Energy ratings are currently being used in a number of countries to assist in the selection of windows and doors based on energy performance. Developed for simple comparison purposes, these rating numbers do not take into account window removable attachments such as insect screens that are, nevertheless, widely used. Research was carried out to assess the effect of insect screens on the heat gains and losses of windows. The work reported in this paper deals with the effect of one screen type on the performance of a base-case, double-glazed window. Using an indoor solar simulator facility, measurements of the window solar heat gain coefficient (SHGC) and U value were made for different screen attachment configurations and climatic conditions. Results with the sample window tested indicate that insect screens placed on the outdoor side can reduce its SHGC by 46% with only a 7% reduction in its U value (0.19 W/m ² · °C), and that insect screens placed on the indoor side can reduce its SHGC by 15% while reducing its U value by 14% (0.38 W/m ² · °C).

Units: SI