Numerical assessment and optimization of a low-energy residential building for Mediterranean and Saharan climates using a pilot project in Algeria

The awareness for energy efficiency in buildings increasingly expands in Algeria, where a legal framework exists for promoting the utilization of regenerative energies. However, models of best practice are still relatively few. As a contribution, this paper reports on a study, which aims at finding out the best design strategies for affordable energy efficient residential buildings. The focus is put on the Mediterranean Algiers and the Saharan Ghardaia. Dynamic energy modelling was carried out using TRNSYS 17 to assess a residential house built as a MED-ENEC pilot project. The simulation is executed at two sequential stages: the reconnaissance stage where the building is compared to a typically non-insulated conventional construction and then the assessment stage, in which the pilot project already designed to low energy standards is investigated in an attempt to increase its energy efficiency further. By means of a parametric study, the most efficient passive design measures for minimizing heating and cooling energy demands were delineated and their dimensioning fixed. The results confirm i) the easiness to save energy in comparison to the local inappropriate conventional building type, and ii) possible additional energy savings in the pilot project, so that almost no heating is required and the cooling visibly further reduced.