The study of guideline for energy efficient buildings renovation: A case study in mechanical building 4, King Mongkut's University of Technology Thonburi

In Thailand, the energy consumption in building is quite high, accounting for 17.6% of the country's total energy demand. Therefore, the building sector plays an important role in helping to achieve Thailand Carbon Neutrality 2050 and net-zero Greenhouse Gas emission by 2065. The minimum energy efficiency benchmark in the building, namely Building Energy Code (BEC), is the most important issue in improving energy efficiency in the building sector from the beginning of building design and renewable energy implementation to reach zero energy building. The objective of this research study is to assess Mechanical Building 4, King Mongkut's University of Technology Thonburi (KMUTT) according to BEC standard which consists of the following criterion: Building envelope (Overall Thermal Transfer Value (OTTV) and Roof Thermal Transfer Value (RTTV)), Lighting system, Air-conditioning system, Water heating appliance, Renewable energy, and Whole building energy. In this research, we mainly implement various measures in this building such as a Low-E glass window, LED lamp, efficient air-conditioning and efficient office equipment and computers with energy-saving label. The results are found that total annual electricity consumption is 195,067 kWh. Air-conditioning system represents 83.6% of total electricity use, followed by 10.1% lighting system and others 6.3%. After implementing the measures above, whole annual electricity consumption could be 63,334.7 kWh or 67.5% reduction, comprising a large proportion from air-conditioning system and lighting system at 59.3% and 6.5% respectively. In term of Energy Performance Index (EPI) which is the ratio of annual total electricity consumption with its gross floor area. Its EPI shows a decrease from 184 to 55.6 kWh/m2year. Moreover, Mechanical Building 4 can meet the zero-energy building by installing the PV rooftop of 39 kWp with annual electricity production of 64,038 kWh.