“The contribution of double skin roof coupled with thermo reflective paint to improve thermal and energy performance for the ‘Mozabit’ houses: Case of Beni Isguen’s Ksar in southern Algeria”

Abstract

In traditional cities of hot and arid climate regions, roofs are usually the surfaces most exposed to intense sunlight in summer. This leads to high temperatures inside the houses and forces the inhabitants to escape to the terraces at night. On the other hand, some residents use air conditioning and therefore increase energy consumption. This work aims to study the contribution of a double skin roof coupled with a thermo-reflective paint on the reduction of indoor temperature and energy consumption in house located in the Ksar of Beni Isguen in southern Algeria. Firstly, the problem of overheating was identified through temperature and humidity measurements for traditional dwelling in hot season. Secondly, a model of double skin roof coupled with thermo-reflective paint was developed and numerically simulated using TRNSYS software. The obtained results showed that in summer, the temperatures in traditional houses are high compared to the comfort zone. The average indoor operating temperatures exceeded 37 °C during different hours of the day, over the investigation period of three representative days of hot season. Nevertheless, the proposed model reduces the indoor operative temperature by 5 °C. Also, the model was validated against in situ measurements, whose results showed a consistency between the measured and simulated temperature values. In addition, thermal simulation results performed over a period of one year indicate that the overall energy consumption required for cooling loads is reduced by 572 kWh i.e. 66% when optimizing the roof thermal performance.