Simplified Air Change Effectiveness Modeling

This paper describes recent progress in developing practical air change effectiveness modeling techniques for the design and analysis of air diffusion in occupied rooms. The ultimate goal of this continuing work is to develop a simple and reliable ?method for determining heating, ventilating and air conditioning (HV AC) system compliance with ventilation standards. In the current work, simplifiedtwo-region models of rooms are used with six occupancy patterns to find the air change effectiveness. A new measure, the apparent ACH effectiveness, yields the relative ventilation performance of an air diffusion system. This measure can be used for the prediction or evaluation of outside air delivery to the occupants. The required outside air can be greater or less than that specified byventilation standards such as ASHRAE Standard 62-89.