A Study on the use of Lithium Chloride solution and Calcium Chloride solution to Dehumidify in Air-Conditioned Rooms to Reduce Energy Consumption in Air Conditioners

Abstract

This research investigated the use of lithium chloride (LiCl) and calcium chloride (CaCl₂) solutions as liquid desiccants for moisture absorption from air. The desiccant solution was stored in a reservoir located at the base of the liquid desiccant dehumidifier unit and circulated by a dedicated pump. The entire system was installed inside a test room measuring 2 m × 2 m × 2 m to reduce the latent heat load of a small-scale split-type air conditioning system. The experimental chamber was constructed with 0.2 m thick Expanded Polystyrene: EPS insulated walls. The test conditions were established as follows: indoor air temperatures were set at 30°C 35°C and 40°C, with corresponding relative humidity levels of 70% 80% and 90%. The results showed that the electrical energy consumption of the air conditioner without a desiccant system ranged from 0.182–0.192 kWh at 30°C 0.208–0.255 kWh at 35°C and 0.259–0.337 kWh at 40°C. When LiCl solution was used as the moisture absorbent, the electrical energy consumption of the air conditioner decreased by 0.020–0.020 kWh at 30°C, 0.011–0.042 kWh at 35°C, and 0.040–0.082 kWh at 40°C. Similarly, when CaCl₂ solution was applied, the energy consumption was reduced by 0.036–0.043 kWh at 30°C –0.005–0.036 kWh at 35°C, and 0.019–0.064 kWh at 40°C. The maximum reduction in electricity consumption achieved by the LiCl solution was 24%, while the CaCl₂ solution achieved a maximum reduction of 23.62%. In terms of comparative performance, CaCl₂ showed better energy-saving potential at 30°C, both solutions performed comparably at 35°C, and LiCl demonstrated superior performance at 40°C.