Improving the energy efficiency of existing residential buildings by applying passive and cost-effective solutions in the Hot and humid region of Iran

This paper aims to investigate the improvement of the energy efficiency of typical apartment buildings in the hot and humid region of Iran by applying passive and cost-effective solutions. For this purpose, a residential building, that reflects the current typology, is selected in Bushehr, Iran, and its annual energy consumption is explored using electric and gas bills. Then, a primary and calibrated model of the building is made using a real occupancy schedule and hourly weather data of Bushehr in Design Builder Software to simulate its energy performance. Considering the architectural design of the baseline model and using passive solutions (including low-E glazing, thermal insulation of external walls, roof and ceilings, and pre-heating of domestic hot water), a developed model is made. The simulation results indicate that the annual carbon dioxide emission and energy consumption of the developed model is reduced by 18.7% and 20%, respectively. These passive solutions can be used to improve the energy efficiency of existing buildings to achieve low Carbon buildings and neighborhoods in this part of Iran. This study also proposed a new reference for the annual energy consumption of low-energy houses in the hot and humid area of Iran and the Persian Gulf region (75-76 kWh/m2/Year). Moreover, the economic analysis in this study demonstrates that the above-mentioned passive solutions will be cost-effective if the government subsidies for the residential buildings’ energy use are eliminated in this region.