Energy and performance analysis of solar solid desiccant cooling systems for energy efficient buildings in tropical regions

Abstract

Due to Malaysia's high ambient humidity, the majority of buildings suffer from over-cooling and high-energy consumption of conventional cooling systems. This study investigated the feasibility of solar desiccant cooling systems as alternatives to conventional cooling systems for energy-efficient buildings in Malaysia. The performance of a fan coil unit (FCU) and three solar desiccant cooling systems for use in a seminar room with a high latent load has been compared and evaluated. The FCU performance was evaluated using an energy audit, while desiccant cooling systems were simulated using TRNSYS and validated by experimental measurements. The energy audit results showed that FCU could not provide thermal comfort conditions since the room's relative humidity (77.2%) was more than 50%, while the greatest energy usage (37%) was consumed for the dehumidification process. The simulation outcomes demonstrated that the solar hybrid desiccant cooling system with 17.3% energy-saving potential was feasible for buildings with a high latent load. The two-stage solar desiccant cooling system in ventilation and recirculation modes provided 27.9% and 33.9% energy saving, while the room temperature and relative humidity could be brought closer to 25.5 °C-25 °C and 61%-66% respectively. It was found that the solar hybrid desiccant cooling system with COP and the solar fraction of 0.84 and 0.615, respectively, was able to reduce 256.4 kg CO2 emissions per month.

Keywords

• Energy saving
• Desiccant cooling
• Solar energy
• Hot and humid weather
• Thermal comfort