Summer and winter performance of an innovative concept of Trombe wall for residential buildings

Abstract

Passive solutions in buildings are being recently rediscovered since they allow rational use of solar radiation, promoting energy savings. Trombe walls, although initially conceived for sole winter heating, if properly managed, can be also used in a Mediterranean climate where the risk of indoor overheating occurs. This study introduces an innovative configuration of a modular Trombe wall that can be easily integrated into existing buildings, providing benefits in both the winter and summer seasons. Simulations with DesignBuilder were performed to evaluate the energy savings in a hot Mediterranean climate. Proper ventilation strategies, developed as a function of climatic parameters, were investigated to exploit Trombe Wall in reducing also summer thermal needs. Results demonstrated that a well-managed Trombe wall can be regarded as an interesting solution to achieve energy savings both in summer and winter. The implemented ventilation strategies allow for reducing electric demand for air-conditioning by 10.5% compared to a traditional envelope configuration and, assuming proper management of the shading system and natural ventilation, cooling needs can be limited by 9.5%. The proposed system is profitable with a discounted payback lower than 6 years, allowing for reducing CO2 emission of about 185 kg per year by considering two reference rooms of an existing building.