Thermal and ventilation characteristics in a room with underfloor air-conditioning system.

It is the objective of the present paper to investigate indoor environmental characteristics ofan office building with an underfloor air conditioning system. Thermal conditions in the roomwere monitored including horizontal and vertical temperature distributions, supply andexhaust air temperatures, and globe temperature. Indoor air quality was investigated bymeasuring carbon monoxide, carbon dioxide and airborne particulate. Velocity distributionsaround a floor air terminal, and thermal comfort around a supply air terminal were alsoinvestigated. Room ventilation characteristics were obtained by a pulsed tracer gas technique.It shows that the underfloor air conditioning system provides good ventilation characteristicsin cooling modes, while airborne particulate levels are comparable with those found inconventional ceiling supply systems. The detailed temperature and velocity information canbe used to design the floor layout to improve the performance of the UFAC systems.