Dynamic assessment of the thermal performance of hemp wool insulated external building walls according to the Moroccan climatic zoning

Abstract

Abstract This paper deals with the assessment of the dynamic thermal performance of Moroccan external walls. Firstly, based on the quadrupole method, the thermal capacity and thermal resistance of an uninsulated brick wall were calculated for different thicknesses of the brick layer. The optimum brick thickness chosen corresponds to the one that maximally enhance the thermal inertia and thermal resistance. Afterwards, the brick wall was externally insulated with hemp wool, a bio-based insulation material. For an hypothetical lifespan of 20 years, and based on the life cycle cost analysis, annual heating and cooling requirements, optimum insulation thicknesses, energy savings and payback periods were calculated for all wall orientations and considering the six climatic zones of Morocco. It was found that the optimal brick thickness was equal to 0.20 m and the optimal insulation thicknesses vary between 1 and 6 cm for the different climatic zones and the different wall orientations. Moreover, a comparison with the minimum technical specifications fixed by the Moroccan thermal regulation showed that our results allow the reduction of annual heating and cooling requirements by a minimum percentage of 56% for the city of Ifrane, and a maximum percentage of 79% for the city of Marrakech. Finally, annual greenhouse gas (GHG) emissions were also calculated and it was found that they can be decreased, with the use of optimum thicknesses of hemp wool, by a minimum of 32% for the city of Ifrane and a maximum of 75% for the city of Errachidia.