I'm searching for affordable "super windows"  and have an observation to share.  Essentially all US and Canadian window makers  DO NOT have window designs that properly accommodate tipple pane glazing, even if they might offer it.  Most tipple glazed offerings use 1" over all thickness IGUs,  This limitation is very costly in thermal performance causing the center of glass thermal conductivity to rise by about 1/3 over a 1 3/8" IGU.  OTH the imported European windows often have glass of 2"+.   Here is a link to the Cardinal glass table of performance:  http://www.cardinalcorp.com/technology/reference/loe-performance-stats/
So I'm now searching for window makers that have standard products that'll accommodate the 1 3/8" IGU,
If you know of any please share their names.
So far I've identified only two:  Sunrise (their frames & sash are PVC with foam insulation & they offer a lifetime transferable warranty)
and HH ( Frames & sash are wood with optional aluminum exterior they use european hardware & feature tilt & turn)
 

Posted By Liebler on 03 Jan 2013 08:18 PM
I'm searching for affordable "super windows"  and have an observation to share.  Essentially all US and Canadian window makers  DO NOT have window designs that properly accommodate tipple pane glazing, even if they might offer it.  Most tipple glazed offerings use 1" over all thickness IGUs,  This limitation is very costly in thermal performance causing the center of glass thermal conductivity to rise by about 1/3 over a 1 3/8" IGU.  OTH the imported European windows often have glass of 2"+.   Here is a link to the Cardinal glass table of performance:  http://www.cardinalcorp.com/technology/reference/loe-performance-stats/
So I'm now searching for window makers that have standard products that'll accommodate the 1 3/8" IGU,
If you know of any please share their names.
So far I've identified only two:  Sunrise (their frames & sash are PVC with foam insulation & they offer a lifetime transferable warranty)
and HH ( Frames & sash are wood with optional aluminum exterior they use european hardware & feature tilt & turn)
 

You hit the nail on the head.

That is the same observation I came across. US window manufacturers are basically trying to squeeze triple pane glazing into a frame that is designed for only double pane windows. In doing so, the window size must be greatly reduced and a slew of other problems are beginning to emerge. They basically don't want to retool their frames (aka $$$$) to carry the size and weight of triple pane glazing so they are cutting corners by trying to put a triple glazing into the double glazing window frames.

Compare a European Triple Pane window frame to a US triple pane window frame, the difference is quite astonishing. In addition, Cardinal glass is the US standard and they use the exact same spacing within their glazing units. Compare that to Guardian glass, they use vastly wider glazing spacing and you can't compare the glazing between the 2 glazing manufacturers, it's not apples to apples. The wider glazing spacing changes U-Values.

When I attempted to get triple pane glazing by the US manufacturers that sell triple pane, the engineers could not accommodate the larger window sizing. While the European triple pane manufacturers not only could accommodate the large sizing but they could even accomodate much larger window sizing.

Take a look at Intus Windows (European Triple Pane Windows).

Lbear,
Sunrise designed a sash system to accommodate a double pane + blind and accidentally, I'm sure, made it able to accommodate a true triple pane IGU. HH is basically making European designs in the US and can easily accommodate a true triple pane IGU. I'm hoping that there are others. It doesn't look like the Pella internal blind sash will work with a triple pane IGU. There must be others!

Posted By Liebler on 03 Jan 2013 09:41 PM
Lbear,
Sunrise designed a sash system to accommodate a double pane + blind and accidentally, I'm sure, made it able to accommodate a true triple pane IGU. HH is basically making European designs in the US and can easily accommodate a true triple pane IGU. I'm hoping that there are others. It doesn't look like the Pella internal blind sash will work with a triple pane IGU. There must be others!

Not until they engineer and retool their frames, it will not happen. Right now US manufacturers don't see the profits in manufacturing triple pane windows so they will continue with their current business model. It's like the rest of the entire home energy build science, the US is 15 years behind the curve, if not more. The 2012 IRC is attempting to address this problem but most counties will not adopt the 2012 IRC for years and if they do, they will amend most, if not all of the energy codes.

They were using triple pane glazing in Europe back in the 1980s.

I looked at a new build the other day and they were installing U-Value 0.35 windows that were so flimsy I could rack the entire assemble with one hand using very little force.

I went with Kolbe and Kolbe Ultra EP windows for my house. They are being delivered next week. They use a 1 3/8" sash unit. They are not a European super window by any means, but they are one of the best US windows I could find in triple pane and wood interiors for a decent price. They were approximately the same cost of fiberglass Inline windows with nearly the same performance numbers. The upgrade to triple pane was only around $60 per window. The glass options are nearly endless. My rep was great to work with to select glass tuned to my elevations.

Izerac,
      Thank you for the vote of confidence to Kolbe & their EP windows.  Did you get the aluminum exterior option?
 I found them last night along with Wasco as two more companies that offer 1 3/8" IGU glazing.

I went with the Ultra series, which is heavy extruded aluminum exterior with minimal contact with the wood frame structure. It has wood interiors.

We started installing them. I have pics and a review started here: http://ths.gardenweb.com/forums/load/windows/msg012241589068.html?4

Marvin does it, Loewen does it, Kolbe and Kolbe, Eagle....You just need to make sure and ask the right question(s.)

The proof is typically in the pudding.  Who cares if someone claims their product is octo pane, if the U values aren't up to snuff then you know something is amiss.

In this case I would offer you to check Intus Windows. They are manufacturers and basically you will be getting good quality European windows. Their overall thickness is 2". I copy the link where you can find all characteristics you are looking for. This is really helpful:
http://www.intuswindows.com/products/u-pvc/windows/eforte/resources.html
We installed many Intus energy efficient windows and doors and every time it fits requirements perfectly.

In this case I would offer you to check Intus Windows.

Are you an Intus dealer or do you have some other financial connection with them?