,413 Btus of heat for each kilowatt-hour consumed. Some space heaters use heat lamps for the heat, others convey the heat in oil-filled tubes; still others use ceramic to moderate the flow of heat so it’s more evenly dispersed. No matter the purchase price, they cost about the same to operate.
– Mike Buda

The Kill A Watt EZ Power Meter, available from several online stores, including Amazon.com, for about $30, is useful for monitoring the power consumption of large and small appliances.