Legacy propane infrared plaque heaters work by using a ceramic plaque that emits infrared radiation to heat people and objects directly in the path of the beam. Combustion of the propane in the heater heats the plaque to a high temperature, causing it to radiate infrared energy.
The primary advantage of using Legacy propane infrared plaque heaters is that the infrared radiation is directed to the area in need of heat. This area can be some distance from the heater itself, in contrast to attempting to heat an area with open flame or heated air. Since the ceramic plaque is heated and not the air in the room, more of the energy contained in the propane fuel is transferred from the heater. In addition, air molecules are less absorbent of infrared radiation than people, so anyone in the area to be heated receives more heat more quickly than with other heating methods. Propane plaque heaters do not require electricity to run, so they are useful in places where power is unavailable or unreliable.
The primary drawback of propane infrared plaque heaters is the need to vent the propane combustion products safely from the area of use. It is unsafe to use a propane plaque heater in an area with poor ventilation, as dangerous levels of carbon monoxide and other gases can accumulate and cause death or injury.