Evaluating Thermal performance of Earth-sheltered Buildings in Heating Season(Case Study: Hot-Arid Climate of Yazd)

Abstract

This study is done with the aim of evaluating heat loss of earth-sheltered buildings in heating season in comparison with conventional buildings above the ground. Literature review of earth-sheltered architecture shows that although this idea has a long rich history in Iranian architecture and urban design, limited researches related to evaluating thermal performance of this kind of structures has been done. Additionally, previous researches have usually considered thermal behavior of earth-sheltered buildings in cooling season and neglected the effect of earth’s thermal stability on mitigating heat loss in heating season. In this research, different modes of contact with earth are modeled for an earth-sheltered building in the city of Yazd and the heat loss in heating season is calculated and compared with buildings above the ground. In addition, to calculate soil temperature, the formula developed by Labs, is employed. The findings show that heat losses of earth sheltered models decrease with increasing contact with earth’s surface, insomuch that heat loss in a model with three surfaces in contact with earth (North, East & West), was estimated about 44% of the model above the ground. Altogether, it can be concluded that earth-sheltered architecture can make considerable energy savings during heating season in hot arid climates.