Impact of passive cooling techniques on energy demand for residential buildings in a Mediterranean climate

Abstract

This study presents the thermal analysis of a building prototype, which was designed and built in accordance with energy efficiency measures to improve indoor thermal comfort, particularly in summer. The building prototype is located in Souidania (20 km southwest of Algiers, latitude 36°7N, Longitude 03°2E). The location is characterized by a temperate Mediterranean climate. In order to perform this analysis, various activities are carried out: a series of monitoring campaigns; dynamic simulations with TRNSYS software, calibration of the model with experimental data and comparative study with buildings that use different wall constructions. Based on a validated building thermal model, dynamic analysis is carried out in order to evaluate the impact of thermal mass and of eaves and night ventilation. The results demonstrate that cooling energy demand is more affected by thermal transmittance values than by the envelope thermal mass. A recommended guideline for the optimum overhang length for south-facing windows is proposed. Ultimately, it is found that the combination of both natural ventilation and horizontal shading devices improves thermal comfort for occupants and significantly reduces cooling energy demand.