Comparison of age of air and air change effectiveness between supply diffuser types

공조취출방식에 따른 공기의 나이 및 환기효율 비교

In this study, three different supply diffuser types(desktop, floor and ceiling) are compared in view of their ability to distribute supply air to the workstation breathing zone. The measurements on the age of air and the air change effectiveness using the tracer gas method are carried out to analyze the ventilation performance for provision of fresh air between the diffusers. The desktop diffuser type could deliver air directly to the occupants breathing zone with a high degree of effectiveness. The measured local air change effectiveness of the desktop diffuser in the breathing zone was usually 1.13 to 1.23 times greater than that of ceiling and floor diffusers. When the minimum outside air change rate as specified using ASHRAE Standard 62R is supplied with a desktop diffuser type, the volume of outside air can be reduced 13 to 23%, resulting in a commensurate in ventilation energy use.