A Psychrometric Approach to Air-Side-Economizer Limits, Part 1 of 2

Constant-volume air-conditioning systems control space air temperature directly and humidity indirectly by modulating or cycling the cooling apparatus. This article examines the effect of economizer operation on the comfort of spaces served by constant-volume air-conditioning systems.

As they relate to integrated operation, the ideas presented here are applicable primarily to direct-expansion (DX) systems with limited unloading capability; however, many also apply to chilled-water s