Adapting a Car Sun Shade for a Home Window





Introduction: Adapting a Car Sun Shade for a Home Window

South-facing windows are great during the winter, but can be unbearable during a summer heat wave. Closing the blinds or curtains helps, but the heat (infrared) still passes through the window which is why the blinds feel warm to the touch. Window films are better at blocking or reflecting the rays, but they can obscure the view at other times of the day and may need to be removed during the winter.

This Instructable shows you how to repurpose a car sun shade for an "as needed" window heat shield, even for windows that open vertically.

Step 1: Materials

1. Car Sun Shade (Fan-Folding style is better). Larger ones are approximately 60 inches x 30 inches (150cm x 75cm).

2. Clips (i.e., Binder clips, Chip clips, or even Magnets) - Optional depending on window and sun shade

3. Support Rods (i.e., Yardsticks, Garden Stakes) - For vertical windows

Step 2: Horizontal Windows

If you're lucky, all you need to do is place the sun shade in your window and close the blinds. For ventilation, you can open the window slightly and fold back the sun shade as needed.

CAUTION: It is recommended that you install the sun shade FLAT. This not only prevents the sun's rays from getting past the window, but more importantly, fanfolding may tend to concentrate the reflected rays and create a solar cooker effect (not desirable unless you plan to simultaneously cook some hotdogs)!

Step 3: Vertical Windows

For vertical windows you'll need support rods and clips. As noted earlier, install the sun shade flat. For ventilation, you can open the window slightly and fold up the sun shade as needed.

Step 4: Self-Expanding Sun Shades

Self-expanding sun shades can also be used, but the one-piece style tends to limit adjustability. With a two-piece style, hold the halves in place with clips or even magnets.

Step 5: My Setup

For me, this window faces the backyard so I can leave the sun shade in place without being an eyesore to the neighbors. In late evening I fold back the sun shade and use the window fan for extra ventilation. This arrangement keeps the room bearable during summer heat waves.

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    9 Discussions

    So Cal western exposed windows are brutal when the sun goes down. Heat and glare. Nothing to see through my windows so I bought the car shade mat'l at do It Center by the yard and with just a bead of silicon glue around the edges I tacked the shades on the outside, except second floor which was too high.

    I wish someone would publish a DIY plan for wooden outside louvers.

    I used aluminum foil on my windows to keep the heat/cold out. I loved it but it made so much condensation that it was dripping and I took it off. Sure kept the room warmer tho. We don't have double pane windows and it gets very cold here. Perfect for a cave dweller like me! Now we need to test the solar cooker made from the foil shade!

    1 reply

    Double pane windows make a huge difference if you can do it. For me, no longer need A/C during summer and no condensation during winter. In the meantime you can try bubble wrap instead of foil during winter as it will allow sunlight in while the air pockets will provide some insulation. It may even create an interesting diffused light pattern (photographers sometimes use bubble wrap to diffuse their flash). Try it out and make an Instructable...

    why not just use reflectix on the windows? I used to put it on our Windows on sunny days to reflect the sun heat back out. You can buy 4 x 25 foot rolls at Home depot and Lowe's in the insulation isles.

    1 reply

    Good suggestion. Car sun shades were the right size for my windows (no cutting), plus the pre-folded design made it easy to fold back for ventilation and was easy to store. The rolls are a great idea if you have many windows, large windows, or non-rectangular ones.

    Excellent. I purchased the foldable shades years ago, and they remain in my basement for an upstairs window. Never completed the project. Your are inspiration.

    1 reply

    Glad to help. I have a few unfinished projects that need inspiration as well..


    11 months ago

    This is a great idea. I live in a hot constantly sunny part of California and have been able to really cut down on heat getting inside by using similar method. Tried blinds, pull down shades and thermal curtains but this the best method yet.

    1 reply