Thermal discomfort can occur near a glass curtain wall in winter because of increased radiant heat loss from the occupant to the cold wall. The discomfort from the decrease in mean radiant temperature caused by the cold surface can be compensated for by raising the local air, ceiling, or floor temperature. In a field test, all of the compensation methods worked, with the subjects preferring the radiant ceiling panel system. For radiant compensation, the location, size, and panel surface temperature are designed and adjusted to raise the local mean radiant and, thereby, the operative temperature of the occupied area to comfort levels. Such panels are best controlled by systems that sense both radiant and air temperature as used in the determination of operative temperature.

Paper from IAQ 1997 -- Design, Construction, and Operation of Healthy Buildings: Solutions to Global and Regional Concerns