Hello all, Need some help! I live in the Chicago suburbs and currently looking to replace some old R.O.W windows that have spacer and rotten wood issuses. Was considering Tri Pane windows with a u factor of .24 or less but my sales guys are saying for this area its not worth the price. Is this true?? Currently looking at Marvin Ultimate, Marvin Integrity, Kolbe, Loewen.  I was thinking the lowest u factor would be best but they say not to spend money on it because you want the higher SHGC  then the u factor. Needing some advice! thanks

Go for it. why not maximize the insulation value of your windows? If you depend on these windows for solar gain, you can order them with a different glass which would have a higher SHGC. For the record, it's not only a "value" consideration - a triple pane window will have a higher interior glass temperature, so it will be more comfortable to sit near.

I priced Straussberger windows and doors in both double and triple pane, there was only a $2100 difference, so I went triple. Stuart

I have owned tri pane Anderson windows in my Ohio home and they are casement. I do love them but I am not certain (circa 1983 install) that I would do it again when I can get the same performance from double paned windows. Attached is an interesting study that I found that compares various changes to a house. I was surprised by the data on high performance SHGC windows compared to other changes.

http://www.energyvanguard.com/blog-building-science-HERS-BPI/bid/38931/Case-Closed-Get-Those-Air-Conditioning-Ducts-out-of-the-Attic

Scroll down to the graphs to see what changes do to the efficiency of cooling and heating a space.
I know one thing I am sure going to pay attention to a lot of things in this study.
Hope this helps some.
I am faced with buying all new windows for a new home but mine are impact glass. That said I am beginning to think that the SHGC isn't as important as I had thought it was...

I would take Marvin over Kolbe in a heartbeat. Alot of Kolbe stuff in my area and I've been around most of their lines, it's stuff that looks fine when you unwrap it, then you take a closer look and you realize its not that great or actually quite crappy. Some of their stuff is ok, and some of their products are complete garbage, especially for a company building in a cold climate.

And I have tried using their products every now and then thinking they will be better since they come off as a higher end company but they always fall short. Service is good, but that may be because the factory is close. I cant comment on Loewen, never put those in.

I would put Pella, Andersen or Jeld Wen in over Kolbe, but Kolbe over Weathershield, Semco or Lincoln. I don't think many of those brands offer triples though.