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Anyone have experience with sun blocking window films?

Posted by dominogold (My Page) on
Sat, Jul 29, 06 at 2:04

We built a house 2 years ago not realzing the economy was about to take a dive and go into a recession. As a result we have a house on a corner with no immediate neighbors, sure there are people down the road. We have 15 windows on the back of the house. In retrospect we SHOULD HAVE got the Low-E glass windows. They are Jeld-Wen Norco brand wood clad windows. So without any neighbors and being a new sub there is ZERO shade and I mean ZERO and there won't be for years until someone builds behind us and my trees get bigger.

Our house faces straight east, which means the afternoon/even sun is BRUTAL. I swear the A/C runs from noon to 10pm straight before taking a break no joke. Many days it struggles to keep up.

My wife and I would like to look into some window film to help keep some of the brutal sun beating into the house every day all day. Do they actually work? Does anyone have experience with this? About how much are they? Is this a DIY job? Any tips would be greatly appreciated.

I did find this link is there other brands I should consider?

http://solutions.3m.com/wps/portal/3M/en_US/WF/3MWindowFilms/Solutions/Residential/

Thanks


Follow-Up Postings:

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RE: Anyone have experience with sun blocking window films?

I recently did a lot of research on this and realize this is a very complicated issue. Here is what I can add.

1. The heat you feel from the windows is the infrared radiation from the sun. Clear insulated glass blocks about 50% which in reality, isn't a lot. Low-E adds another 30% which translates to about 65% but I found you still have tremendous heat gain. Low-E,however, is also good in the winter since it will reflect the heat back into the room much better than regular glass.

2. As for films, you get what you pay for. The dilemna here is balancing price with tint. Almost all films will block 98% UV (which fades all fabrics). There are plenty of what I will call "relatively" inexpensive films that are usually applied to commercial buildings. They are dark green or tan, make viewing much less pleasing and in certain conditions (lower light) can reflect like mirror which will drive some people crazy. These run about $4-5 per sq. foot installed but can block up to 75%. The really nice option is very very pricey. There are two films on the market (one is a company v-kool and the other is a Deutch manufacturer I'd have to find) make films that block 50-70% of the infrared radiation with much less tinting. These run about $15/foot installed. Do the math and you can easily several thousand dollars doing 12-15 windows. I will warn you that a 50% block sounds good, but when you hold up a film to your face this is still a lot of heat coming through.

Take clear insulated glass. Starts off blocking 50%. Add a 50% film and you now reduce the heat by 75%. I found that the higher blocking films made much more of a difference, but the cost didn't pay.

One option is to buy shades that allow light through but block the UV and IR radiation. You have to put these down in the afternoon (can put a timer on electric ones).

Another point: Films are very effective for blocking summer heat gain but do not help with the winter problem of a cold window. Only shades (by far most effective) and low-e glass work here.

The last option to consider is an awning. Depending on the angle of your house and height of windows, you may not need that large an awning over each window. These will solve the heat problem.

I don't know where you live, but I am in Boston where the heat gain is a major issue for 4-6 weeks. With that, there are probably 15 bad days. It's hard to justify the expense in reality, but the a/c will work a lot better. It will be almost impossible to keep any room cool with a standard a/c system if it is drenched in sun. They are not designed to work on the hottest and sunniest days. If so, the system would be way oversized.

FYI- Regular screens (Anderson or Marvin) actually block another 50% of the infrared heat. There is a neat device you can purchase which measures BTUs/sq. foot which correlates with the amount of infrared getting through. It is sold by Dodge Industries, Houston, Texas for about $80. I found it very helpful to use and compare different films, shades, screens, etc.

Good luck.

Paul


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RE: Anyone have experience with sun blocking window films?

Sorry to hijack this thread, but by "shades" did you mean cellular shades?

And have you researched llumar or vista films?

Thanks!


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RE: Anyone have experience with sun blocking window films?

Redwood you've done a lot of research it looks like. Your missing some very important information though. Most manufacturers have windows that are made for different climates of our Nation. If you look at any "Energy Star" label it will have the different climates shown on a little map of the US. Depending on the zone your in will determine the low-emitance (low-e) coating that will be applied to your glass. There are three coatings that will determine the heat allowed to enter past your glass. The Solar Heat Gain Coefficient (SHGC) tells you how well the product blocks heat caused by sunlight. The lower the SHGC, the less solar heat the window lets in.

High Solar Gain Low-E - These coatings allow as much heat from the sun to enter the house as clear glass. High solar gain coatings offer the greatest energy savings in regions with cool summers and very cold winters. Northern Climate Zone

Moderate Solar Gain Low-E - These coatings screen a portion of the sun's heat, keeping the home cooler in summer but admitting a good amount of solar heat in winter. Moderate solar gain Low-E coatings offer the greatest energy savings in regions with moderately hot summers and cold winters. Central Climate Zone

Low Solar Gain Low-E - These coatings screen the most heat from the sun. Low solar gain Low-E coatings offer the greatest energy savings in regions with very hot summers and either cold or mild winters (the ENERGY STAR South/Central and Southern Climate Zones). By blocking ultraviolet radiation, these coatings also reduce fading of furniture, floor coverings, artwork, and window treatments. Southern Climate Zone

You must also consider the gasses & spacers used in the Insulated Glass Unit (IGU). The gases & spacers will add even more protection to the inside of your home. Make sure you have windows that match your climate zone before you buy them.

You must also check and see if your window manufacturer will allow any films to be applied to your window. In most cases any after market films will void any warranty you have on any window. On a personal note I would recommend you contact the window supplier and find out the cost of glass replacement with lo/e. You can replace the glass only on each window for a reasonable price in most cases. I'd also go after the builder if they still exist in any way. They're cost cutting tactics used to save them money is an extreme burden or hardship on you and your family. You may also want to check your states building code and find out if lo/e glass is mandatory. If so, you can go after the supplier to make the corrections. They should have known better before they ordered any windows. Hopefully some of this will get you resolution. Good Luck!!!


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RE: Anyone have experience with sun blocking window films?

I diy'd 70% heat rejection film from homeDepop - gilafilms.com . Certainly can see where someone might put a score or scratch a line on the glass cutting in the film. Which would think would make a weak spot on that glass.

That aside,,, Its Great Stuff. Wow'd me.

Not at all like 100% mirror bronze film I put on in the 80's which got hot on the film surface making me wonder if radiated heat might be more than the rejection of sun light. This stuff stays cool to the touch & up close face touchy/feely. Not a wiff of heat.

Think about $35 for 3'x 25' roll & bout $40 for four foot wide.


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RE: Anyone have experience with sun blocking window films?

mikie,

On my llumar film samples it says nothing about heat rejection. Is that the same thing as solar absorption
or solar energy rejected?

Thanks!


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RE: Anyone have experience with sun blocking window films?

Heck if i know.. Heat Absorbtion ,, Sounds like vynal film? - to me heat absorbtion sounds like the film is going to get hot , which means its going to radiate that absorbed heat into the room. heh, some radiates away on the outside of the window too.

If you dig through the gilafilms.com you'll find all their specs - I just now Looked under Support and there is a link to their way of telling specs.

I was mostly interested in the true SHGC (.22) and Light transmission - I did want somewhat darkening , that I could live with. This is darkening just about the right levels here. Truely is amazing to me how well this gila film really does work with the heat.

Initially, Given the choice I would have gladly bought 3m's heat rejection film in the extra thick version for the proported more shatter resistance even though its actually probably too dark(about 12-15% transmission), but 3m isnt available to the diy'r - 3m is missing the boat and doing the consumer screw u and your hurricane. Their installers dont want to sell it for diy.
I probably will never buy another 3m product after trying to buy some film. Don't think I'd trust any of those guys in my home now, even if it was dirt cheap.


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RE: Anyone have experience with sun blocking window films?

If you really want to diminish the radiant heat entering your window, you can block the window completely from the outside. (What I'm talking about here is great if you don't care what the windows look like from the outside and if you don't want see out of the windows for a few months.) Last year I took several large size peices of thick cardboard, painted them white, and slipped them between the window and the screen. This blocked/reflected 100% of all sunlight and radiat heat and it was inexpensive. The cardboard held up through the three months of the most intense heat of the Mississippi summer, and my AC was grateful. If you block the light and heat from even touching the panes of your windows, it doesn't get inside. Sounds goofy? Well, it is. But it works. And it's cheap.


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