Bubble Wrap Window Insulation

I’ve used bubble wrap on windows for two three+ years now, and I’m amazed how quick and easy it is.  This year, we are even covering the windows in the guest room — we just take the bubble wrap down when guests come, and put it back up when they leave — 15 seconds a window.

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.

Its been five years since I put this page up, and I’ve heard from MANY people who are quite happy with using bubble wrap for window insulation.

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.

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.  Most people seem to prefer the large bubble version.

Installation

• 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.

A few small pieces of double back tape can be helpful on really stubborn windows.

The bubblewrap 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.

Some places to get bubble wrap:

– Save up bubble wrap packing material that you and friends receive

 

– Check places that sell larger items like canoes or furniture — bubble wrap is often used for packing these.

 

– Check for wholesale suppliers of packing material in your area — these places will often sell a roll to the public.

 

– Here is one potential online source: http://www.uboxes.com (I’ve not actually tried them, but looks OK)

 

– As a last resort, places like the UPS store have it, but the prices are usually high.

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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.

(2/27/07 —   see note below on reported bubble wrap life)

Installation:

Click pictures to enlarge:

Spray water on glass with bubble side toward glass

Smooth bubble wrap out so that water contact holds it in place.

Double Bubble (added Nov 15, 2007)

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.

Click on images to enlarge.

View through single and doubled bubble wrap.
Blue tape is to take temperature readings on with the IR thermometer.

Payoff

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 too 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.

Performance:

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.

Bubble Wrap Life:

Doug reports that bubble wrap that he installed 6 years ago 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.

Source: www.builditsolar.com