Integrated desiccant cold air distribution system

Strong design trends toward the use of cold air distribution systems, which generally operate with owe supply air temperatures (i.e., 40{degrees}F to 45{degrees}F), provide unique opportunities to enhance the cost effectiveness of physically integrated desiccant and evaporation cooling and air-handling components of variable-air-volume (VAV) systems. With higher outdoor ventilation rates required by the proposed ASHRAE Standard 62-1981R, a higher premium cost is incurred for refrigerating this air to a 40{degrees}F or 45{degrees}F supply air temperature if cooled by conventional air-conditioning methods. The newly developed integrated desiccant cold air distribution methods. The newly developed integrated desiccant cold air distribution (IDCAD) system can work with a variety of conventional or advanced direct gas-fired desiccant regeneration developments expected to be commercially available in the near future. The IDCAD air-handling unit employs three supply fans: one for the hot deck and two for each cold deck, thereby allowing for separation of ventilation rates for both exterior and interior occupied zones. This design feature allows for significant reductions in the amount of building return air in ductwork while permitting low containment space levels than conventionally designed VAV systems within separately served interior and exterior occupied building spaces.