Abstract
The UFAD(Under Floor Air Distribution) system is generally known as more energy efficient and comfortable than the CBAD(Ceiling Based Air Distribution) system. In practice, however, some buildings with the UFAD system have been less effective in energy performance and have been reported for uncomfortable indoor environment. Such problems are due to a failure to consider the features of UFAD system when it is planed, operated and used designs that just meet design standards for conventional the CBAD system. In this study, measurements have been carried out to clarify the temperature difference between occupied and unoccupied zone of an UFAD system. Simplified formula was suggested for estimating the adopted supply air flow rate and RA(Return Air) temperature of HVAC system. By using TRNSYS 16 the energy performance of the UFAD system and the impact of the thermal load of lighting have analysed. Annal energy use of the UFAD system has been evaluated reduction of 13.1% for the CBAD system. And energy saving performance of UFAD system was varied from 1.6% to 16.1% by the proportion of radiative thermal load of the lighting.
