Magic windows?

[Bad Wolf]

I went to the Conn. Home show last week just to see what they had. After tormenting the tree/wood guy about his seasoned-split last week wood, I stopped by the window people.
I’m looking at windows for the next house (retirement) which I’ll hopefully be building in three years or so. Now these replacement window people are boasting triple pane, argon/krypton filled, low E windows with a rating of around R-10. (they also tried to sell me some snake oil)
When I research new windows online the best I find is around R-5 for the same kind of construction.
Who are the reputable window manufactures out there, and what are the “real†R values?
I’d like to do a return on investment on 2 vs. 3 pane construction.
I intend on using all of the new technologies: spray foam, foam cladding on the outside, sealing every last seam and joint, foundation insulation etc. so good windows are a must.

On a side note I learned that when they replace a window they are just ripping out the moving parts of the old window and slapping their replacement window inside the old frame instead of removing the old window to the rough framed opening. I asked, why would I want to spend that kind of money and still have the air leakage around the old window? They didn’t have an answer.

 

[midwestcoast]

I think your "Spidey Sense" was working properly. It would take a very new revolutionary technology to get triple pane low-E windows at R-10 and that would not have happened without enough publicity that anyone working or interested in green building would know about it. Using the existing wood or vinyl frame further discounts the claims.
It's really a shame to hear that these guys are ripping-off people who are looking to save energy.
The most insulative windows I've heard of are from these folks: http://www.seriouswindows.com/ Using double-panes with multiple layers of plastic film suspended between the panes and foam-insulated fiberglass frames.

 

[basswidow]

So you were not really getting a full window - right? If they are just slapping them into the exsisting frame.

I have a love/hate with windows. I have a 5 year old home with Anderson windows. I have two types. Standard raise and lower and some that are full crank out types in the kitchen and bath. All are double pane and nicely constructed. The crank out ones - are great (they are seal tight). The standard slide type windows with the lock in the center and tilt out tabs, just seem drafty. I think the lock causes alittle forced gap in them and the tabs don't snug them enough in the slide. We get alot of wind and these windows disappoint - wind blows thru around the window frames. I really don't think triple pane would make any difference at all. I think the air loss is in the installation around the framing and gaps in seams. I really think storm windows would be the answer for me. Right now I have to use shrink plastic.

Seems like someone could make a better window.

 

[midwestcoast]

Also, I'd advise using "Whole-unit" or "Full-Frame" R-values (or U-values) versus the often quoted "Center of Glass" values which virtually ignore the effects of edge spacers and frames. Be suspect of any specs that don't distinguish btwn center of glass & full-frame values. Although not easy to source, it's worthwhile trying to get higher Solar Heat Gain windows on the south side if you have significant unshaded south glass. Low SHG glass is great for keeping East & west sun out in summer, but no need ont he south side where sun only hits in winter.

 

[begreen]

There are some very expensive R 9 windows out there. My brother in law put them in their solarium/greenhouse attached to the house. When I asked how expensive, he said, you don't want to know. I was there in late December and I will have to say that they really do work. SeriousWindows says they have an R=11 system.
http://www.seriouswindows.com/html/fiberglass.html