Need to know how to block sunlight heat from windows? Window blinds, shades, and panels all provide DIY window insulation, but also block light. If you want any natural light, or a view, you need something that blocks sunlight heat from windows, but lets the light in. Indow window inserts are the best way to block heat from windows while still seeing the light.

Beth Bryan lives in Alabama and needed a way to block heat from her windows. She wasn’t going to settle for any products that left her in the dark. She wanted natural light in her attic office, but it was also way too hot. “I could roast a chicken in here!” she said before getting an Indow Shade Grade Insert.

one window without an insert shows a thermostat at 91 degrees, one window with an inserts shows a thermostat at 75 degrees: how to block sunlight heat from windows

Beth’s attic office cooled by 16 degrees as soon as she added an Indow Shade Grade insert.


Beth works from home, where her office regularly gets up to 91 degrees. It’s well designed, but the west-facing window was no match for the Alabama summer sun. Her blog, Unskinny Boppy, chronicles her DIY home decorating and the pursuit of comfort. There, she shares how to keep heat out of windows and how once the insert was installed, there was an instant 16 degree temperature difference.

“My attic-turned-office is a nice cool place to work now!” -Beth Bryan


Options for How to Keep Heat Out of Windows

Beth was intent on having access to natural light, but there are other window heat blocker options. More information can be found at the Department of Energy.

Window Blinds & Curtains – Blinds, fully closed are pretty effective at reducing summer heat. They are somewhat difficult to control and will let light in between the slats. Window curtains can reduce heat by 33% if multiple steps are taken: the curtains are medium-colored, have white-plastic backings, and remain closed.

Window Shades – Accordion-like insulated shades that can fold up to the top of your window frame. Usually two layers with air pockets in between to increase insulation. About 20% energy savings. Only insulating in the down, light-blocking position.

Window Film – Film adheres to your window glass and comes with many options: tinted, UV-blocking, Low-e, blackout. Their effectiveness depends on their transparency and orientation – less transparent and west/east-facing windows benefit more. This means, less light and loss of view.

Low-E Windows – Low-emissivity coatings reduce heat transference through windows up to 30% – 50%. If you’re interested in replacing your windows, know that low-e windows cost 10% – 15% and the coating lasts 10 – 15 years.

Window Inserts – Inserts or interior storm windows, block heat and UV-rays while allowing natural light to penetrate. Indow solar window inserts add 20% energy savings on average. They have the added bonus of blocking noise.


How to Insulate Windows from Heat with Window Inserts

man installing window insert for diy window insulation

Indow solar window inserts blend into the surrounding window frame and stay in place with a compression tube frame. They are easy to install and remove and require no mounting hardware, leaving your window frame unharmed.

Indow Shade Grade inserts cost $36 per square foot. That’s $432 for a 3 x 4 foot window. Because they create a tight seal, the window inserts keep heat and hot drafts out, so you will turn the a/c on less. With the 20% avg energy savings our customers get, they find it’s well worth the investment.

Indow Shade Grade Inserts:

  • Reduce solar heat gain by 51% & UV rays by 90%.
  • Use compression tubing to create a tight seal to insulate windows from heat.
  • Provide an air seal that also keeps hot drafts out.
  • Cost $36 per square foot.
  • Can be easily removed without damaging your window frames.

DIY Window Insulation Saved This Home Office

Beth can now work comfortably in her home office, even when it’s 105 degrees outside. As a DIY home decorating, she especially loves the natural light and how she can barely tell the inserts are there.

If you’re still searching for how to block sunlight from windows, see if Indow solar window inserts work for your space. This video takes you through each of our grade types, including Shade Grade, to show their functionality and how they fit in your window.


When it comes to working at a desk, be it from home or in an office, excess noise is an even more common problem than heat. Check out our resource for soundproofing office windows to see if our solution is a fit for your space.

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