Study of the dynamic thermal behavior of the walls of standard constructions in Madagascar

Passive housing guarantees a comfortable indoor climate in all seasons without having to resort to expensive systems in terms of energy consumption.Building materials, thanks to their thermal inertia, the ability on the one hand to slow down and attenuate the propagation of thermal wave fluctuations and on the other hand to absorb and store energy, play a major role in this sense.The object of this article is to determine the thermal inertia of earth-based walls, shaped in brick or not, typical envelopes of dwelling houses in Madagascar.The study is based on the dynamic thermal characteristics defined by the international standard ISO 13786.This also specifies the methodological for their calculations.The results are intended to guide the choice integrating thermal comfort with low energy consumption in future constructions.They show that the thickness of the wall has a significant effect on the time lag as well as the decrement factor of the daily variations of the temperature.It follows that, compared to brick walls, rammed earth walls present a greater capacity to absorb, store and release heat.It can be deduced that building designed with such an envelope provide better thermal comfort during hot seasons in the highlands where tropical climate is tempered by altitude and throughout the year in other regions.These encouraging results prove that traditional earth constructions have their place in sustainable building today.