Convection Heaters
Convection heaters transfer heat by movement of air over a heated element, this can take various forms but is usually via a heat exchanger. Examples: Wall mounted panel heaters, oil column heaters.
First, a convection heater warms the cold air at the bottom of the heater where the heating element is. The warm air expands, becomes less dense and rises to the top of the room. When the air reaches the top of the room it is pushed sideways towards the far wall by the more recently warmed air rising from the heater below. In this way, warm air moves to the other side of the room. Once on the other side of the room the air drops down both because it has cooled a little and because the air behind it continues to push on it. The air then continues to circulate back to the heater and repeats the process. By continuing to circulate, the convection current transfer’s heat energy to the other side of the room then heats the entire room. Convection heaters work at there best when placed against a wall. However, an increased effectiveness is gained if the heater is against an external wall or under a window.