Is high solar gain glazing worth the extra money in mid-Michigan?
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We are currently building a home in midwest MI. It has a mono-slope/shed style roof with the tall wall (14′, total of 66′ long) facing approximately 15 degrees east of true south. We will have concrete floors throughout the main level (and basement), infloor heat. Limited, small windows on the west/east/north side. We have tree shelter on the west and north sides of the home.
We need to decide on windows soon… Wwe found high solar gain glass (the same as the Cardinal Low-E 180) is available on Anderson 400 windows. Is it worth it for us to pay for to upgrade to the high solar gain glass in this climate, with this orientation? I haven’t seen many people go for it, although I know it is often recommended.
2’x6′ construction…R60 ceiling, R24 walls.
Thank you in advance for your expertise.
Cara
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Replies
Q. "Is it worth it for us to pay for to upgrade to the high solar gain glass in this climate, with this orientation?"
A. Generally, yes -- high-solar gain glass is best for northern locations (cold climates). However, you didn't really give us enough information. To do the math, you need to tell us the incremental cost of the high-solar-gain glass, your heating fuel cost, and the anticipated annual energy savings.
Even with all that information, only you can decide what kind of payback period makes sense for you.
Just some questions to maybe chew on from a diy guy. How are you getting R24 in a 2x6 wall? Is that over the whole wall, or just the insulation? Is a double-stud wall out of the picture? What is the value to you of extra comfort sitting in front of better windows? Why worry about what most people "go for"? IMO, people would rather spend money on restaurants and fancy faucets than better windows, so most folks are not the best of guides on this.
Thanks for the thoughts, and sorry about the lack of other information, I was at work when I posted it.
The upgrade for the glass is $1400 for our south facing windows. We have clerestory style windows on our high south wall 3'x1.6', operating for summer ventilation as well. We have about 82 square feet of other south facing glass on that side that would be high solar gain glass as well.
Our construction is pretty well set, as far as the 2x6 wall and insulation. We are between 2 mechanical systems but will have an infloor heat that we are planning on running at a lower temp (60ish) and an indoor wood stove to bump up the temp when we are home. We don't run our house hot now (65ish) so we are pretty sure that's realistic. The heating fuel cost as calculated doesn't take into consideration our living style. I don't know what the anticipated annual energy savings would be or, in my mind, it would be an easy answer. :) The people we have talked with regarding this glass are quite unknowledgeable in this area. They have found it, and agree that it is available, but are still unsure as to why we want it.
I just wanted to see if others with a similar climate have had experiences with the high solar gain glass, as it is often recommended when talking about green building in northern climates. We are trying to insulate well and use a passive solar design, but are aware that it will not be close to PassiveHaus standards (we are an "open window" family living on a farm and are unable to build to those specifications at this time...). I don't know if that information helps; I'm not really looking for a debate on building styles, this is just what is working for us at this time.
Thanks!
Cara