Net zero energy buildings in semi-arid climates: An analysis on 3 case studies in Tehran, Iran

This paper analyzes utilization of renewable energy systems and efficient building envelopes in the semi-arid climate. The proposed model evaluates renewable energy systems solutions as well as economic- and energy-efficient construction materials for the net zero-energy buildings (NZEB) in semi-arid climates. The objective of this paper is to optimize total energy cost and environmental impacts in NZEB. Three real case studies in Tehran, Iran, are used for this analysis. Different potential renewable energy systems, including PV panels, solar thermosiphon systems, geothermal heat pumps, and their combinations, are investigated in two residential buildings and a commercial building. Moreover, analyzing building envelopes using thermodynamic characteristics of building surfaces is done. The results show that the implementation of the proposed model in the buildings in semi-arid climates significantly reduces the negative environmental impacts for both residential and commercial buildings, and also increasing their energy efficiency up to 63% and 38%, respectively.