Heat Load and Solar Gain Prediction for Solid Wall Dwellings Retrofitted with Triple Vacuum Glazing for Selected Window to Wall Area Ratios

In much of the developed world there is a large stock of solid wall dwellings that require intervention to improve their energy performance. Heat loss through the windows of solid wall buildings is one of the factors contributing to high energy consumption for space heating resulting in excessive carbon emissions which lead to climate change. In this paper the heat load and solar gain are analysed for a room in a solid wall dwelling with single, double air filled, triple air filled, double vacuum and triple vacuum glazings at 5.49%, 12.36%, 13.19%, 20.6%, 24.72% and 32.96% window to wall area ratios (WWR's). Simulated results are presented and the influence on energy required for space heating and solar energy gain in winter months (Dec, Jan and Feb) are analysed. The costs for space heating energy are calculated and show that replacing single glazed windows with triple vacuum glazed windows in the simulated room of a solid wall dwelling could save £36.07 annually. Assuming a dwelling consists of 6 simulated rooms, considerable energy and cost savings could be realised. It was also shown that for low heat loss glazings it is possible to significantly increase the window to wall area ratios with little increase in room heat load.