Division of Energy

fact sheet

Division of Energy

Director: Emily Wilbur

Heating cold areas of your home, noticeably increasing the warmth in one area, or to save energy are several reasons you might choose to use a space heater.

If you turn your central heating system down a few degrees and supplement the heat in a small area with a space heater, you will probably save money. If you do not turn the thermostat down and add more heat with the electric space heater, you will increase your total bill.

Get the Right Space Heater for Your Needs

Electric, gas or wood heating appliances can be used for space heating. However, the most common form of space heater is electric because it is portable and convenient. Electric resistance heaters are the most expensive form of heating so consider other forms of space heating for more permanent situations. Below is a list of different types of electric space heaters that are especially suited to specific situations.

For spot heating, a radiant heater will warm objects or people in its path. They provide warmth almost instantly to objects, but they heat a room slowly. Examples of usage for this type of heater would be for a person at a workbench, in a chair or at a sewing machine. This type of heater gets hot enough to cause a fire or severe burn.

For constant usage, a radiator-type heater provides even warmth and a safe source of heat for limited areas. A good application would be any room in constant use that you want to maintain slightly warmer than the rest of the house. This type of heater would not be a good choice for quick warm-ups. The surface of this type of heater is not as hot as other types of heaters. With proper use, it should be safer with respect to causing burns or fires.

For heating an area quickly, a convection heater with a ribbon or wire heating element is best. A fan will help move the heat away from the heat source. Uses for these heaters would be in bathrooms, workshops and seldom-used areas. This type of heater gets hot enough to cause a fire or severe burn.

Cost to Operate

The cost to operate a space heater will vary depending on the type of space heater you use and the room you are heating. A good general formula for calculating cost is Kilowatts x Rate x Time = Cost.

Kilowatts - Setting the heater will run on. (Divide watts by 1,000 to get Kilowatts per hour.)
Rate - The cost of electricity per kilowatt hour. This can be determined for your area by contacting your utility company.
Time - Amount of time you will be running the heater.
For example, a 1,500 watt space heater running for 10 hours at a rate of $.10 per kilowatt hour will cost $1.50.

Kilowats x Rate x Time = Cost
(1,500w/1,000) x .10 kWh x 10 hours = $1.50


All electric resistance heaters are considered 100% efficient because there is no heat loss through ducts or combustion. Remember that some space heaters deliver heat more quickly or more concentrated than others. Also, using electric resistant heat to heat the entire house is generally more expensive than using other systems like a natural gas furnace or a heat pump.


  • Contact with the heating element in an electric heater can cause fabric to catch fire or can burn the skin. Install fire detectors in the rooms where space heaters will be used.
  • Space heaters can overload your electrical circuits. If a fuse blows or breaker trips, you have overloaded that circuit and need to contact your electrician.
  • Never use an electric heater with a common household extension cord.
  • Never operate a gas space heater in a room that does not have a working carbon monoxide alarm.
  • Energy-Savings Measures
  • Before investing in a space heater, here are a few energy-saving measures. Weatherizing your home by installing caulking and weatherstripping around doors and windows will help to eliminate air leaks. Also, clean or replace your furnace air filter on a regular schedule.

Questions to Consider

  • Does the space heater have a thermostat? In what area of the house do you plan to use the space heater?
  • Is the space heater safe for the area in your house in which you plan to use it?
  • What are the safety features of the space heater?
  • Some heaters have fans. Will the noise bother you?

Other Sources of Information

U.S. Dept. of Energy, Energy Efficiency and Renewable Energy Network
A service provided through the U.S. Dept. of Energy, the Energy Efficiency and Renewable Energy Network is a clearinghouse for energy efficiency and renewable energy information.

U.S. Dept. of Energy, Energy Savers guide to energy Efficiency and Renewable Energy

Saving Energy with Electric Resistance Heating

Nothing in this document may be used to implement any enforcement action or levy any penalty unless promulgated by rule under chapter 536 or authorized by statute.

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