How to Buy a Space Heater

Portable heaters (or space heaters) are heating units that are used to supplement a central heating system. For example, they can be used to efficiently heat one room while keeping others cool. Or, they can be used to compensate for poor central heating designs (e.g. many town homes are tall and thin with inadequate gas-forced air systems - resulting in hot top floors and cold basements.)

Shown above, Q Mark coil heater (left), Bionair ceramic heater (center), and Delonghi oil-filled heater (right)


  • Wire Coil Heaters - similar to a toaster oven, wires or ribbons are coiled around a metal frame or porcelain insulator
  • Radiant Heater - use a quartz or infrared element to directly heat the object in front of them.
  • Ceramic Heaters - small units with ceramic disk heating elements. They are typically safer than other types of heaters because the produce a level of heat that is below the temperature needed to ignite paper.
  • Liquid-Filled Heaters - usually larger units that resemble small radiators. They heat up slowly, typically don’t have fans. But they are energy efficient, make little noise and are safer than wire coil models


  • Thermostat - Most units have thermostats to turn off the heating elements once a specific temperature has been reached.
  • Fan - some models have fans to force air over the heating elements, while others rely on air flow created by the heat itself.
  • Safety Switch - Some higher-end heaters have an internal switch that turns the unit off if has been knocked over.

How to Choose

First determine the type of portable heater that is best for your specific needs:

  • If the area you are heating is large, consider a fan-forced unit.
  • For smaller spaces, or for quiet operations, consider liquid filled models
  • For small spaces where you’ll be moving the heater around, consider a ceramic model

Next determine the size of space heater you need:

  • 2,500 BTUs should be sufficient for a poorly heated room 100 sq. ft.
  • 5,000 BTUs should handle a 1,000 sq. ft. room

Note: Heating capacity is measured in BTUs (British Thermal Units). A unit with an output of 3,400 BTUs will consume 1,000 watts per hour.

Finally choose a specific model:

  • Examine the grill over the heating element, does it look sturdy?
  • Look for a unit that has been tested and certified by a nationally recognized testing laboratory (e.g. UL)

Safe Use

  1. Hook-up - Electric heaters should be plugged directly into wall outlets, if an extension cord is necessary, us a heavy gauge, e.g. one with 12 or 14 gauge wire. Feel the extension cord after prolonged use, if the cord is hot, you may need a more heavy duty cord.
  2. Never use a space heater in a wet area such as a kitchen or bathrooms unless the unit is specifically designed for that use.
  3. Read and follow all warnings in the user manual