Windows — Pretty Good or better in Western Colorado
I am looking for windows for a Pretty Good house I am preparing to build in Carbondale, CO at an elevation of about 6,200 feet. Climate zone is 6B. We get lots of sun here and large diurnal temperature swings, year round. I don’t know of any homes in town with air conditioning. I’m looking at Pretty Good insulation levels, R-5-10-20-40-60 and about 6 to 8% south facing glass with fairly low thermal mass — partial tile floors and 5/8 drywall. Windows on the north and west will be limited. I’ve heard that 4% overall operable glass is a reasonable target. My rooftop will have excellent exposure for PV.
Our access to window manufacturers is limited compared to more urban areas. One of the issues I’m running into at this altitude with manufacturers like Loewen, Marvin/Integrity, and Sierra Pacific is that they will either not offer Argon fill, or they will fill them with Argon but won’t guarantee the level of Argon fill. Apparently this is because the windows will “breathe’ through a capillary tube to compensate for altitude changes in transit. So an Argon fill on those terms would perform somewhere between air and argon fill levels. If the glazing units are sealed, bulging results that can lead to cracking, seal failures, or visual distortion.
I’d like U of 0.20 or better, VT of 0.5 and up, SHGC for south wall of 0.5 plus.
I’m not sure I’m prepared to spring for PassivHaus grade, but I’m open to suggestions. I haven’t been able to determine if Intus has a dealer that covers our area. There is a local Kneer-Sud representative. Zola has an office in Steamboat Springs, about 2.5 hours away.
Any personal experience with the merits and drawbacks of tilt & turn windows? It seems they could impose some awkward constraints on interior space adjacent to windows.
I’ve also been wondering about the wisdom of buying a high-tech, expensive windows from Europe and how potential warranty issues might be addressed — if the companies are still around!
I’ve tried to read all the excellent posts on glazing here. In one post, Martin wisely advised buying windows manufactured on your side of the Continental Divide to minimize issues associated with hauling windows over high mountain passes. My challenge is a climate/location/elevation specific issue.
GBA is a fantastic resource. Thanks to all of you who make it so!
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