All window blinds block some amount of sunlight from entering a room, naturally cooling the space. However, some blinds are more suitable for keeping your home cool during the warmer months than others. Using blinds designed to keep rooms cool can lower your utility bills without expensive materials or upgrades to your home's cooling system.
These blinds are made from small strips of bamboo that are woven tightly together to create a solid mat. The experts at BC Hydro say that blinds made from bamboo perform a good job of blocking heat entering your windows, whether they are installed inside the window or on the exterior of the home. The weave will let in some light while blocking up to 65 percent of the heat that would normally come in through a window. Install them as close to the window as possible, and plan for an inch or two of extra material on either side of the window to increase their efficiency.
While all light colored aluminum blinds will reflect some amount of heat, there are blinds available with one side left unfinished to expose the shininess of aluminum. According to the Earth Easy website, installing these blinds in a window with the more reflective side out works well to prevent heat from flowing into the room. Aluminum blinds are also tough and hold up to years of direct sunlight without fading or damage. These blinds make an inexpensive alternative to more expensive double-sided blackout curtains or ultraviolet (UV) blocking films.
If you aren't concerned about letting light in through the windows during the hottest part of the day, choose a set of vinyl roller blinds. These blinds are made from single sheets of vinyl and may be covered in fabric for a more elegant look says Blinds.com. Their lack of slats or holes means light and heat won't leak through as long as they're closed. Cloth roller blinds can also be purchased that are made with solar shading fabric, which filters light through its looser weave while still blocking out heat. Vinyl blackout blinds made from thick material should offer the most heat protection, but they may be prone to fading after constant exposure to direct sunlight.
Blinds with horizontal slats, made of any material, will offer some cooling effect to a room if they are positioned correctly when direct sunlight hits the window they are installed on. The BC Hydro website says that the inside edge of each slat should be tilted upward to trap the maximum amount of heat, which will let some amount of light into the room as well. The energy saving effects of the most efficient blinds will be useless if the room must use extra electricity for lighting because it has been darkened too much by the window treatments.