Energy Performance Comparison between Two Liquid Desiccant and Evaporative Cooling-Assisted Air Conditioning Systems

Abstract

This study investigated the annual energy saving potential and system performance of two different evaporative cooling-based liquid desiccant and evaporative cooling-assisted air conditioning systems. One system used an indirect and direct evaporative cooler with a two-stage package to match the target supply air point. The other was equipped with a single-stage, packaged dew-point evaporative cooler that used a portion of the process air, which had been dehumidified in advance. Systems installed with the two evaporative coolers were compared to determine which one was more energy efficient and which one could provide better thermal comfort for building occupants in a given climate zone, using detailed simulation data. The detailed energy consumption data of these two systems were estimated using an engineering equation solver with each component model. The results showed that the liquid desiccant and dew-point evaporative-cooler-assisted 100% outdoor air system (LDEOAS) resulted in approximately 34% more annual primary energy consumption than that of the liquid desiccant and the indirect and direct evaporative-cooler-assisted 100% outdoor air system (LDIDECOAS). However, the LDEOAS could provide drier and cooler supply air, compared with the LDIDECOAS. In conclusion, LDIDECOAS has a higher energy saving potential than LDEOAS, with an acceptable level of thermal comfort.

Effect of Evaporator Position on Heat Pump Assisted Solid Desiccant Cooling Systems

“…Chuanshuai Dong et al took a commercial building consisting of five floors of retail and 24 floors of office as the building case and proved that the solar-assisted plate-type liquid desiccant air-conditioning system has a certain energy saving effect (9%) [4]. Hye-Jin Cho and Su Liu et al studied a liquid desiccant-assisted evaporative cooling system for office buildings in terms of indoor comfort [5] and energy consumption [6]. In contrast, the hybrid solid desiccant cooling system can be used as an air-conditioning unit for residential buildings with small thermal loads and diverse cooling needs.…”