Block the Heat at the Source
Studies demonstrate that medium-colored draperies with white-plastic backings can reduce heat gains by 33% of the heat generated by insolation. "If you’re up for installing an awning, that’s the best solution of all," according to OUC. Window awnings can reduce solar heat gain in the summer by up to 65 percent on south-facing windows and 77 percent on windows that face the setting sun in the west."
How can inside window treatments only remove 33% of the heat if they perfectly cover the window? This is because the sunlight has to pass through the entire window before it gets reflected or absorbed by the window treatment, meanwhile heating up the glass, the air pocket between glass and drapery and as well as the drapery itself. The heat spreads from there into the room.