Window energy efficiency in Argentina - Determining factors and energy savings strategies

Abstract

In various regions in the world, including Argentina, low-performance windows are massively sold, which means that windows energy saving potential is high. Windows energy efficiency depends on thermal indices (U-factor, SHGC) but also on climate and building characteristics. In order to identify the most influential factors and to explore energy savings strategies for the climatic and technological context of Argentina, a parametric study based on detailed building simulations was conducted using EnergyPlus. The analyzed parameters were window type, leakage rate, location, building geometry, window-to-wall ratio (WWR), orientation and building envelope materiality and exposure. The results indicate that window type is one of the most determining factors, followed by location, orientation and building envelope characteristics. In the most populous locations of Argentina, characterized by mild winters and high solar irradiation levels, windows mainly impact on buildings cooling demand. In consequence, the most energy efficient windows are generally not the more insulated but the ones with low SHGC, which shows the importance of shading devices. In addition, it was found that an adequate architectural design (as regards WWR and windows orientation) may produce substantial energy savings, offering alternative strategies to expensive high-performance window technologies.