Energy performance analysis of a solar-cooled building in Tunisia: Passive strategies impact and improvement techniques

The energy performance of a solar cooled office building located in Tunisia is studied using the TRNSYS software. The simulations assessed the real case study and analysed the impact of its architectural characteristics and passive techniques on its energy requirements. The impact of solar passive heating techniques already implemented in the envelope is studied in order to take advantage of them in winter and prevent their overheating effect in summer. Besides, additional passive cooling solutions are proposed and studied aiming to decrease the cooling requirements. The results showed that the insulation of the walls and the cool roof guarantee important savings of 46% in winter and 80% in summer compared to an ordinary building. The study was also focused on the impact of the trombe walls and showed that the heating requirements are raised by 20.7% if the storage walls are omitted from the construction. The integration of internal curtains in the windows and movable solar overhangs shading the storage walls and the low-emissive Argon coatings allowed a relevant reduction in total energy demands: 60.3% for heating demands and 47.7% for cooling demands. The peak cooling load has decreased from an initial value of 14.09-8.68 kW. Thanks to this relevant reduction, a technical improvement solution consisting in a cooling storage was proposed to increase the solar cooling performances.