A convection heater is a heater which operates by air convection currents circulating through the body of the appliance, and across its heating element. This heats up the air, causing it to increase in volume and so become buoyant and rise. Oil heaters are an example for this kind of heating appliances.
A convection heater may have either an electrical heater element, hot water coil, or steam coil. Because of the natural ventilation, they are quieter in operation than fan heaters.
However, recent advances in fan motor technology, have reduced the noise levels in fans considerably, some operating as low as 25 decibels (almost inaudible to the human ear) therefore fans can be added to the construction of domestic and commercial convected heat exchangers, which now makes fan assisted convection heat emitters a viable option in heating systems even in bedrooms.
Further more, this combination works extremely well in conjunction with renewable technologies e.g. (Ground source heat pumps air source heat pumps), that operate at lower temperatures, convection heat exchanger and fans, can offer up to 300% more output than standard radiant panels at low temperatures.