Energy Performances of a Passive Building in Marrakech: Parametric Study

Abstract

This paper deals with the modeling of a villa type house located in the Marrakech (Morocco) suburb. The house is constituted of two floors and was designed to be energy efficient by integrating some passive techniques: overhangs, an Earth-to-Air Heat Exchanger (EAHX), thermal insulation of the roof and external walls. Most of these systems are unusual in Marrakech buildings; thus the objective of this work is to study their effects on the house cooling and heating loads. The modeling of the house is a multi-zone one and it was carried out during one year. The effects of the passive systems on air temperature in the building, as well as on its cooling/heating load, are analyzed through the modeling of 5 cases. The first case is the real house and the others correspond to the lack of one of the system (i.e. the overhang along the south facade in the second floor, thermal insulation of the roof and thermal insulation of external walls), the fifth case correspond to the lack of all the systems (“standard house”). The results show that some of these systems reduce the maximum temperature, while some others act only on the minimum temperature by increasing it. The first systems reduce the cooling load and are very efficient in summer (this is the case, especially, of the thermal insulation of the roof). The other systems reduce the heating load and have a small effect on the cooling load. It should be mentioned that the heating load of the real house is negligible compared to the cooling one. One of the interesting results is that, corresponding to the effect of thermal insulation of external walls. This insulation has a small beneficial effect on the heating load while it increases the cooling load.