Experimental investigation of chilled ceiling air-conditioning system

In Singapore where the climate is hot and humid, conventional air condition system is a popular choice and widely used by most buildings in Singapore. Commercial buildings use air handling units (AHU) while HDB flats use split units. These units involve the use of mechanical fan driving the air through a cooled medium such as chilled water, effectively lowering the temperature of the air and cooling the room when the cold air enters the room. However, the process of cooling the air requires the medium to be of a very low temperature since the temperature difference between the air and the chilled water has to be quite large, which requires high energy to lower the temperature of the water. The use of the mechanical fans to introduce the air movement also consumes significant energy. To improve the efficiency of the air conditioning system, a chilled ceiling panel system could be used. The chilled ceiling panel system is already popular in Europe as it need not have to use chilled water that requires such a low temperature since the temperature difference between the chilled water and the air need not be so large. As such, it consumes less energy. Moreover, the air in the room can move via the natural convection, hence removing the need of a mechanical fan, which further reduces the energy consumption. A drawback of the chilled ceiling system when compared to the conventional system is the need of a separate dehumidifier to reduce the humidity level of the air. This extra consumption of energy has to be investigated to effectively compare the energy efficiency of the chilled ceiling panel and the conventional system. A set up of the chilled ceiling panel system is tested. The results obtained were compared with a simulation of a conventional system under the same conditions. The experimental results shows that even though the chilled ceiling panel system has an extra dehumidifier energy consumption, the overall energy consumption is still lower than as compared to the conventional system. This shows that the chilled ceiling panel system can save energy and hence lower the costs of running the system. However, the desired room temperature cannot be too low as it will increase the risk of condensation for the chilled ceiling panel system.Bachelor of Engineering (Mechanical Engineering