A SIMULATION BASED STUDY FOR CONVERTING A SEVEN STOREY GREEN MARK INSTITUTIONAL BUILDING INTO A NET ZERO ENERGY BUILDING

Abstract

Aiming to have “Positive-energy Low-rise, Zero-energy Medium-rise, Super Low-energy High-rise buildings in the tropics”, in a land scarce country like Singapore, existing building energy retrofits are essential. Building energy simulation tools are widely used in the industry to estimate the building energy performance and evaluate potential retrofit alternatives in developing Net Zero Energy Buildings. However, the potential of using simulation tools to convert an existing Green Mark institutional building remains unclear. Hence, this dissertation studies the possibility of converting an existing Green Mark building to net Zero Energy building through identifying possible retrofit options using energy simulation model. NUS Block AS8 is selected as an energy retrofit case study carried out through building energy modelling tool named Integrated Environmental Solutions Virtual Environment (IES-VE). The study involves two major parts namely baseline model development and energy retrofit analysis. The baseline model has established a NMBE and CV (RMSE) of -2% and 9.3% respectively through calibration process which is within the calibration acceptance criteria. Next, retrofit options that are suitable for simulation modeling is identified and filtered through sensitivity analysis. Then, the options are applied individually on top of the baseline model for further energy performance study. Amongst the 6 retrofit options identified, improving the energy efficiency of AHU was found to have the greatest impact on the building energy performance. After integrating the retrofit designs, it is found that 50% energy savings could be achieved upon the building retrofit. In order to achieve a nZEB based on the proposed retrofitted building, the energy consumption should be further reduced by 77% or the renewable energy generation should be further increased by 335%. This study has covered multiple facets of baseline model development, calibration, sensitivity analysis and building retrofit energy performance studies for the aim to convert an existing Green Mark institution into Net Zero Energy Building. This study process could serve as a basis for the future studies on the possibility to achieve a Net Zero Energy Building through retrofit based on the existing Green Mark building.