Airside Economizer Low Limit Effect on Energy and Thermal Comfort

Abstract

A continuous effort exists within the heating, ventilating, and air conditioning industry to not only enhance thermal comfort within indoor environments, but also for developing more energy efficient systems. An airside economizer can assist with the latter. Guidance is lacking for these devices in regards to the optimal airside economizer low-limit setpoint temperature; this low-limit is the air temperature when the flow rate of outside air brought in is increased above the minimum airflow needed for ventilation. Researchers have not examined the low-limit's effect on energy conservation in great detail, even though basic airside economizers have been in use for many decades. This thesis provides an examination of the airside economizer's performance. It considers how low-limits affect energy consumption through an examination of different climate zones and a computational analysis. More importantly, this study provides a practical method for predicting the optimal low-limit of an airside economizer. Future research needed to improve the effectiveness of this control scheme is then suggested.