Cool it now!

April 20, 2009 8:43 AM

Help me control the intense heat radiating through my living room windows! Reflective film? Curtains?

I live in a house. Our primary living area is a wonderful space. The west-facing wall is composed of three 6' tall x 3.5' wide windows. These windows are on the second floor, and they do not open. The sun beats against the windows all afternoon, and when it gets hot outside, it gets ridiculously hot inside. Like hot hot. Africa hot. (Often 85+ degrees). There is no central air conditioning. We have fans and a portable air conditioner. They help keep it reasonable, but I need to address this problem at the source.

Currently, the windows are fitted with custom blinds. They're nice, but they do very little to keep the heat out. What's the best way to keep the heat from radiating through these windows?

1. Heat-control film? Has anyone actually used this stuff? Does it work? Is it actually clear? This seems like a decent option. The main issue with film is that we have a great view, so we don't want to obscure it with tinting, or film that looks bubbly and cracked. It also seems like the film could be a major PITA to put on correctly.

2. Heavy curtains? Would this even work? Or would the heat just come through window and get trapped between the curtain and the window? This seems like it could easier to implement than the window film.

3. ???

We are renting, so no major renovations will be happening. Ideally the solution won't cost more than a couple hundred bucks. But it's becoming a serious quality-of-life issue that I'd like to address before summer really hits.

posted by gnutron to home & garden (19 comments total)

I have used thermal drapery lining in some rooms and found it to make a huge difference (keeps heat out in summer, cold out in winter, blocks sounds and light). However, curtains need to be closed for it to work so I think you should continue exploring the window film option.
posted by Nickel at 8:58 AM on April 20

I'm not a big fan of window film. We had a hard time putting up a single 6'x4' sheet...it's very lightweight and ended up curling back on itself, getting stuck to itself. I think we ruined a good deal of the film we bought this way. Very messy. Such a pain in the butt that we didn't put it up on the adjacent window. I will say, though, that once it was up it didn't look all that bad. Taking it down was a huge pain, too. Others on AskMe have written about having less difficulty, so YMMV.
posted by puritycontrol at 8:58 AM on April 20

Something that can work really well is to get the densest outdoor blinds you can find, usually bamboo, go for the darker colored ones, and those with the smallest amount of space.
Then hang them outside your windows. You'll probably want to lengthen the cord to raise and lower them, so you can do so without at ladder!
You'll find that this creates some shade between the source of the heat (sun) and your house - and that tiny bit can really make a HUGE difference.
Also get a digital thermometer that has a sensor for outside and inside. When the weather turns hot, as soon as the outside temps are within 5 degrees of inside, close up the house (or in the morning before you leave) - tight. Pull all the blinds, close the windows, etc. Then, when the temperature outside is cooler than inside (and not before) open up all your windows, doors, etc - and get that cool air inside!
I've done this in a couple of different climates (Southwest -dry, and northwest - damp), and it works well.
posted by dbmcd at 9:02 AM on April 20 [1 favorite]

I have some blackout curtains that do a fantastic job of keeping a SSW facing room cool at the height of summer. They're a thin foam that goes behind the normal curtains, but you could use them as normal curtains because they're cream. In the summer, I don't open the curtains until the afternoon.

Is the heat caused by the sun shining directly in, or by the ambient temperature?
posted by Solomon at 9:05 AM on April 20

I'm leaning towards thermal drapes or blackout curtains at the moment, mainly because it seems like they will be easier to install. I have no problem closing the curtains during the day. The heat is definitely caused by the sun shining directly on the huge windows for hours and hours, although it's much worse when the ambient temp is high (like yesterday in the Bay Area.) Recommendations for stores or websites to buy curtains would be awesome.
posted by gnutron at 9:10 AM on April 20

Any thermal film worth applying will be tinted somewhat -- although they've worked to move the reflectance purely into the IR end of things, the films still end up affecting the view.

Additionally, any film you apply yourself (rather than having a professional company do it) will inevitably have visible imperfections. These may be minor, or irrelevant to your purposes, but they will still occur. I say this as someone who installed his own film, is VERY happy with the results, and who frankly had a pretty easy time on the installation.

So: I am quite in favor of owner-installed films, but I think they're not going to be right for you.

Since this is a rental, you probably cannot install exterior shades without approval from the owner (as you'd need to mount hardware that could penetrate the exterior skin). Nevertheless, you may wish to see if it's allowed -- it couldn't hurt to ask.

If you're not allowed to mount external hardware, then insulating drapes/blinds do work. They will trap a hot air layer between themselves & the window, but then they insulate that area from the rest of the room. There are a number of options here, but the key is to look for insulating items, not just "heavy". Just about any window-shade store will have them.
posted by aramaic at 9:18 AM on April 20

Since this the second floor, heat is building up here in part because it's the high point of your house.

Set up a window fan blowing out on the second floor, open other second-floor windows for ventilation, and control the heat on the first floor, and this area may get much cooler.
posted by zippy at 9:30 AM on April 20

Here's a room-darkening shade with a Mylar reflective back. Short of blocking light outside the window, or window film, it's probably the thing best you can do and will reflect more light outside than metallized curtain material or anything that's translucent. Would run you about $400 plus shipping and tax. You could still add drapes for looks or extra insulation value, but I'd put these up first and see how it works out.
posted by beagle at 9:39 AM on April 20

I'm with dbmcd on this one. If you have something outside the windows that's blocking the sun, it'll be a lot more effective at keeping your room cool than blocking the sun inside your room. It's tricky that this is on the second floor and that the windows don't open, because I'm guessing you don't exactly have easy access to the outside of the windows, but if you can get up there, even relatively minor things might help (like just hanging a normal bed sheet in front of the window.
posted by bjrn at 10:05 AM on April 20

The heat is definitely caused by the sun shining directly on the huge windows for hours and hours, although it's much worse when the ambient temp is high

I know you said you're sure, but are you sure that it's the windows' fault? Could the roof / attic be poorly insulated? Is the ceiling warm to the touch on such days?

What color is the outer face of the existing blinds?
posted by jon1270 at 10:14 AM on April 20

I had those reflective film put on by a professional company. It was under $500 for two large windows (both about 8'x6' with multiple parts and a semi circle arc at the top). They work great (70%+ UV blockage) and look great. I never, ever think about the tint. It looks quite natural, I find. It is similar to good sunglasses, you forget after a while. However, I would do all windows in the room to make the difference difficult to notice.

The company will likely give you a sample (4"x4") to stick to your window to get an idea of what it looks like before you commit. If you are really hyper about the tint, you can get clear coating with less effectiveness (~55% blockage I'm guessing). Our tint was made by duPont and guaranteed by duPont.

Another thing you might think about is that a lot of heat comes from your attic. Make sure there is lots of insulation there and the air barrier between your living space and the attic is fairly tight (you can draft proof the attic access hatch for <>
The tricky thing in your situation is that you are renting. So you wouldn't be smart to add insulation, roof vents or even the reflective coating. At least with the black out curtains you can take them with you when you leave.

If you want to stay there despite the problem, I would ask the landlord to split the costs. I'm sure he/she knows it is a problem but like most business people (well, people in general) doesn't want to spend the money if he/she doesn't have to.

Finally, remember that humidity makes temperatures feel much hotter than they are. So get rid of as much humidity in your apartment as possible. That means getting rid of plants, turning on the hood above the stove when cooking, continue using your portable air conditioner and begin taking short cool showers with the bathroom fan running.
posted by FastGorilla at 10:21 AM on April 20

Correction:

You can draft proof the attic access hatch for less than 10 dollars. Just as important you want to make sure that there is good ventilation above the insulation. The hot air needs to blow out of attic quickly, especially during the night when it is your houses chance to cool down. This is why houses with near flat roofs are bad.
posted by FastGorilla at 10:25 AM on April 20

Cheapie curtain suggestion. Line whatever decorative drapes you have with felt. I've heard that it makes them hang nicely and supposedly has insulating properties. I have not tried this myself yet, but plan to this summer for my southwest facing dining room windows.
posted by sarajane at 10:32 AM on April 20

Great answers, folks. Thanks.

Just a few clarifications: There is no attic. It's a one story house with a flat roof. The house is built against a hill, and the living area sits atop the garage. All the other windows are at ground level, but the living room windows are at a second floor height. These windows are the front of the house, so exterior changes would probably be a no-go as they would drastically alter the appearance.
posted by gnutron at 11:14 AM on April 20

My aunt swears by this 'Warm Windows' stuff for making thermal roman blinds. It's supposed to be useful in the summer as well as the winter for general insulation.
posted by Weighted Companion Cube at 11:31 AM on April 20

Recommendations for stores or websites to buy curtains would be awesome.

I ebay'd "blackout curtains" and got the first ones that came up that were the correct size. Don't buy them with any "fulness" in. Have them so they lie flat against the windowsill.
posted by Solomon at 11:56 AM on April 20

i had much the same problem (mefi)

we bought RV window tint from home depot and applied it ourselves. it was a pain in the ass to do and doesnt look beautiful. i would pay to have someone do it next time. that said, it dropped the temp 7 degrees in my apartment just by itself.
posted by phritosan at 2:35 PM on April 20

Recommendations for stores or websites to buy curtains would be awesome.

I just did a bunch of research on this a few months ago so let me know if you want more information, but you can find thermal lining (which insulates against temperature and sound, but let some light in) and blackout panels (which do everything thermal linings do, but also block all light) on amazon, ebay, Sears, JC Penney, and online fabric stores. I found that buying a bolt of fabric by the yard was much cheaper than buying ready made panels. I can personally recommend Hancock Fabrics which has thermal and blackout lining.

I got the Roclon off white thermal suede, which was $2.95/yard. So instead of paying $60 or more to buy ready made drapery panels, I spent $15 on 5 yards of fabric to cover my 144 inch wide bank of windows. I just cut mine to size and clipped it up behind the sheer curtains I already had up, using the same drapery rings for both. The ends don't fray when cut, so I didn't see the need to sew down the edges, but if you want to sew your Roclon thermal or blackout fabric, whether to hem them to length or attach to the curtains, check out this How To.

Here's a picture of my before and after, and a close up of how I hung it (sideways thanks to imageshack). I found the material to be really thin - which is great because it hands just like normal fabric and not like the thick foam linings from years ago, but also not so great because the teeth in my drapery rings made little holes in it. As you can see, I ended up folding the top of the curtain down over the lining for protection.

No sewing, just cut to size and clip up. It took all of 5 minutes. All for $15. I am extremely happy with my purchase.
posted by Nickel at 3:46 PM on April 20 [2 favorites]

Oops, that last picture should have led here. If only we could edit comments!
posted by Nickel at 3:48 PM on April 20