A convector is a heating surface that transfers heat mainly by convection. Convection is the process by which heat is transferred when cooler air flows over the warm surface of a solid material.

A convector consists of water-filled heating plates, fitted with corrugated fins, which create a very large overall surface area, thus increasing its ability to transfer heat to the air by convection. Over 90 % of a convector’s heat energy is transferred to the air by convection.

Convectors are often used in locations where there is not enough space for radiators. The amount of heat energy transferred by a convector will decrease if installed in locations where airflow is restricted. The heat transfer will decrease by approx. 20–25 % when installed in a recess, and by 15-20 % if located just below a ceiling.

When a convector is fitted under a ceiling, there is also a risk of a large temperature gradient in the room, as a layer of warm static air forms under the ceiling. Lack of heat at floor level may be uncomfortable for the feet or increase the chance of floor draughts.