Price out the R-11 window and see what the numbers are like. That is the window with triple pane glass and two layers of Heat Mirror. That is the window that has the <0.10 U-Factors.

The 1125 Serious Windows is also a dual pane window with a very wide IG. It has three of the suspended films.

That is the window that I was referring to. I was mistaken in stating that it was triple pane glass when it is actually a dual pane IGU with the 3 suspended layers as you mention.

Extremely expensive window.

Posted By PVonDy85 on 11/01/2009 11:15 AM
"I  believe U values were created to confuse customers and sell more windows".

I would suggest that is unlikely since U-values have been in use in energy performance calculations since the 1940's while R-value was introduced in the 1970's primarily by the pink fiberglass insulation folks.



Posted By PVonDy85 on 11/01/2009 11:15 AM
"But when you convert those results to U values I think it tricks consumers into believing there is a bigger difference because the numbers look much more different. I have found that most window sales people don't even know the difference between R value and U value".

While I would agree with you that salesfolks (and a lot of other folks) often don't understand the difference between R value and U value (or U factor as applied to windows), to suggest that windows need to be "converted" to U value from R value is incorrect.

In fact, window performance is calculated using U value so that if a window company chooses to advertise overall R value versus U value (as opposed to center-of-glass measurement), then it is necessary to convert to R value from U value since overall window performance can't be computed from R value numbers.

The Serious Windows got my attention. Anyone here have these windows, or know someone that has them? Curious to see what the experience is. The suspended film, or heat mirror, layer(s) between the glass, is this the same heat mirror idea that Hurd Windows (and other window companies) offered several years ago? My parents went with the Hurd Heat Mirror casement windows when they built 7-8 years ago. Within a few years, you could see a purple color or haze in the glass in most of the windows. Hurd covered the cost of replacing all of the glass, but discontinued the heat mirror option. I believe my parents got the low-e glass when it was replaced.

When I got my quote for Serious Windows, they were for new construction. The sales rep and I had a long conversation about several jobs they had been installing them on, all of which were new construction. I did not get into the specifics of flange details with him, but he new for sure that there were for new construction and I can not imagine him forgetting to mention that they only sold replacement windows.

Even if they didn't have the right flange, I have used "replacement" windows for new construction before. In fact, the double stud house I recently posted elsewhere on the forums actually used triple pane replacement style vinyl windows. We built the rough opening a little small, then used a hand plane on the edges of the frame to get a perfect fit. (Don't worry, the windows were designed for this.)

Care to share any details of your quote?  I'm interested in these windows, but not sure how much more they are than a "standard" window.  Did you get an idea of how much more the Serious windows were?  I know it's probably tough to nail down what's "standard" but any ballparks?

I have been pricing windows lately. Here's a comparison between Marvin and Serious for a 56"w x 60"h double casement unit. Both quoted with oil-rubbed bronze hardware and screen.

Marvin: Alum. clad wood, Low E II w/ Argon U-value .32 , wood screen, 6 9/16" jamb, quoted at $1013.25

Serious: fiberglass 725 Series, SeriousGlass 9 U-value .17, applied screen, quoted at $1449.17.

The infiltration numbers for the Serious casements are superb as well.