Center for the Built Environment

Ceiling fans may cool room occupants very efficiently, but the air speeds experienced in the occupied zone are inherently non-uniform. Designers should be aware of several generic flow patterns when positioning ceiling fans in a room. Key to these are the fan jet itself and lateral spreading near the floor. Adding workstation furniture redirects the jet’s airflow laterally in a deeper spreading zone, making room air flows more complex but potentially increasing the cooling experienced by the occupants.

This paper presents the first evaluation of the effects of tables and workstation partitions on a room’s generic air flow and comfort profiles. In a test room with a ceiling fan, we moved five anemometers mounted in a “tree” at heights of 0.1, 0.6, 0.75, 1.1, and 1.7 m to sample a dense measurement grid of 7 rows and 6 columns.  We tested five different table and partition configurations and compared them to the empty room base case. From the results we propose a simplified model of room airflow under ceiling fans, useful for positioning fans and workstation furniture.  We also present comfort contours measured in two ways that have comfort standards implications.  The measured data are publicly available on the internet.