Fan heaters (or electric convective fan heaters, depending on where you're from) are cheap to buy but can be very expensive to run, especially over long periods of time or when used to heat large areas. These types of heaters are commonly take one of two different shapes – tall and slender, and short and flat. If you're choosing between the two, the tall and slender version is normally better, because it circulates more air faster.
How do electric fan heaters work?
Electric fan heaters work by running a current through a resistive heating coil, which converts electric energy into heat energy. Air is then drawn in over this resistive heating coil using a fan where it's rapidly warmed and propelled out into the room. Because of the way they work, electric fan heaters also dry out the air and can circulate dust, which in turn can cause dry eyes and sore throats, or create problems for those with allergies or respiratory issues.
Electric fan heaters normally feature a thermostat which allows you to control the amount of heat being produced, and often also feature speed controls for the fan. Most of portable fan heaters also double as regular portable fans, simply deactivating the heating element when it's not needed.
Where can they be used?
Because they're convection heaters and they circulate warm air, fan heaters are effective for heating small rooms like bedrooms and studies. They can be used in all kinds of places, but because they're portable electric appliances, they shouldn't be used near or around sources of water. Ideally, these fans should sit on the ground. The warm air they produce inevitably rises, so placing them on the ground will help to ensure that the room is warmed more evenly.
These types of heaters should never be covered - doing so can very quickly turn them into a fire hazard.
How energy efficient are electric fan heaters?
Electric fan heaters are extremely inefficient, and compared to most other types of heaters, they're very expensive to run - which is a shame when you consider how cheap they are to buy! Electricity itself is a very inefficient fuel source in terms of the CO2 emissions associated with its production. A single electric fan heater can consume more than three times as much electricity as a 4 to 6 star reverse cycle air conditioner heater though, making it one of the most inefficient heating options available.