The transfer of energy in a surface cooling system is mostly done by radiant heat exchange, approximately 80%. The absorbing surface, a floor, wall or ceiling is cooled to a temperature lower than the items and occupants within a room. This cooled surface will then absorb radiant energy proportional to the temperature difference between the surface and the room contents.

In reducing the radiant temperature the occupants feel more comfortable even though the air temperature has only slightly changed. This effect is analogous to a church or cave where the walls and floor are at a lower temperature than the air making the space feel cooler.

Air conditioning works in a different way. Mechanically forcing air over cooling elements thereby cooling the air in the room but not significantly reducing the radiant temperature. This results in extremes of radiant and air temperature being created. The big difference between air and radiant temperature creates discomfort, experienced by anyone who sits near both a south facing window and an air-conditioning unit on a hot summer’s day.

Surface cooling works by reducing the radiant temperature more than the air temperature. The air and radiant temperatures are closer together which, with the absence of noise and air movement, makes for a more comfortable working environment.

Any surface can be used to cool, an underfloor heating system with the appropriate controls can be used as a floor cooling system however performance is increased when the system is installed into a ceiling.

Surface cooling is able to provide comfort cooling to most commercial applications with outputs up to 70W/m² for a ceiling system and 50 W/m² for a floor system.

A surface cooling system will reduce the sensible loads in a space. It may be necessary, in humid conditions, to provide dehumidification. Dehumidifying a space also has the benefit of reducing the dew point (which limits surface temperature and output) and increasing the cooling capability of the system.