Comparative analysis of standalone and desiccant dehumidifier systems using SSLC in UAE residential buildings: A case study

The UAE's hot climate has led to a critical dependency on air conditioning, with the building sector consuming nearly 90 % of the country's electricity, 80 % of which is attributed to cooling. Under extreme outdoor temperatures, conventional air conditioning systems experience significant efficiency losses, driving up energy consumption and increasing carbon emissions. This paper introduces an innovative desiccant dehumidifier air conditioning system designed to enhance energy performance and meet the unique demands of hot and humid climates. The proposed system combines photovoltaic (PV) panels, a vapor compression cycle (VCC) for sensible cooling, and a desiccant-coated heat exchanger (DCHX) for latent load handling, implementing the Separate Sensible and Latent Cooling (SSLC) method to optimize energy distribution. By isolating sensible load management to the VCC, the system enhances the coefficient of performance (COP). This methodology is rigorously evaluated through TRNSYS simulation for a typical residential villa in Dubai. The results indicate a significant reduction in the total cooling load by 63,751 kW-hr or 23.45 % reduction annually compared to the standalone system. Additionally, the compressor power is reduced by 31,906 kW-hr, or 38.75 % annually. Sensible heat ratio analysis across all zones yields values ranging from 0.66 to 0.82, consistent with the ASHRAE Standard 90.1. On the peak cooling load day, the COP of the desiccant dehumidifier system exhibits a 10.77 % improvement over the standalone system. Moreover, the system reduces CO2 emissions by 25.76 tons annually. The findings reveal the desiccant dehumidifier air conditioning system is highly effective and sustainable solution to address regional energy challenges offering large energy savings and enhancing indoor comfort in hot, humid climates.