While tinfoil is a fantastic option I do have a few other solutions. At work, I love to pull out my lab coat and walk my clients through my exciting version of Energy Efficiency Window Treatments 101. Once I start in with the R-values, U-factors, SHGC ratings I’m usually the only one awake in the room so I’ve learned to keep it simple.
1. Heat is attracted to cold; that’s why in the summer the sun shines through your windows turning your house into a greenhouse.
2. In the winter it’s the opposite the window glass creates heat loss because it’s bringing the chill inside.
There are two good solutions:
1. Insulation: Similar to the pink itchy fiberglass in your walls that keep the heat in or out there are blinds that are constructed to create a barrier that either traps the heat or cold. In blind terms, we call it a honeycomb or cellular shaped blind and the more layers the better.
2. Daylighting: Several window treatments diffuse light reducing the glare and improving the intensity of the light. A lot of these window coverings are sheer enough to allow you to enjoy your view through them even when they are lowered.