Shrink Film Window Insulation

miserlou

Hello,

With heating costs on the rise, I wanted to do some insulation around my windows using those plastic films that you tape in place then use a blow dryer to shrink out the wrinkles. My friend said he saw a big difference after he did this to his house.

My question is, how important is air gap between the film and the window? I ask because there is not a convenient place to apply the film sheet. My windows are all recessed into the wall. If I tape along the wall, I'll get a nice pocket of air between the window and the film, but I'm afraid that the tape will not stick very securely (b/c the wall has a pebble textureA), and I'll also lose use of the window ledge and blinds, since both would be behind the film. (though the instructions suggest cutting a small hole in the film and threading the blind drawstring through the hole). Also, I just think it's kind of ugly.

My other option is to tape along the metal frame of the window itself. This has appeal because it is unobtrusive (being behind the blinds, and the tape sticks well to the metal, so I can get a good seal. The problem is, the air gap between the sheet and window would be much smaller--between 2in and 1/4in at different points around the window, at some points even touching the window. With such a small gap, will I still get good insulating value, due to the basically air-tight seal of the sheet?

Thanks for your help.

jmic

Don't be a Miser, Miser. Go out and spend a couple of bucks and try it, then you can tell us.

slickshift

It becomes more effective if there is an air gap
It does not have to be a large one to work, small ones work well too
It would not be effective if the plastic sat on the glass for most of the window

IHI

I would'nt expect it to "insulate" so to speak, the plastic is just too thin and does not have any "performance" in itself so weather it's touching the glass or 2" away the main purpose is to stop air infiltration first and foremost with heating "trapped air" second. You'll notice bigger gains by just stopping the incoming air around there older units than you will over any thermo gains.

The whole process is a PITA, but well worth it to help keep your heating dollars working effeicently, just save the pennies for new windows when you can swing it. They're one of the least favorite homeowner purchases cuz "they're just windows", LOL, but I promise once your done you'll be singing praise along with everybody that's done it with quality windows and wish you'd have done it sooner

good luck, have fun
Josh

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johnwoods

Hi!
Just tried this on my windows. I have in a ten year old house and the double glazed unit are failing.
I seem to have the heating on permanently.
I heard about the Window Film from a friend who pointed me to
http://www.window-insulation.co.uk
I purchase 3 packs and i have not looked back.
Best investment ever!
My next door neighbour has done the same because the windows they install nowadays are useless (hardwood).
I hardly put the heating on and the house is permanently warm.
It definitely works- no doubt about it.

Cheers
Peter

nap

deleted- realized the guy before me posted to a 1 1/2 year old thread.

johnwoods

OOPS!!
cant you tell i am new to forums!!

oberon

Old, but appropriate for this time of year.

Joppy

Hi All,
I realize this is old, but I have been installing the window film for a few years. The windows in my home are new, but I have almost an entire wall of them for passive solar heat gains in the winter. The extra layer of plastic film probably reduces gains slightly during the day, but it really holds in the heat at night.

Responding to the distance from window question... there is a balance between the 'dead air' insulation benefits, and the tendency for convection to occur inside the dead air. A gap of about 1 - 2'' seems to be ideal in my installation. This minimizes convection currents in the gap.

I hope this helps,

Joppy

batwomen

Hi I also have recessed windows and the gap is about 4 inches. Is the gap too much if I end up going flush with wall. In addition will there still be condensation and do I remove it before applying the film. This is my first time and would appreciate any advice. Carolyn

Joppy

Hi Carolyn,

A four inch gap is not ideal, but it will still be way better than before if your windows were drafty. When I install the film, I dry the window thoroughly using a cloth and then hair dryer. There shouldn't be any condensation between the film and window, but on real cold nights there might be condensation on the film depending on indoor humidity.

The two sided adhesive will probably peel paint or other finishings, so be carefull if applying to the wall. My windows are recessed, but have about 1/2'' of vinyl surround and it is enough to apply the film.

Joppy