ASHRAE Research Project 1121-RP, Evaluating the Ability of Unitary Equipment to Maintain Adequate Space Humidity Levels: Phase 1, was established to develop a plan to guide the evaluation of humidity control by unitary HVAC equipment. Part of the development of the plan involved the evaluation of dehumidification requirements in different building applications and different climates. This paper describes the analysis of building load characteristics to identify and describe key factors that affect humidity control in various commercial building applications. The results indicate that ventilation loads dominate the dehumidification characteristics of most commercial buildings and dramatically affect the sensible heat ratio (SHR) of the system loads. In most cases, the dehumidification requirements are beyond the capability of conventional unitary HVAC equipment.

Units: Dual