Heatmax's fan coil, which is the indoor unit of an air conditioning system, transfers heat or cooling to the space by supplying it with water at the appropriate temperature. In Greek, it is referred to as a forced air circulation body. Its operation is based on forced air circulation created by the built-in fan.

With the help of the fan, heat is distributed throughout the space, unlike simple radiators where heat distribution occurs naturally through convection. It can be connected to a heat pump or boiler to provide heating and cooling year-round.

The unit is installed on the ceiling of the space, integrated into a false ceiling or free-standing, depending on preferences. Air exhaust occurs only from the point where the unit is installed, unlike ducted air conditioning units where multiple air exhaust points can be positioned.