1999 Volume 64 Issue 519 Pages 55-62
Thermal environments, indoor air quality, and ventilation effectiveness were measured and evaluated in an office installed both with floor-based and ceiling based systems. Two systems were compared. Major findings are as follows : 1. The horizontal air temperature gradients were within acceptable range and almost same for both systems. 2. The LPPDs were found less than 6% except 6.25% for ceiling-based system in summer. 3. Air temperatures and Δ EHTs at lower level with floor-based system tended to be cooler than those for the ceiling-based system. However the differences were not significant. 4. Subjective acceptability for indoor air quality was no difference between two systems. However lower figures were observed for floor-based airconditioning system in terms of the concentration or the number of air-born particles. 5. Ventilation performance index was greater for the floor-based system than the ceiling-based system. This field study quantitatively makes it clear that floor-based system can provide comparable thermal environment and better air quality in comparison with the ceiling-based system.
