Building activities in industrial nations constitute to at least 40% of a country’s energy requirements, with windows and framing products accounting for a significant share of this demand.
Studies by the US Department of Energy recently concluded that fenestration for residential and commercial structures represent a major part of any country’s total energy requirements. It also found that the adoption of energy-efficient fenestration products could result in a significantly lower percentage of energy consumption. This explains the modern tendency to use double-glazed windows in an attempt to save energy.
South Africa has also adopted this strategy. Ramsey Bader, a spokesperson for Edgetech, says: “Windows can account for 20% of the total energy consumption of a typical building in the US. In South Africa, windows will with no doubt account for much more, due to the existing fenestration practices that leave much to be desired in terms of energy-efficiency.” He says local legislation has recently been implemented to ensure that thermally efficient practices are followed.
“In the future, the optimal window will combine laminated, solar-reflective, heat-strengthened or laminated solar-reflective tempered glass in an insulating glass unit and efficient frame design. Such components can double the window’s thermal performance, compared to the base case of a single-glazed clear-glass window. Globally we are seeing a move towards properly manufactured windows with IG units to reduce the heating and cooling energy needs. These units also ensure inside temperature stability against outside temperature variations and provide thermal and acoustic performance that far exceeds the performance of laminated glass by itself,” Bader concludes.
The most important factors when building quality IG units are:
1. IG unit design (single seal vs. dual seal and spacer system selection).
2. Desiccant volume and effectiveness.
3. Sealant selection, application and the volume used.
5. Proper glazing practice.