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fan heater is a heater that works by using a fan to pass air over a heat source (e.g. a heating element). This heats up the air, which then leaves the heater, warming up the surrounding room. They can heat an enclosed space such as a room faster than a heater without fan, but, like any fan, create audible noise.
Electric fan heaters can be less expensive to buy than other heaters due to simple construction. The fan carries heat away from the device, which can be made smaller without overheating. The relatively small amount of electricity used to operate the fan is partly converted to additional heat, so that efficiency is not a problem. All heaters without external ventilation are nearly 100% efficient, meaning that almost all energy input goes into the room as heat. However, if the efficiency of generating the electricity is taken into account, the overall efficiency decreases significantly.
Electric fan heaters are more expensive to run than fuel powered heaters due to the cost of electricity. This makes them best suited to occasional use rather than as regularly used heat sources.
Externally vented non-electrical (combustion powered) fan heaters lose some heat to the outdoors, and are thus less efficient. These are used where it is necessary not to release the fumes of combustion into the heated area.
Electric fan heaters are unsealed appliances with live electric parts inside, so they are not safe to use in wet environments due to risk of electrocution due to the potential of moisture providing conductive paths to electrically live parts. Electric fan heaters usually have a thermal fuse close to the heating element(s) to protect against overheating due to fan failure, and a tip-over switch to shut it off when the fan outlet is not in the desired as-designed orientation. Metal-cased heaters perform better in potential fire-causing faults than plastic-cased ones, since the case will stay intact and is not flammable, but they present a higher risk of electrocution during heater malfunctions.
Portable fuel-powered fan heaters release all the fumes of combustion into the room, creating a risk of poisoning by carbon monoxide and carbon dioxide. Most installed fuel fan heaters in the first world use a heat exchanger and external ventilation, avoiding this risk, and dumping the combustion gases outdoors.
The next picture shows the two overheat cutouts. The bimetal cutout (left) operates if the device overheats because the intake is blocked or the fan fails, and resets once the heater cools after the obstruction is removed. The thermal fuse (right) is a failsafe backup device that will disconnect the heating element permanently in case of extreme overheating causing risk of fire, usually because the bimetal switch fails to operate.
Industrial
fan heaters use high-output finned heating elements in front of a fan to provide a larger airflow and higher kilowatt rating than many smaller residential fan heaters. Industrial fan heaters can be used in warehouses, shipping containers, clean rooms, shops and other general purpose heating applications. They can also be used as dryers or dehumidifiers with modified attachments or mountings. Portable industrial fan heaters tend to range from around 1.5 kW up to about 45 kW with either axial or centrifugal fans and various staged controls and over-temperature safety limit controls.
