A study on the performance of the air conditioning system at the Asian Institute of Technology | |
| Author | Chalamalasetty, Chiranjeevi |
| Call Number | AIT Thesis no.ET-17-15 |
| Subject(s) | Air conditioning--Efficiency--Asian Institute of Technology Air conditioning from central stations--Asian Institute of Technology |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Energy |
| Publisher | Asian Institute of Technology |
| Abstract | Buildings account for 40% of the global primary energy consumption and the major energy consumption in the building is for HVAC systems. In tropical regions, air conditioning accounts for up to 60% of the total energy consumption in commercial buildings. The air conditioning at the Asian Institute of Technology (AIT) consumes about 300,000 kWh per month, and accounts for a significant share (30%) of the institute’s electricity consumption. This study was aimed to assess the current energy performance of air conditioning system at AIT, and suggest options for its improvement. The methodology included literature review ,experiments and analysis to assess the current energy performance of the AIT air conditioning system; the work included study of the (a) comfort conditions at the end use (rooms/buildings), (b) heat gain in the chilled water distribution network and measures to reduce the heat gain, and (c) operating conditions of the chiller and its accessories to decrease the specific energy consumption of the chillers. Efforts on these three fronts would help in increasing the overall performance of air conditioning system. The experimental observations of thermal comfort inside selected rooms of the Energy building indicated that the rooms are within the recommended comfort zone only for 35% of the working time. This is mainly due to the high chilled water supply temperature to the room fan coil units. Specific issues in the buildings in terms of leakages, broken ceilings and damaged thermostats were identified. Operation of a decentralized air conditioning system showed that the conditions are always in the recommended comfort range. Also, the specific energy consumption of the decentralized system is lower than that of a centralized air conditioning system. Using a multi split VRV system at Energy building can provide better cooling comfort to the occupants and eliminate the heat gain in the distribution network; moreover, the electricity economized by the use of such a system would help to recover the capital investment in less than 2 years. The heat gain in the chilled water network between the chiller plant and Energy, SOM, Administration/AITCC buildings was estimated to be about 150-200 RT, almost equal to 28% and 50% of the load on the chillers, during day time and night time respectively. Based on the experimental observations, changing the insulation of the chilled water network can save about 2 million Baht/year, with a payback of around 1.6years. Measurement of relevant parameters at the chiller system indicates that the chillers were being operated at very low part load conditions during certain periods of the day, resulting in very high specific energy consumption (SEC) of the chillers(as high as 1.5 kW/RT). The chilled water and cooling water pumps account for about 34% of the total electricity consumption of the entire chiller system. This is high because of the constant speed operation and low pump efficiencies. Operating chilled water pumps 1 and 5 can save around 30,000 kWh/year. The overall specific energy consumption of the overall air conditioning system varies from 1.3 to 1.6 kW/RT. Overall, 30% savings in the electricity consumption can be achieved at AIT by implementing the recommendations suggested -1,077,879 kWh/year equivalent to 4,311,516 Baht/year. |
| Year | 2017 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Energy and Climate Change (Former title: Department of Energy, Environment, and Climate Change (DEECC)) |
| Academic Program/FoS | Energy Technology (ET) |
| Chairperson(s) | Kumar, Sivanappan; |
| Examination Committee(s) | Mohanty, Brahmanand;Salam, Abdul P.; |
| Scholarship Donor(s) | Asian Institute of Technology Fellowship; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 2017 |