GBG - what's the performance impact?

For all those Replacement Window questions
Post Reply
Message
Author
Beano
Posts: 26
Joined: Sat Mar 19, 2016 11:05 am

GBG - what's the performance impact?

#1 Post by Beano » Thu Mar 31, 2016 5:10 pm

Just curious - how much impact to performance does GRG (grids between glass) make in a window compared to no grids? I suspect it's negligible but would like to confirm. I'm asking as window ratings are typically based on units without grids as that is the optimal performance setup. But, since my home currently has grids, I'll probably run them top & bottom in the replacements to keep the architectural style intact (leaning toward Okna).

User avatar
Delaware Mike
Posts: 864
Joined: Mon Jan 30, 2006 1:32 pm
Location: Delaware, New Jersey, Philadephia Area

Re: GBG - what's the performance impact?

#2 Post by Delaware Mike » Thu Mar 31, 2016 5:38 pm

I've never seen it change the overall u-factor in reference to the NFRC sticker on a window verses a non-grid window. OKNA seems to do a really nice job with their grids in terms of quality control as that's an area in which all manufacturers encounter some small percentage of misalignment during the manufacturing process of the glass.

User avatar
Window4U (IL)
Posts: 1374
Joined: Fri Mar 11, 2005 3:58 pm
Location: Sales and Installation in Chicagoland and Central Illinois

Re: GBG - what's the performance impact?

#3 Post by Window4U (IL) » Thu Mar 31, 2016 6:55 pm

On pretty much all the brands I've carried it's been a .01 difference. An example would be a .26 with GBG grids, a .25 without GBG grids.

Beano
Posts: 26
Joined: Sat Mar 19, 2016 11:05 am

Re: GBG - what's the performance impact?

#4 Post by Beano » Thu Mar 31, 2016 7:28 pm

Thanks much. That's what I was hoping to hear.

masterext
Posts: 707
Joined: Wed Feb 01, 2012 9:14 pm
Location: New Jersey Window Pro- Northern NJ and Central NJ

Re: GBG - what's the performance impact?

#5 Post by masterext » Thu Mar 31, 2016 9:47 pm

I dont believe okna is affected by adding grids to their double pane units. At least with the 500 and 800 series .

User avatar
HomeSealed
Posts: 2424
Joined: Tue Feb 16, 2010 6:14 pm
Location: Milwaukee, Madison areas
Contact:

Re: GBG - what's the performance impact?

#6 Post by HomeSealed » Thu Mar 31, 2016 11:04 pm

I've never seen the u factor of an okna window affected by grids. Only vt and shgc for obvious reasons, and only a negligible amount

User avatar
Windows on Washington
Posts: 4438
Joined: Wed Apr 04, 2007 11:21 pm
Location: DC Metropolitan Area-Maryland/Virginia/DC
Contact:

Re: GBG - what's the performance impact?

#7 Post by Windows on Washington » Fri Apr 01, 2016 5:54 am

I have seen a 0.01 delta one time. Can't remember which window, but that would be the largest offset and it is basically negligible.

masterext
Posts: 707
Joined: Wed Feb 01, 2012 9:14 pm
Location: New Jersey Window Pro- Northern NJ and Central NJ

Re: GBG - what's the performance impact?

#8 Post by masterext » Fri Apr 01, 2016 2:14 pm

Eric
I seem to recall the 500 series in triple pane going from a .19 to a .20 with grids.

User avatar
HomeSealed
Posts: 2424
Joined: Tue Feb 16, 2010 6:14 pm
Location: Milwaukee, Madison areas
Contact:

Re: GBG - what's the performance impact?

#9 Post by HomeSealed » Fri Apr 01, 2016 10:06 pm

masterext wrote:Eric
I seem to recall the 500 series in triple pane going from a .19 to a .20 with grids.
Good catch Paul. The double pane is is the same with and without, but the triple pane does change by a point according to the nfrc. Probably not an incredibly common combo, but it's there none the less.

Post Reply