A comparison of an underfloor air distribution system and a mixing system: Measurements and CFD simulations

Abstract

The main objective of this study is to compare the performance of an Underfloor Air Distribution (UFAD) system with that of a mixing ventilation system (MS) in a controlled environment chamber. Velocity and temperature data collected were used for the validation of a computational fluid dynamics (CFD) model. Simulations were then performed using the RNG k-ε turbulence model and the indoor zero-equation turbulence model to examine the applicability of those two models to the present problem. Based on that measured data and simulation results were employed to examine the ventilation efficiency and thermal comfort level resulting from the two ventilation systems. The criteria for air quality and thermal comfort evaluation include: the Air Change Effectiveness (ACE), Predicted Mean Vote (PMV), room air temperature stratification, and air velocity.