Simulation studies on the energy performance of dedicated outdoor air system in air-conditioning

The purpose of this project was to do a simulation study on energy performance of the conventional Variable Air Volume (VAV) and Dedicated Outdoor Air System (DOAS) system under Singapore weather condition with the aid of the Energy Plus Program (EPP) simulation software. VAV system is a conventional centralized HVAC system which United State of America (USA) found that the energy consumption was relatively high compared to DOAS. DOAS is another type of HVAC system that decouples latent and sensible load. Latent load is control by a dehumidifier and sensible load is control by a sensible cooler. The author used solid desiccant unit (SDU) as the dehumidifier and radiant panel cooling system (RPCS) as the sensible cooler for the DOAS model. The conventional VAV system was also modeled and compared with the DOAS to determine the DOAS implementation feasibility in Singapore. The simulation was done under a 3 zones envelope with window at the side of the side zones. The simulation data with the HVAC system models were then obtained and compared. It was found that DOAS consume an average of 50% less cooling energy than VAV system to bring the room to desire cooling temperature and relative humidity. This large saving was mainly due to the chiller in DOAS which consumed 40% lesser energy. Other components such as circulation pump and supply fan also contributed in the saving in DOAS. There were additional electrical consumption from the SDU, thus, it was ultimately revealed that DOAS could save an average of 7.6% of electricity than conventional VAV system in a month.Bachelor of Engineering (Mechanical Engineering