Paper Conference

Proceedings of eSim 2006: 4th Conference of IBPSA-Canada

     

A COMPARATIVE STUDY OF UNDERFLOOR AIR DISTRIBUTION SYSTEM AND CEILING VENTILATION SYSTEM: CFD SIMULATIONS

Liang Zhou, Amid Shakeri, Soheil Rastan, Karen Pero, Edward Morofsky, Hongyu Huang, Edward Kutrowski, Fariborz Haghighat

Abstract: The purpose of this study was to fully understand the influence of the underfloor air distribution (UFAD) and the conventional ceiling air distribution systems on the indoor environment in a real open-plan office using Computational Fluid Dynamics (CFD) methods. Based on that, the near optimal ventilation system arrangement and operating state can be estimated, so as to maintain acceptable comfort level and air quality in the office without compromising the energy efficiency of the ventilation systems. The open-plan office investigated was located in a government office building in Ottawa, which is currently using nozzle diffusers integrated with personal environmental control (PEC) capability. The performance of nozzle diffusers integrated with PEC was previously investigated and compared with in-situ measurements. Another CFD model is built by substituting the ceiling system with UFAD. In this study, the simulation results give detailed description of the parameters related to thermal comfort of occupants, ventilation efficiency and energy consumption. For both UFAD and ceiling system, the range of system configuration and parameters investigated includes: (1) supply airflow rate; (2) supply air temperature; (3) location of diffusers with respect to occupant; (4) heat load density. Indoor air temperature, air velocity, mean age of air, Predicted Mean Vote (PMV), Air Change Effectiveness (ACE), and Air Diffusion Performance Index (ADPI) were estimated to investigate the performance of the ventilation system during occupancy.
Pages: 126 - 133
Paper:
esim2006_126_133