Heat Blocking Curtains




Introduction: Heat Blocking Curtains

About: I'm an engineer. I problem solve all day, problem solve all night. I LOVE learning, and I love teaching what I learn. I want to post more, but time constraints stop me.

Summer is nearing/here, and it's getting hotter in my house. To save electricity with our super expensive A/C, I constructed reflective curtains to block sunlight from warming our house. Think auto windshield. This is super simple and kind of obvious, but it works well.

Step 1: Materials:

2-3 Emergency blankets/foam reflective pads/ windshield blockers*
Roll of 2" wide tape (I used aluminum tape)
Bag of Grommets and crimper
Bag of curtain hangers

*I don't know about in the US - I've had these before in my camp pack as "emergency blankets" for protecting you in the event of shock or if you have to sleep somewhere in the cold. The emergency blankets don't have any backing on them, so maybe you might want to glue some foam/paper/cloth to the back. Super 77 tack is perfect for this.

I'm currently in Japan, and in the 100Yen shops (great places for makers - come to Japan just to stock up for supplies) they have these mats that are meant to be used as picnic mats.

Step 2: Constructing the Curtain

Fold top edge of the curtain over and staple in several locations to hold it in place. This will give more "meat" for the grommet to grip when you crimp it.

Then decide where the curtain will fold and crimp a small grommet into the fold as shown. The grommet should be able to punch thru this - I've crimped grommets thru fabric and it usually cuts a little hole for you. If not, an X-acto blade should clean it up nicely.

- small tip, I made it so that the folds end up rubbing against the window - this makes it slightly annoying to push open the curtain completely; two hands are needed. See if you can fix my mistake on your design. (-:

Step 3: Add Extra Lengths If Necessary

Our windows are bigger than the curtains - I cut up another blanket and turned it into an extender by taping it on.

I taped it in the front using aluminum tape (doesn't make much of a difference, but it looked better on the shiny side) and used normal packing tape to secure the back.

Step 4: Tips and Suggestions

Secure one end to the anchor point so you can slide this easily from one side to the next.

You can make two curtains, one for each side, but I found that this one curtain is easily hideable behind one of the decorative curtains.

Whole project cost:
$4 for blankets
$1 for grommets
$1 for tape

~$6 total

I think this will save a lot off of our summer electricity bill since I can't feel the heat from this window anymore. The wall next to it heating up is another issue, but I don't see how to really fix that.



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    52 Discussions

    Yesterday the sun was very hot and heating up my cabin to unbearable from heat from the NW windows. I had two windshield sun reflectors from Dollar Tree I was going to use for my cars but in a bit of desperation to relieve the heat situation in cabin I used them to cover one of my windows. Amazing difference. These also already have the foam backing on them. A little more time pondering how to make them look more like window coverings for a house to improve their appearance is what needs done now. Maybe a lace sheer or lace table cloth to cover them? Something cheap and attractive. Will also reverse the car shades for the cold winter months to keep heat inside. Great Instructable! It's been on here for years and still getting comments!

    Thank you so much for this idea. My apartment gets the morning sun and it also gets really hot in the summer and my portable air conditioner can't seem to keep up with the heat. This is going help so much in my living room & bedroom. I put a thick painters canvas drop cloth over the window that helps a little but your idea is going to save the day!!

    i did this a few years ago with mylar stapled to regular curtains . Yes , hella ghettoish . No gf tho so ... .Alas it was too loud when turning on the baseboard heaters just the convection would make then rustle . Plus I had to press them against the wall to allow the baseboard heat to rise inside apartment instead of between curtain and cold window .
    Want to now make horizontally pleated double bubblewrap foil blinds next .

    I'm thinking of turning the bed of my truck into a "mini camper," so I think this would be a superb idea for covering up the topper's windows during the summer (they could even be reversed to keep warmth in during the winter!). Many thanks for the idea!

    i wonder if a mirror finsh tow way glass film and it can reflect off heat as weel

    idk how if this will work for heat but it works well for cold a good idea as tacky as it may be is to put saran wrap infront of the windo not tuching

    Draping some emergency blankets across the windows with clothes pins or office tape, brings quick and cheap relief. I have used it for years. The downside is that all women hate it. No big wonder, there were never any women the Apollo lunar lander.

    Can paint your glass with insulating nano paint. Expensive, but think of the energy savings! One drawback, it does distort viewing, best for frosted glass. Can also use the nano paint on interior/exterior walls. Exterior plastic film on glass won't work here--frequent sandstorms scratch glass, much less plastic. Have to use a variety of sun-insulating methods in combination; i.e., thermo-curtains, nano-paint, etc.

    sweet! i would love to make my house all shiny cept community laws keep me from doing so. i can't sun dry my clothes or install solar panels! basically i can't do anything "green" cept if no one can sees it.

    5 replies

    I think now (as of 2010) you can fight those community issues and win. Especially due to the fact that everyone is going green. They used to have a no laundry drying line law in my area, but they can't enforce it anymore due to more and more people saving the earth and telling the "neighbourhood anal retentive committee" (you know who they are... they go around measuring everyone's lawn height) where exactly they can stick it!

    Can you put on tinted window film? There's removable types so it can be taken down if you need more light in a cold winter climate. That's what I've done on my west-facing windows, and it makes a big difference in how hot the rooms get in the afternoon.

    yep. Spray clean window with soapy water, put the film on, and use the squegee to work the bubbles out to the edges. I got mine at a big-box home improvement store, it came in a nice little kit with a small spray bottle and squegee included. I think it was in the section near the curtains & blinds. The box might say "RV window film" but I ignored that. Glass is glass.

    I think this would be best if you were able to put the blanket or some type of shutter on the outside of your window, as the less light you let reach the window, the less heat you're going to have inside. The same can be done with UV windshield protectors, because once the light makes it's way through, the heat's already inside. But if you get one of those large accordion ones with straps, you can avoid a whole lot of heat altogether.

    1 reply

    If you put something outside, you have to make it weatherproof. In my case, from the 3rd floor, it's a bit difficult to attach something to the outside.

    I was living in the apartment, so I didn't want to spend a lot of money on something that I eventually had to throw away - this was the cheap way. Besides, the windows were textured, so the film wouldn't attach to the glass.

    That might work, good luck with that! Again, i just used trial and error to see if it would work. Thanks for the comment