Evaluating the effects of passive cooling and heating techniques on building energy consumption in Kandahar using CLTD method

Abstract

Insulation plays a very important rule in thermal comport. Recently different materials are used as insulation in building for heat prevention. Years before, the buildings were made of very thick muddy walls and roofs to eliminate the extreme effects of summer and winter. In contrast, today’s buildings are built from burnt bricks and concrete which require too much energy for insuring thermal comfort. To insure thermal comfort without consuming too much energy in today’s built building, four effective heating and cooling techniques were assessed in this paper on the computer based model of media operational center building located in Kandahar University. The current structure (wall thickness one brick and single glaze window with no overhang) of the building was kept as the first case (reference case), which requires 40,307 kWh energy for cooling and heating the building per year. In the second case, 5 cm cavity was added to the walls. In the third case cavity was replaced by 5 cm insulation. In addition to that, single glazed windows were replaced by double glazed windows in the fourth case and overhangs were added to windows in the fifth case. By adding the mentioned four techniques to the building structure, the heating and cooling annual energy consumptions of the building reduced to 38,435 kWh, 35,886 kWh, 33,948 kWh and 33,211 kWh respectively. Which shows 4.65%, 11%, 15.78% and 17.6% reduction of energy, respectively. The results show that the application of mentioned techniques in Kandahar city will have a positive effect on the economy and thermal comfort of people.