THE USE OF PHASE CHANGE MATERIAL TO REDUCE PEAK AIRCONDITIONING LOAD IN HOT CLIMATE OF UAE

District cooling systems are increasingly being deployed in hot climates, which constitute around 50% of energy consumption. A considerable improvement in the district cooling system (DCS) performance can create a substantial impact on the energy consumption and capacity installation through storage by reducing the air conditioning peak load. Using a phase change material (PCM) to absorb and release heat offers latent heating and cooling for the environment. This study aims to incorporate a thermal energy storage system (TES) containing PCM that can store cooling contained in chilled water during off peak time and release the same at the peak time to reduce the peak cooling load. A preliminary study was carried out by the authors on involving paraffin based PCM with melting range of 30- 33°C in a thermal energy storage unit. The purpose of this research is to determine the feasibility of a PCM-based air pre-cooling approach that can reduce the peak cooling demand by 20% by storing ambient cooling from the previous night and releasing it to the fresh air supply stream throughout the following day. The PCM containers are positioned towards the hot air as the pre-cooling unit is installed in a standard AC duct, which allows hot air to reach the test chamber at a specific velocity. The study concluded that PCM enhanced the pre-cooling performance and reduced the outlet air temperature. A drop of 5.5°C occur in case velocity of 1 m/s. Air conditioning system reduced capacity reached by 28%. The optimum use of PCM by incorporating chilled water-cooling is under investigation as the district cooling system delivers chilled water to buildings during day and night. However, most of the night times, buildings are not in use thus storing night time chilled water cooling through the PCM and releasing the same during day time is expected to substantially drop the cooling load.