Energy saving potential of a hybrid HVAC system with a desiccant wheel activated at low temperatures and an indirect evaporative cooler in handling air in buildings with high latent loads

Abstract

Air handling in buildings with high latent loads usually requires a high-energy cost to satisfy the user’s thermal comfort needs. Hybrid systems composed of desiccant wheels, DW, and indirect evaporative coolers, IEC, could be an alternative to direct expansion conventional systems, DX systems. The main objective of this work was to determine the annual energy consumption of a hybrid system with a DW activated at low temperatures and an IEC, DW-IEC system, compared to a DX system to serve air in a small building with high latent loads, such as spas. Several annual energy simulations for 6 climate zones were performed, analysing electric energy consumption, seasonal mean coefficient of performance, SCOP, and energy consumption per unit of dehumidified water, Econs, of each system. The simulations were based on experimentally validated models.The annual energy consumption of the DW-IEC system was lower than that of the DX system for the 6 climate zones, achieving significant energy savings, up to 46.8%. These energy savings resulted in better SCOP values for the DW-IEC system. Therefore, the proposed DW-IEC system has high potential to reduce energy costs, achieving the user’s thermal comfort.