Radiant floors serve as a passive space conditioning system providing quiet, draft-free conditioning. Radiant systems also consume 20-30% less energy than forced air systems because water is approximately four times more efficient as a heat transfer medium than air, and fan energy is no longer required. For the Demonstrations Commons Building radiant floors will be used for both heating and cooling of the Commons Room, Den, Foyer, and Corridor spaces. Radiant cooling is an efficient tool for the dry California climate and allows the University to test a leading edge HVAC system. Each radiant zone will have a thermostat and humidity sensor and the chilled water temperature entering the radiant floor will be controlled to prevent condensation. Ventilation air will be provided by air-handling unit or natural ventilation depending on outside air temperatures.