Experimental study on the performance evaluation of active chilled beams in cooling operation under varied boundary conditions

Abstract

This study investigates the thermal comfort and indoor air quality performance of Active Chilled Beams (ACB) in cooling operation mode in an open office environment with asymmetrical loads. Many studies on thermal comfort using ACB in cooling mode have been conducted; most of the studies confirm that thermal comfort is satisfactory because the temperature gradient and the airspeeds are acceptable at the occupant level. However, these studies do not specifically address the local discomfort in cooling mode. Furthermore, these studies do not consider performance under different ACB configurations or varied boundary conditions such as those found in real offices. This paper reports the results of an experimental study that addresses the above issues. A laboratory experiment was designed to simulate a multi-occupant open office with an ACB subjected to asymmetric boundary conditions. The results demonstrate that discomfort draft risk at the ankle level is higher when the ACB is oriented parallel to the window. Furthermore, the results suggest that shape (the type of ACB) and throw of ACB affect air distribution. The results emphasize the importance of properly selecting, orienting, and designing ACB, not just to offset the room loads, but to match the proportions and boundary conditions of the office.