A Comparison of Energy Consumption in an Underground Building with a Similar On-ground Model in the Climates of Tehran, Yazd, and Tabriz

The limited resources of energy, the significant rise in energy consumption, and its devastating effects on the environment are among reasons to save and optimize energy consumption. To minimize the dependence on energy, innovative low-energy structures can be built. Since the maximum amount of energy (about 40 percent) is consumed in the building sector and most of it is spent in cooling, heating, and ventilation systems, passive design solutions can help reduce this amount. One of the ways to reduce the total energy requirement of a building is to replace conventional above-ground buildings with underground structures. This study examines the pattern of heat exchange, heat gains and losses to identify the principles that make earth-sheltered buildings significant energy conservation systems. The subsurface walls at varying depths have a direct impact on energy consumption and the environment. In this study, soil temperatures in Tehran, Yazd, and Tabriz were calculated by using a thermal model. Separate analyses of an above-ground building and an earth-sheltered building exposed on its south side at depths of 1-6 meters were carried out in Energy Plus to determine the energy consumption and ultimately the energy efficiency. The simulation results showed that due to soil parameters considered for each climate, the amount of energy savings in Yazd is more than Tehran and Tabriz. In general, underground buildings in the hot and dry climates are more efficient especially during the summer, to the extent that the cooling load reaches zero at some depths.