Paper Title
CFD Assessment in Passive Heating and Cooling Operations of Underground Shelter for the Malaysian Climate

Underground shelters are built with the intention to serve as specialized shelters that provide either heating or cooling to occupants during different climates, depending on the requirements. In this study, a 3D CFD underground shelter model was investigated throughout different seasons of the year, within Malaysia’s environment. Initially, soil temperature distributions at various depths are numerically investigated using the Kasuda Model, which then shows that, at a depth of 10 m and beyond, the soil temperature remains constant. The simulation model employed in this study is based on Malaysia’s climate and soil thermal properties, which were employed as boundary conditions for the day and night wind profile and temperature. This model was numerically solved using the ANSYS Fluent for accurate simulation results. The simulation computes passive heating and cooling operations within an underground shelter. The results indicate that the temperature of the underground shelter ranges between 27.80 and 32.10℃ from day to night. This assessment was evaluated in the coldest and warmest months of the year. The findings portray that the soil temperature and natural ventilation can effectively reduce energy consumptions within the underground conditioning systems. Lastly, an adequate comfort temperature was measured according to the standard prerequisites. Index Terms - Underground Shelter, CFD Analysis, Soil Temperature, Comfort Temperature.