Applications of radiant floor cooling systems

The use of floor heating has been know sincemore than 3000 years from the Chinese Kang,the Korean Ondol, the Romans hypocaust to daysmodern water based systems embedded in thefloor construction. The application of suchsystems also for cooling is however less known.To evaluate the usefulness of radiant floorcooling it is important to take into accountcomfort, cooling capacity, control and design.One limiting factor is the floor surfacetemperature. In spaces with seated or people thefloor temperature should not be lower than 20 Cfor comfort reasons. For higher activity levels alower floor surface temperature may beacceptable and the limitation will then be thedew point temperature in the space. The heatexchange coefficient between a cooled floor andthe room is typically around 7 W/m2 C where5.5 W/m2 C is radiant heat transfer. In spaceswith mainly seated occupants the upper comfortlimit for the operative temperature in summer is26 C. This means that based on the heatexchange between the floor surface and the rooma maximum cooling capacity for a floor system is40-50 W/m2. In several spaces like atrium,entrance hall or other spaces with windowfacades there will often be a lot of directsunshine on the floor. In these cases the coolingcapacity is significant higher and may reach 100-150 W/m2. The influence of these parameters isdiscussed in the paper and several applicationsare presented.