Kerosene heaters, sometimes called paraffin heaters, are portable space-heating units that burn kerosene cleanly with an up to 99 percent efficiently. In fact, the only time they produce any noticeable fumes is during start-up and when you shut the unit down.
Kerosene heaters can be used to supplement heating in drafty rooms, heat remote cabins or act as emergency heating after a power outage. Many units have a battery-powered electric igniter, so they are easy to start. But unlike portable electric heaters that are adjustable, kerosene heaters basically have one setting: "high." The exception is industrial forced air units.
There are three basic types of kerosene heaters: radiant, convection and forced air. All basically use a circular fiberglass wick to move fuel from a tank to a burner unit known as a “catalytic converter.”
In convective kerosene heaters, the heat is radiated in all directions to heat the air, which then heats-up the room. These units are powerful - generally rated at 20,000 BTUs and up. Because the heat is radiated in all directions, convective heaters need to have at least a 3-foot clearance all around the unit from any combustible materials. They are normally placed in the middle of a room.
Because convective heaters are so powerful, you can actually heat a small house in very cold regions, though some parts of the house would get much warmer while other areas further away from the unit will be much colder. Nevertheless, these are the preferred heating units for remote cabins, garages and large workshops.
Radiant kerosene heaters have their burner unit encased in a glass cylinder. One side within the glass cylinder holds a polished stainless steel reflective surface. When the burner heats-up the infrared heat waves are reflected directly out the front side in one direction. Because the heat is projected in one direction, radiant kerosene heaters can safely be placed against a wall.
These units usually produce less than 10,000 BTUs, which makes them a good choice for heating individual rooms or small apartments. They also normally operate for up to 15 hours on 1 gallon on fuel, the normal size of the fuel tank.
In colder climates, multiple heating units in individual rooms work well not only for comfort, but because if one unit to cool down for refueling, the second unit would continue to produce heat.
Forced air kerosene heaters are used in large industrial spaces and use an electric fan to force heated air out one end of the unit, which requires an electric outlet. These large units, ranging from 125,000 BTUs to 215,000 BTUs, are mounted on wheels, have thermostat heat controls, fuel gauges and auto shut-off.
Because kerosene heaters vent their combustion products, nitrogen dioxide and carbon monoxide, into the indoor air, a window should be left cracked open. Kerosene heaters also produce very hot surfaces and can pose a fire risk so they should never be left unattended, even briefly. This is especially true while you’re sleeping.