Describes an investigation of the ventilation performance of cold air distribution systems in a full-scale test room for three different designs of ceiling-mounted diffusers - a large square radial, a small square radial and two linear diffusers. The supply air temperature was 3.3degC (38degF). Tests were conducted with internal heat loads and with and without furnishings. The local mean ages of air, air diffusion effectiveness and contaminant-removal efficiency were measured using tracer gas techniques to assess the performance of the ventilation system in maintaining adequate air quality conditions in the occupied region. Finds satisfactory air quality and thermal comfort conditions were provided to the occupied areas. Tests were also conducted for selected diffuser designs with a supply air temperature of 12.8degC (55degF) commonly used in conventional air distribution systems and finds no appreciable differences between the two systems.

KEYWORDS: Experiment, ventilation, performance, air temperature, air diffusion, diffusers, thermal comfort, indoor, air quality, testing, comparing