Which Heat Blocking Window Treatments Are the Best?
Montana summers can surprise people who haven’t spent one here. Afternoons in the Bitterroot Valley get hot, and west- or south-facing windows can turn a comfortable room into a difficult one by mid-afternoon. If you’ve noticed rooms heating up more than they should, your windows are almost certainly part of the problem — and the right window treatments can make a real difference.
Here’s a look at the most effective options for heat blocking window treatments.
Why Windows Let in Heat
Glass is not an insulator. During the summer, direct sunlight hits the glass, warms it, and radiates heat into the room. Even low-E glass, which is designed to limit heat transfer, doesn’t eliminate the problem entirely. The amount of heat coming in depends on the window’s orientation (south- and west-facing windows get the most direct afternoon sun), the type of glass, and how close the window treatments are to the glass.
The closer a treatment sits to the glass, the more effectively it intercepts heat before it enters the room.
Cellular Shades: Built for Heat Blocking
Honeycomb or cellular shades are among the best blinds to keep heat out for a straightforward reason: the honeycomb cell structure traps air between the window and the room. That trapped air acts as a buffer, slowing heat transfer in both directions — useful in summer for blocking incoming heat, and in winter for keeping warmth from escaping.
Hunter Douglas Duette® Cellular Shades are available in single-cell and double-cell configurations. Double-cell (two layers of honeycomb) provides stronger insulation. For rooms that see significant sun exposure, this is one of the most practical and proven options. Graber® Cellular Shades offer similar performance, also available in a range of opacities, depending on how much light control you want alongside the heat management.
Heat Blocking Window Shades: The Solar Shade Option
Solar shades are designed specifically to reduce solar heat gain while maintaining visibility to the outside. They work by filtering UV rays and diffusing direct sunlight rather than blocking it entirely. The material has an openness factor — typically anywhere from 1% to 14% — that determines how much of the view is preserved. A lower openness factor means more UV and heat blocking; a higher one means a more open feel with less filtration.
Heat blocking window shades in the solar category are a strong choice for rooms where the view matters. Living room and kitchen windows facing the afternoon sun are a common application. You get meaningful solar control without the room feeling closed off.
Alta® solar shades are a popular option in our lineup. They hold up well, come in a range of openness factors, and work well in the Montana environment, where UV levels at elevation can be higher than people expect.
And if you're looking for extra solar protection for your home's exterior, you might consider exterior shades.
Heat Blocking Blinds: Roller Shades with Blackout Fabric
For rooms where heat blocking and full light blocking are both priorities — a west-facing bedroom, for example — a blackout roller shade handles both jobs. The dense fabric blocks direct sunlight entirely, so there is no solar heat transfer through the material itself.
This isn’t the same as a true insulating shade (roller shades don’t create the same air buffer as cellular shades), but they’re effective at blocking direct sunlight from entering the room.
Layering for Maximum Efficiency
Many of our Missoula neighbors love layering their window treatments. It's great for adding some character while also improving the effectiveness of your window fashions. A solar shade close to the glass to intercept most of the heat, paired with a sheer or linen drapery panel on the room side for appearance and additional softening. The solar shade does the functional work; the drapery provides the finished look.
This approach is particularly effective on large picture windows or sliding glass doors where both solar control and aesthetics are important.
Heat Blocking Shades Near Missoula, MT
If you’re dealing with overheated rooms this summer, let the team at The Blind Guy of Missoula help you figure out which solution makes the most sense for your specific windows. Contact us today to get started with your free, in-home consultation.
We're locally owned and operated, based in Missoula, and proud to serve the surrounding Bitterroot Valley area, including Florence, Stevensville, Victor, Hamilton, Philipsburg, St. Ignatius, St. Regis, Superior, Plains, Drummond, and Darby, Montana.
