Analysis of Behavior of Windows in Terms of Saving Energy in Extreme Cold Weather Climes of Iran

Abstract—It has been recognized that windows, the thermally weakest link in the building fabric, are thermal holes. This paper aims at analyzing the performance of double-glazed windows in terms of total saved heating and cooling loads in the extreme cold weather throughout the year and in different orientations. A four-story building representing the conventional type of residential apartments in Iran for city of Ardabil which is the representative of extreme cold climate was selected for simulation. Four physical properties of U-factor, solar heat gain coefficient (SHGC), visible transmittance (VT) and emissivity along with the orientation were the factors taken into consideration for simulation. It was concluded that in Ardabil, as a heating load dominant city, the merits of utilizing double glazed windows lie in their savings in terms of heating load not cooling load. In fact, using double glazed windows in extreme cold climates imposes extra cooling load on buildings which of course is inconsequential in comparison with the saved heating load.