Dehumidification in HVAC Systems
Order Number: SYS-APM004-EN
Publish Date: 2002
Discusses the dehumidification of HVAC systems when it comes to performance of various, cold-coil commercial, particularly at part-load conditions.
Why control humidity in buildings?
Sources of moisture
Cold coil versus desiccant dehumidification
Full-load versus part-load conditions
ASHRAE weather data
Dehumidification performance of constant-volume systems (packaged direct expansion DX equipment, energy recovery, fan-speed adjustment, mixed-air bypass, return-air bypass, DX coil circuiting, dual path air handlers, supply-air tempering or reheat)
Dehumidification performance of VAV systems (minimum airflow settings, supply-air temperature reset, supply-air tempering at VAV terminals, colder supply-air temperatures)
Dedicated outdoor-air systems (neutral versus cold, to space versus to other units, reset control strategies)
Unoccupied humidity control
Building pressure control
Airside economizer control
ASHRAE Standards 62 and 90.1