Total Building Air Management: When Dehumidification Counts

Abstract

Industry trends toward stringent indoor air quality codes, spearheaded by ASHRAE 62-89: Ventilation for Acceptable Indoor Air Quality, present four challenges to the building industry in hot and humid climates: 1. Infusion of large quantities of make-up air to code based on zone requirements 2. Maintenance of tight wet bulb and dry bulb temperature tolerances within zones based on use 3. Energy management and cost containment 4. Control of mold and mildew and the damage they cause Historically, total air management of sensible and latent heat, filtration and zone pressure was brought about through the implementation of non-integrated, composite systems. Composite systems typically are built up of multi-vendor equipment each of which perform specific, independent functions in the total control of the indoor air environment. Composite systems have a high up-front cost, are difficult to maintain and are costly to operate. Today, emerging technologies allow the implementation of fully integrated system for total building air management. These systems provide a single-vendor solution that is cost effective to purchase, maintain and operate. Operating saving of 23% and ROIs of 2.3 years have been shown. Equipment specification is no longer based primarily on total building load. Maximum benefits of these dynamic systems are realized when systems are designed with a total operating strategy in mind. This strategy takes into consideration every factor of building air management including: 1. Control of sensible heat 2. Balance management of heat rejection 3. Latent heat management 4. Control of process hot water 5. Indoor air quality management 6. Containment of energy consumption 7. Load shedding