Plain Talk About Electric Space Heaters
“Space heater” is a term used to describe basically any type of heater used to warm a defined space. The variety of types can be confusing when trying to determine which to buy for a particular application. This article will describe in basic terms some of the many types of electric space heater, and some advantages and disadvantages of each.
Several types of electric space heater are available today, but they fall into two basic categories: radiant and convective. Basically, radiant heaters work like the sun. They send heat to objects, such as people, but don’t heat the air. Objects between the radiant heat source and a person will greatly reduce their effectiveness (this is why it’s cooler in the shade!). Distance is also a problem, since the warming effects diminish as distance increases. A radiant heater will warm things quickly, but probably is not as good for prolonged regular use or whole-room heating.
In contrast, convection heaters warm the air around them. Warmed air rises and pushes cooler air down, setting up a circulation and bringing cooler air down to the heater to be warmed. These heaters provide more stable and widespread warmth and are better for ongoing use.
Many older convection heaters used metal coils that got very hot, creating a potential fire hazard and prompting warnings about putting them near anything flammable. It’s still a good idea to follow recommended safety precautions, but most recent models are much less risky.
Modern ceramic space heaters use a ceramic element to warm aluminum elements, which warm the air. These don’t get nearly as hot, and the covers on many models stay cool to the touch. Most ceramic models also propel warmed air into the room with a fan, improving circulation and heating the room quicker and more evenly, especially if the fan oscillates. Noisy fans are perhaps the biggest downside to ceramic heaters.
Panel Heaters warm a room by convection also, but silently, since they do not use fans. They warm faster than oil-filled heaters. Some can even be wall mounted, saving floor space.
Oil-filled heaters are also silent, and are styled like old radiators. The ‘fins’ increase the surface area exposed to air, which helps them warm efficiently. They are usually sealed, so there is no need to refill them. Oil filled heaters also work by convection, but slower than either ceramic or panel heaters, since the liquid must warm up first. But the liquid doesn’t lose its heat very fast, so unlike other heaters, they continue to give off warmth even when they cycle off. Therefore they efficiently provide steady warmth. Newer models also do not get as hot to the touch as older radiators, so the risk of burns or fires is not as great.
Regardless of type, most modern heaters are thermostatically controlled, functioning much like the thermostat on a central system. Set the desired temperature, and the unit warms the air to that temperature, then cycles off. When the temperature gets a few degrees lower, the space heater cycles on again. Users need to be willing to adjust to comfort, because the thermostat is located on the unit where the air is likely to be warmest.
Other common safety features include tipover switches, which automatically cut the unit off if it is tipped, overheat protection, and auto-timer shutoffs. Common to all electric heaters is that they should be plugged directly into a wall outlet, avoiding the fire risk associated with extension cords.