How to Buy a Space Heater

Types of space heaters

There are two types of electric space heaters: radiant and convection. Here are the key differences:

Nearly all space heaters produce the same amount of heat. The differences lie in safety features, convenience features, reliability and the way the heat is directed. Convection heaters typically have a maximum setting of 1,500 watts -- usually with a lower 750-watt setting as well. This means that an electric heater can produce 5,100 British thermal units (Btu) of heat at the high setting and 2,550 Btu at the low setting. Experts estimate that providing heat on a very cold day to a well-insulated room with an 8-foot ceiling requires about 10 watts (or 34 Btu) per square foot of space. However, if your space heater is not the sole heat source, but a supplement to a central heating system, then 5 to 7 watts per square foot may be enough.

When buying and using an electric space heater, experts say to keep the following points in mind:

• Look for the Underwriters Laboratories (UL) seal. This indicates that the electrical-certification group has tested the model for possible safety problems.

• Avoid overloading circuits. If a heater plug or wire gets warm, this can be a sign of a problem with the wiring in the outlet or circuit.

• Opt for automatic shutoff. Automatic safety shutoffs include tip-over switches, overheat protection and touch sensors, which shut the heater off if the grill is touched. The Department of Energy says that a tip-over switch, in particular, is essential.

• Think about placement location. A heater should always be placed on a level surface out of the path of traffic. It is also best to plug a heater directly into the outlet and avoid using an extension cord. Make sure all combustible materials, such as curtains and bedding, are at least 3 feet from the front of the heater and well clear of the sides and back. Also, place your heater in such a way that its air intake is not blocked. Some flat-panel heaters can mount directly on a wall. Don't use an electric heater in a damp area, such as a bathroom or laundry room, unless it is designed for this purpose.

• Go for the extras, they can be convenient. Users say that timers, digital thermostats and remote controls are all very convenient features to have. Many owners who don't have these features say they wish their heater had them.

• Check the lights. Owners often report that LED lights on heater controls are bothersome at night, and some heaters have brighter display lights than others.