Recent research has reduced the capital cost and increased the performance of regenerative dehumidifiers making new gas-fired hybrid desiccant cooling concepts with low capital and energy costs feasible for medium to large general air-conditioning projects. The fresh air, latent, and part of the sensible heat load on a building may be taken by a desiccant unit consisting of a regenerative dehumidifier, heat exchanger, evaporative cooler, heating coil, and fans. The remaining sensible heat load is taken by a gas engine driven, lead chiller supplying waste heat to fire the desiccant unit and an electric motor driven peak chiller. The lead chiller is sized so its waste heat is just sufficient to fire the desiccant unit at peak cooling load. [n winter, the lead chiller operates, supplying heat through a heat reclaim condenser as well as its waste heat to heating coils, and the desiccant unit recovers heat from the exhaust air. Cooling and heating energy costs can be halved for a negligible increase in capital cost.

Units: SI