Window/draft sealing - how much does it help?

I just ran thru the Canadian Energuide for Houses program. They have a great book called Keeping the Heat in found here http://oee.nrcan.gc.ca/keep_heat_in/introduction.cfm.

The biggest change we felt in running thru our upgrades were when we replaced the basement windows - it wasn't because of the windows, but because we sealed some big leaks in doing so. The humidity went up in the house, and the temp in the basement stayed more constant, 'cause we were no longer allowing outside air to be sucked into the house.

Last week we had the sill plate sealed (spray foam in the joist cavities where wooden mud sill / top plate meet the concrete). Tightened up the basement again, to the point were the new windows we installed, and thought were sealed well were now allowing air in, as they became the new path of least resistance.

All of this, plus the wet sprayed cellulose (wet spray allows for a better air penetration resistance than loose fill - think paper mache) installed in the attic and caulking the attic hatch shut, helps reduce stack effect in our 75 year old 2 storey.

I woundn't necessarily agree with that. Depends on how and where you install them. They both typically would install int he exact same place and would trap the same air volume, its just that the shrink wrap is clearer. Whats most important is that you make sure the plastic has the most airtight seal you can make when you put it in.

I just finished adding plastic to my 15 windows and can feel a major difference - both in drafts and in temp around the windows. And these are good 7 year old peachtree windows too.

Your assumptions about where the plastic is installed is wrong on both counts. Generally, the plastic is installed on the inside of the house. And I'd suggest leaving at least 1" air space between the glass and the plastic. As was stated by other folks above, clearity - being able to see through the window is ussually the most important factor. Use either the shrink or non-shrink. However, if your using regular plastic, say 4-6 mil thick, I think this is way to thick to get a good seal around the window. What is MOST important in the install, is to get a perfect seal all the way around. Trust me, you'll feel the difference if there are any gaps. Lastly, becareful when you shrink the film, not to heat it to much. If it heats up to much, it will pull the 2sided tape off and leave gaps.

Good luck - use the shrink film - get a perfect seal all around, and you'll be very satisfied.

Dave from Maine

Karri.... keep working on your project. it WILL save you money.

Sealing - or stopping the air drafts / air movement is far more important than insulation. It's the first step. When you feel a draft (around a door or window), thats air that is coming into the house. That air has to go somewhere, and what happens is - it finds it way back outside. So in affect, you have cold air coming into the house - that air then heats up to equal the temp in your house - (your paying extra to heat that cold air). and then that air finds ways of getting out of the house (usually, through the attic). That is air you have heated, now leaving the house. I have read where the typical older house has drafts that can equal an entire window being left open.

At $3-$4 a gallon for oil - $30,40,$50 in good shrink sealing plastic will pay for itself hands down.

I can't stress enough - take your time doing the install and get a perfect seal all the way around.

Let us know how your doing

Dave fro Maine

For plastic around the windows:

Plastic sometimes contracts and expands as the outside temperature changes, pulling away from the seal. To reduce the chance of a seal break where the tape holds the plastic, use 2 rows of tape. Think of it as a picture frame around the window and then another picture frame that is an inch wider all the way around. Stretch the plastic tight and try not to use the blow dryer to shrink . . . it can easily be overdone.

All my windows got different applications-depending on whether I have to look out or not. Two windows are brand new-they get a "Foil-Bubble Foil" piece of radiant barrier at night.Have to remember to take down in the mornings- as the sun will surely melt the hardware.The piece just hides behind the chair.These work fantastic and its nice and cozy at night,which I dont have to see out there at night anyways.Those get stored away to use next year. I buy clear plastic shower curtains- its heavy vinyl and clear to see out on the windows that need that.Less exspensive then the shrink wrap. then the others that I dont need to see but want to let in light get the regular plastic.The north side window with no sun gets more foil-bubble foil,and that stays in place all winter.It doesnt take long to do the windows- I do four one day- then another four the next etc., and it pays off. New construction on the addition and every door and around windows are insulated and chalked.Now insulating the cellar presently,-that'll take another month to be done with that,cost- $450, and a one time application-increasing the warmth of the cellar. In April we're gutting our bedroom and crawl space attic to insulate and remodel.We know that the money spent will be worth it.Knocked 2 registers in our bedroom for heat to go up- and thats already proving to be a good choice. We know it'll be warmer for the next heating season and dollars well spent. A pellet stove installed this year,and hope a wood stove in the near future,discontinuing the use of oil. Mulch hay around the windy side of foundation.Self-building solar applications at present, It doesnt matter that the price for oil is low now-don't be lulled into a trance, it will not always be that low- and will climb again guarenteed-and continue to climb when the ecomony bounces back as surely it will. Will we all be ready for that when it does...?

I just ran thru the Canadian Energuide for Houses program. They have a great book called Keeping the Heat in found here http://oee.nrcan.gc.ca/keep_heat_in/introduction.cfm.
Thanks Brent, that's a good basic book and web site on energy conservation.
Ed

karri0n said:

Centrally located Isle Royale in a 2000 Sq ft 250 year old house. Very little, if any insulation in the walls. 3 Bay windows, 26 regular sized windows. Partially insulated attic.

I plan on completely sealing the front door, as it's never used and that front foyer is definitely the worst air leak in the house. You can feel the breeze leaving the house through it.

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Ooooh! Not good. Probably violates building codes, big time. Exit in case of fire?

Has anyone tried the commercial-made interior storm window (from any brand)?? I have an extremely tight house (R 44 walls) that seems to magnify the "bad" performance of the windows. We get alot of condensation on the bottoms of the windows in really cold weather. As a side note, this is one "bad" side effect from having radiant floor heat in an extremely tight/efficient home. There is no place for the moisture to go. We try to run our HRV's but we are not there during the days and sllep at night.

karri0n said:

Plenty of ways out. Plus, a pull on the doorknob will easily remove the tape and plastic from the door.

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Yep. Just so long as it's not nailed or glued or caulked or painted shut, etc. Ever try to open a window that has been painted shut? Without smashing it out? You need a razor knife to do it. And time you wouldn't have in the event of a fire.

I have a downstairs door that leaks some. I seal it with that weather seal tape expressly designed for the job. Just tape over cracks, no plastic sheet. Easy release adhesive type tape. One day in mid- winter, a friend who didn't know better suddenly unlocked and opened that door. It did open, with some repeated effort; also pulled off a lot of trim paint. So the weather seal tape is workable in the event of fire.

We have a lot of windows in our house especially in our living room. We installed double row cellular blinds in these large windows and immediately noticed a difference. I've been considering using the shrink plastic on removable frames in other windows throughout the house. I look forward to hearing about the results of your efforts. Good luck.

I found the shrink film here in bulk:
http://www.mcmaster.com/#1014a43/=aruuq

They call it "shrink-to-fit window covering. This may be cheaper than buyin the kits especially if you don't need the tape.

Semipro said:

I found the shrink film here in bulk:
http://www.mcmaster.com/#1014a43/=aruuq

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Good find- thanks!

Just thought I'd follow-up with a few photos of the frame insert that I built for an opening that leads to a very cold cupola that we rarely enter. I may later buy some Plexiglas to glaze this but for now I'm using the shrink film. I actually burnt through it with my heat gun as I was just finishing up so there is some clear tape covering the hole. I wanted to make sure it worked well before replacing the film. It involves removing about 20 screws and the trim pieces that hold the film in place.

Immediately after installing this thing I could feel distinctly warm air gathering below it.

One photo shows it installed in the opening while looking from below. The 2nd shows it uninstalled and laying on the floor of the cupola.