Trombe wall's thermal and energy performance—A retrofitting approach for residential buildings in arid climate of Yazd, Iran

A Trombe wall is a passive solar technology attached to the building envelope to reduce energy demands. In warm climates, due to overheating problems in the cooling season, its efficiency is limited and proper operation is required. In this study, the thermal behavior of a bedroom of a house equipped with a Trombe wall in Yazd with a hot and arid climate under different design configurations and various masonry materials were investigated using the dynamic simulation software DesignBuilder. Monthly ventilation strategies and a schedule of blinds for external glass cover throughout the year were proposed to optimize its energy efficiency. The blinds are applied for shading solar irradiance during summer. They also increase the system's thermal resistance during winter nights. According to the results, a concrete Trombe wall with 2/3 of the façade area is capable of reducing the heating load by 86%. However, its function for summertime is negative, and even in the insulation mode, it can increase the cooling load by 5%. Natural ventilation with the Trombe wall is applicable during moderate seasons; however, its cooling efficiency is limited compared to cross ventilation. The results also highlight that retrofitting a room with a Trombe wall can reduce the annual energy demand by 63%, which is equal to a reduction of 124 kg CO₂ emission.