Are these the plastic film inserts?

-AC_Hacker

No. They are pine frames with plastic on either side with qlon around the edges to create an air tight seal. There is a company in a city about 20 Mi south of me (Springfield) that has a small shop making these things. It's entirely staffed by low income individuals and the unemployed. You can make these things for a lot less yourself though.... but you have to actually do it, which can be a PITA depending on your schedule and level of motivation. I myself swore that I'd have some made by the winter. Oops. No inserts yet. Hopefully next year. All you do it rip #2 pine to make a frame, put a supporting brace in the middle and kerf the perimeter with the table saw for the qlon. Your "pane" can be either that window film (on each side) or something a little more durable. Just make sure it's all air tight. Is it going to perform as well as one of these high tech billionaire windows? Probably not. If you have a small house and are thrifty with everything else How long is it going to take to see a return on the $35,000 windows compared to the $8,000 windows? I did the math when I moved into this house and assuming that I live to be 90 and the cost of energy doesn't rise (yeah right) I would never see a return on replacing the windows which are already installed. The only place I'm going to get 3 pane glass is for two picture windows I have. They are inoperable. I'm going to source 3 pane glass from a glass dealer, not some crazy company like Serious or Thermotech, and frame them in my self using a liberal amount of spray foam. If they were already 2 pane replacement windows I probably wouldn't do it but they are the original single pane jobs so replacement makes sense there. Really all decent casements allow about the same amount of air movement. I've seen this plenty of times with blower door testing. At least enough to convince me. Just replace a couple Sq. Ft. of 2 pane glass with R 40 wall and call it a day. Every foot of glass you can replace with super insulated wall is a point for humanity in my book. I'm fortunate in that the clever 1950's builder who made my house did some clever things like: double drywall on ALL walls, low ceilings and small windows.

Say, S-F...

I was talking to a friend of mine who had a couple of double-low E fixed window in his living room. He got the windows made to fit the spaces he had. He just got the glass, with no frames. He said it wasn't so expensive that way.

Such an idea!

-AC

I considered helping someone with single pane windows replace a broken window before and knew that single pane glass was easy to find. Where do we find a glass company to source triple pane glass from? I'd like to do this because the largest window in my house outside of the patio door(which also needs to be replaced), is the large picture window in the front of the house that has a bad seal and the inside of the pane is dirty from the fog that filled the cavity, condensed, and then dried over and over again. I have a feeling it isn't performing much better than a single pane like that and would like to replace it but it is a big window and would be pricey.

At my mother's house the people who installed her siding and windows couldn't find windows to fit some non-square openings and they managed to get some custom-made glass to fit in the space last fall and that was the first I ever saw that happen and didn't know it was an option until then. I'd imagine labor costs were probably more than the window costs, but DIY changes those cost factors. :)

I have yet to begin looking for such glass. I have a friend who owns a huge framing company who has told me that a "good glass dealer" can get triple pane glass and that they get this kind of thing often. That's about as far as my knowledge goes.

Hi,
You might consider a more or less standard R3, double pane, low-e window coupled with a well designed thermal shade.

We did this one:
Bottom-Up Insulating Shades for Light and Insulation -- Our R8.3 Window

The combination of the multiple layers plus the edge tracks and a good fit along the bottom makes for (I think) about a doubling of the R value up to R6 ish. About $150 for a 36 by 54 ish window -- but since you would probably have some kind of shades anyway, its only the increment over a "regular" shade that should be charged to the energy saving.

We liked the results so much on this one window that we did all the windows along the front of the house and our big kitchen window with the same kind of bottom up/top down shades with energy tracks.

We like the bottom-up/top-down in that it lets up look out the top half of the window while still insulating the bottom half.

Gary

Check out Home they are finally releasing there product this year. It is a layer you can add to glass that will tint the window based on the temp differance inside and outside. It will not help with keeping it warm in the winter but will help in the summer.

It is the trapped air that provides the insulation, and I've heard that the biggest space that works is about 5/8-3/4". Less than this provides less insulation, and more than this doesn't provide more insulation because the air starts to circulate because of the thermal flow.

So you can't just put double or triple layers of glass into the muntins that are designed for single panes. If you can fit 2 layers in, then great, but the air space is probably less than optimal.

Hi,
The graph I saw showed a peak insulation value at about 3/4 inch gap, but the drop off for narrower and larger gaps was quite gradual all the way out 3 inches. I'll see if I can find it again.

I guess I don't see why you can't put multiple transparent layers in spaced at a half inch to a couple inches not get an R value increment for each layer -- its the same thing that commercial triple pane windows do?


Edit: The Passive Solar Energy Book, Mazria pg 365 gives R1.01 for both 3/4 inch and 4 inch air gaps.

http://www.coloradoenergy.org/procor...f/r-values.htm shows
" 1/2" to 4" approximately 1.00 "

Could not find the graphs I saw before.

Gary

Thats an excellant list to have Gary. Thanks
Geo