Alpen Energy Group, LLC of Boulder, Colorado, has been leading the way in high performance window manufacturing for the past 20 years, are again raising the bar for all their competitors.  In this month's Environmental Building News, Alpen announced they have been able to make an R-20 window - that's the same as 5" of Icynene!

These windows, designed for extreme cold weather on northern building facades, are made of two layers of low-iron glass, 3 layers of heat mirror films, and filled with Xenon gas.  Not a simple or cheap window by any means, but an incredible achievement for the high-performance home world. 

When homes are correctly designed for passive gain, with limited windows on the north side, the relatively small additional investment in these high-tech windows can account for significant energy savings.

Wow!!

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