Analysis and design of room air distribution systems

This article analyzes room air distribution and describes a design chart that makes it possible to evaluate variables such as air quality, air speed and draft rate (DR), temperature gradient (PDgrad), mean radiant temperature, and radiant temperature asymmetry (PDrad) as a function of flow rate and temperature difference in the supply system. Five different air distribution systems are analyzed: mixing ventilation from a wall-mounted diffuser, mixing ventilation from a ceiling-mounted diffuser, mixing ventilation from a ceiling-mounted diffuser with swirling flow, displacement ventilation from a wall-mounted low-velocity diffuser, and a low-impulse system based on a textile terminal in the ceiling. The procedure to some extent can be based on flow elements, but especially full-scale experiments and computational fluid dynamics predictions have been used for the development of the design charts described herein.