Paper Conference

Proceedings of ASim Conference 2016: 3rd Asia conference of IBPSA-China, Japan, Korea


Impact of the Perimeter Zone Diffuser Slot Angle on Room Air Stratification and Energy Performance in Underfloor Air Distribution System

S. Yeon, J. Son, B. Seo, K. Lee

Abstract: Recently tendency to introduce an underfloor air distribution (UFAD) system for environmentally friendly buildings as an alternative to OH systems clearly increased. Also LEED which is a green building certification system developed by the U.S. Green Building Council proposes UFAD to be the system having improved control and efficiency. This study, by using the Phi-Gamma formula, aims at assessment of the energy performance and temperature stratification according to the variation of a diffuser slot angle from vertical in perimeter zones. Through the EnergyPlus simulation which is validated by both bench-scale and full-scale experiment, the analysis on the energy consumption depending on the diffuser slot angle was conducted in the three-story office building. As a result, stratification was improved with an increase in the vertical angle of the diffuser and thus cooling load was reduced during the summer. However, it showed an increase in energy consumption in the boiler. The reason is that the mixed air temperature is increased despite the reduction of AHU supply air volume. Therefore the energy saving effect was insignificant.
Keywords: UFAD, Room air stratification, Energy performance, Discharge angle from vertical, EnergyPlus