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I've used bubble wrap on windows for
This is a simple technique for insulating windows with bubble wrap packing material. Bubble wrap is often used to insulate greenhouse windows in the winter, but it also seems to work fine for windows in the house. You can use it with or without regular or insulating window shades. It also works for windows of irregular shape, which can be difficult to find insulating shades for.
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The view through the bubble wrapped window is fuzzy, so don't use it on windows where you need a clear view. But, it does let plenty of light through.
Suggestion from Pat:
"Bubble wrap small bubble and large can be had for free by contacting furniture retailers or rental shops. They throw it away by the tons!"
I've heard the same thing for places that sell canoes.
I like the medium to large size bubbles. The larger ones appear (from surface temperature measurements) to insulate a little better, and you still get a nice artistic effect looking out of them. The small bubble warp totally obscures the view, but you still get light.
Cut the bubble wrap to the size of
the window pane with scissors.
Spray a film of water on the window using a spray bottle.
Apply the bubble wrap while the window is still wet and press it into place.
The bubble side goes toward the glass.
To remove the bubble wrap, just pull it off starting from a corner. You can save it and use it for several years. It does not leave a mess or stains on the window glass.
If you have trouble with the bubble wrap separating from the window when the film dries, you can try adding a little Glycerin to the water, but this probably won't be necessary.
The wrap can be installed in the fall, and removed in the spring. Judging by how mine looks after a year, it may last quite a while.
When you take the bubble wrap down, put a small number in on the upper right corner of each piece of bubble wrap, and write down which window that number goes with on a piece of paper. Save the paper for the installation next fall. This tells you instantly where each sheet goes, and which way its oriented.
The bubble wrap that I used is from Charlie's Greenhouse in Seattle. They claim that it is made for greenhouse service, and will stand up to the sun longer. I suspect that ordinary packing bubble wrap may do about as well (someone could do a test, and let us know). When buying bubble wrap, look for a company that specializes in packing materials. Places like UPS will sell you bubble wrap, but the prices are high.
(2/27/07 -- see note below on reported bubble wrap life)
Click pictures to enlarge:
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Here are the application instructions that Charlie's Greenhouse provided.
I thought it might be worth a try to see if two layers of bubble wrap might be used.
This may be going a bit far, but it does seem to work.
I applied a 2nd layer of bubble wrap
over the first layer in exactly the same way as the first layer was applied to
the window glass. That is, spray the first layer of bubble wrap with water
mist, and while its still wet apply the 2nd layer of bubble wrap to it and
smooth it out.
For both layers, the bubble side face the glass.
It has been a couple days since I did this, and it is staying in place OK -- not sure if it will stay up with the added weight in the long term or not.
The two layers of bubble wrap fuzzy the view a bit more than one layer, but it still seems to transmit quite a bit of light.
The surface temperature on the 2nd layer is higher than the surface temperature on the first layer, so it is adding some insulation value.
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View through single and doubled bubble wrap.
Blue tape is to take temperature readings on with the IR thermometer.
The bubble wrap has a short payback in cold climates. About 2 months for single glazed windows, and half a heating season for double glazed widows. Details on payback:
For an 7000 deg-day climate (northern US), and single glazed windows, the bubble wrap increases the R value from about R1 to about R2. This cuts the heat loss from the window in half.
Heat losses with and without bubble wrap for 1 sqft of window are:
Heat loss w/o wrap = (7000 deg-day)(1 ft^2) (24 hr/day) / (1 ft^2-F/BTU) = 168K BTU per season
Heat loss with wrap = (7000 deg-day)(1 ft^2) (24 hr/day) / (2 ft^2-F/BTU) = 88K BTU per season
If you are heating with natural gas at $1.50 per therm (100 CF) in an 80% efficient furnace, then the saving for 1 sqft of wrap for the season is:
Saving per sqft = ($1.50)(168K - 88K)/(100K*0.8) = $1.65 per season per sqft of window
The bubble wrap cost about $0.30 per sqft, so the payback period is about 2 months -- not to bad!
If you repeat the numbers above for double glazed windows, the saving is $0.60 per sqft per season, and the payback period is a about one half heating season.
If you use a more expensive fuel like propane, fuel oil, or electricity, the savings will be correspondingly more.
Here is my Rough Performance Test
Some interesting work done by students at LIU on insulation value of packing materials. Probably not exactly applicable to windows, but interesting.
Doug reports that bubble wrap that he installed in 1999 has about had it. He thinks the life is around 5 to 7 years. In his application, the bubble wrap stays up year round.
He reports that at the end of its life, it tends to stick to the glass, so replacing it before this happens might save some cleanup work.
The bubble wrap he is using was intended for packaging, so this still leaves open the question of whether the bubble wrap intended for greenhouses will last longer. The greenhouse bubble wrap we installed is on its third winter, and is still doing fine.
2/27/07, 4/28/07, 9/4/07, Nov 18, 2007
