Passive Solar Application in Ohio

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Passive Solar Application in Ohio

#1 Post by Ohio » Sun Sep 02, 2012 10:59 am


Thanks for all the info. in the past concerning our project (special thanks to Windows on Washington)

We are in the process of getting Rehau 4500 Tilt Turn windows with Cardinal Glass.

Glass will be the 1 3/8 triple IG UNIR. LE 180 /CLEAR/LE 180 with argon.


1.) Glass Thickness: Option is to go with 1/8 glass or 3.9 mm glass. 3.9 mm glass puts the argon space between the panes right in the middle of 1/2 inch and 7/16 inches range - read that this is the optimum spacing and that the slightly thicker glass will reduce sound. Currently no up charge to go with 3.9 mm glass & for the units that require tempering, I've been told that the thicker glass is less likely to distort. Any incorrect info. here or drawbacks I should be aware of?

2.) Spacer: Current spacer for the IGU is an Ultraspacer. Is this the best spacer for this system?

3.) Requirements for Tempered Glass. It is my understanding that glass panes over 9 sq. ft. that are less than 18 inches from the floor, greater than 3 ft in height and near a walking area must be temper by law. Is this correct and are there any disadvantages to tempered glass?

Thanks again to all.

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Windows on Washington
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Re: Passive Solar Application in Ohio

#2 Post by Windows on Washington » Mon Sep 03, 2012 11:24 am

1. That is fine for argon spacing. As a general rule, most folks state that 1/2" is optimum for argon but 7/16 - 1/2" is just fine.

Not sure on the size of the windows but the thicker glass (20% in this case) will be better for sound attenuation and while 1/8th glass doesn't normally distort, the 3.9mm will be that much less likely to do so.

Only drawback would be weight and stress on the frame. Most tilt n turns are overbuilt so they should be more than fine.

2. If the Ultra is the stainless version of the intercept, that is a well proven design. I prefer non-metallics when you can get them, however, all the major spacer manufacturers are well proven.

3. That is pretty much the code on tempered glass in those non-stairway, bath, door, and pool applications.

Only disadvantage to tempered glass is the added expense.

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Re: Passive Solar Application in Ohio

#3 Post by TheWindowNerd » Mon Sep 03, 2012 6:18 pm

It would be interesting to see the STC for each glazing option.
Also I am curious about the normal perception for each STC point by the average person.
Depending on the width and height of the IGU I might stick with the "1/8" to max out the air space, particularly if it does not change my seal failure warranty.

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