Points out that the floor surface temperature in spaces with seated or standing people should not be lower than 19degC (66degF) for comfort reasons. For higher activity levels a lower floor surface temperature my be acceptable and the limitation will then be the dewpoint temperature in the space. The heat exchange coefficient between a cooled floor and the room is typically round 7W/m.degC (1.23 Btu/ft2.h.degF), where 5.5W/m2.degC (0.97Btu/ft2.h.degF) is radiant heat transfer. In spaces with mostly seated occupants the upper comfort level for the operative temperature in summer is 26degC (79degF). This means that, based on the heat exchange between the floor surface and the room, a maximum cooling capacity for a floor system is about 50W/m2 (16Btu/h.ft2). In spaces such as atria, halls or other spaces with window facades there will often a lot of direct sunshine on the floor, in which case the cooling capacity may reach 100 to 150W/m2 (32s to 47Btu/h.ft2). Notes that the cooling capacity also depends on the floor construction, distance between tubes, water flow rate and floor covering. Discusses the influence of these parameters and presents a sizing method based on a European standard.

KEYWORDS: year 1997, Floors, floor cooling, radiant cooling, sizing, performance