Portable Space Heaters

Small portable space heaters can help reduce winter heating bills when properly used to supplement your main heating system. They can be useful in mild weather for heating one room without turning on your main heating system. In rooms that don't seem to get enough heat, or in rooms used by individuals sensitive to cold, portable space heaters can provide extra heat without overheating the entire house.

Portable space heaters typically have heating capacities between 10,000 and 40,000 Btu per hour, and can be fueled by electricity, propane, natural gas, or kerosene.

Most space heaters heat by convection, or circulating air. Some are equipped with built-in fans while others rely on natural convection to distribute the heat throughout the room. Others use radiant heating that heats people and objects, not the air. These units must be located such that occupants are in direct line of sight from the heater. Because they don't heat the entire room, they can be more efficient, particularly in rooms used only for short periods of time.

Electric Space Heaters

Electric space heaters are usually more expensive to operate than combustion space heaters, but because there are no combustion byproducts, they can be safely used with no venting. However, they can still cause burns and fires if not used properly.

One popular type of electric space heater contains a heat transfer liquid that is heated by the electric element. The fluid stores the heat, releasing it slowly and allowing the heater to cycle less frequently and provide more even and comfortable heating.

Combustion Space Heaters

Combustion space heaters are classified as either vented or unvented, or "vent free." Unvented combustion space heaters should not be used inside your home, as they can produce potentially hazardous byproducts including nitrogen oxides, water vapor and in some cases carbon monoxide. They can also deplete the oxygen in the room where they are located.

Vented units are permanently installed on or next to an exterior wall, so that the combustion byproducts can be vented to the outside. The most efficient models use sealed combustion with a duct to bring outside air into the combustion chamber. Sealed combustion heaters are also safer to operate, as they are less likely to backdraft and allow the combustion byproducts to enter the living space.

Space Heater Safety

Safety should be a primary concern when using any type of space heater. The Consumer Product Safety Commission estimates that more than 25,000 residential fires every year are associated with the use of space heaters, causing more than 300 deaths.

When buying and using any portable space heater, always follow these safety guidelines:

  • Make sure the heater bears the Underwriter's Laboratory (UL) label
  • Choose one that is thermostatically controlled to avoid overheating
  • Select the correct size for the room being heated
  • Locate the heater on a level surface away from foot traffic
  • Be careful to keep children and pets away from the heater
  • Never leave space heaters operating unattended or while sleeping

For combustion space heaters, in addition to the manufacturer's instructions, be sure to follow these general safety guidelines:

  • For liquid-fueled heaters, use only the approved fuel and follow the manufacturer's fueling instructions - never use gasoline
  • Never fill a heater that is still hot, as it can cause a fire
  • Store liquid heating fuels outside in approved containers
  • Have vented space heaters professionally inspected every year - if the heater is not vented properly or if the vent is blocked, carbon monoxide can enter the home
  • Make sure the heater is properly set up and adjusted for the type of gas used (natural gas or propane)

There are also safety guidelines specific to electric space heaters:

  • Look for a unit with a tip-over safety switch, which automatically shuts off the heater if the unit is tipped over
  • For radiant type heaters, look for one with a guard around the heating element to prevent people or objects from touching the hot element
  • Avoid using lightweight extension cords, as they can overheat and cause a fire - if an extension cord is necessary, use a heavy-duty cord of 14-gauge wire or larger
  • Never run the heater's cord under rugs or carpeting
  • To prevent electrical shocks, always keep portable electric heaters away from water and never touch an electric heater if you are wet

Related Topics: