Reducing overheating risk in naturally ventilated houses through the design of compressed Earth blocks walls in hot dry climate

Abstract

PurposeAppropriate thermal properties of walls can lead to the improvement of the indoor environment of buildings especially in countries with low energy availability such as Burkina Faso. In order to benefit from these advantages, the thermal properties must be properly characterized. This paper investigates the impact of the design of single- and double-layer walls based on compressed Earth blocks (CEB) on the risk of indoor overheating.Design/methodology/approachFirst a building has been used as a tool to measure climate data. Then, a software program was used to define an accurate thermal model. Two indices were defined: weighted exceedance hour (WEH) related to the risk of overheating and cyclic thickness (ξ) related to the thermal properties of the walls. The aim is to define the appropriate values of ξ which minimized the WEH. The study also assesses the sensitivity of these thermal properties to occupancy profiles.FindingsThe results indicate the arrangements of the thermal properties that can promote comfortable environments. In single-layer wall buildings, ξ = 2.43 and ξ = 3.93 are the most suitable values to minimize WEH for the room occupied during the day and night, respectively. If a double-layer wall is used, ξ = 1.42 and CEB layer inside is the most suitable for the room occupied during the day, while ξ = 2.43 and CEB outside should be preferred in the case of a room with night occupancy profile.Originality/valueThe findings indicate that occupation patterns at room scale should be systematically considered when dealing with wall design in order to improve the thermal comfort.