SHGC - does it only matter with direct sunshine on window?

fromhollywoodOctober 12, 2009

I'm in the process of making some double pane insulated glass units as storm windows. Oberon has really helped me understand these glass/window concepts but I'm still a bit confused about SHGC.

I trying to pick glass that will have a high SHGC number to get the benefit of passive solar heat (I'm in the Northwest where summer temps rarely get very hot but winter nights are routinely in the 20's F). Half of my windows though never get any direct sun hitting them during the year. Would it be better on those shaded windows to forget a high SHGC and get a low SHGC number instead?

Thanks very much for any ideas you could share.


Thank you for reporting this comment. Undo

If the windows are largely shaded, throw the SHGC component out of of the equation and stuff the best U-Factor window that you can in there. Look for a two surface low-e or triple pane. If you don't like the idea of less light, I would look for a window with Low-e on surface 3.

    Bookmark   October 14, 2009 at 5:58PM
Thank you for reporting this comment. Undo

Hi WindowsonWashington,

Thanks for the tips. I'm doing the double-pane storms since I want to save the historic windows.

I'm also replacing some cheap aluminum single-pane windows with some new ones. I find most of the big window companies don't give much in terms of technical details. Is there someplace where you can find out exactly what the specs are for the glass in a company's windows? I've been looking at Jeld-Wen vinyl windows and can see their performance specs but I'd like to know exactly what each piece of glass is and it's coating.


    Bookmark   October 16, 2009 at 2:45AM
Thank you for reporting this comment. Undo

Cardinal and PPG publish U-factors and SHGC for their glass on their websites.

Here is a link that might be useful: PPG Site

    Bookmark   October 16, 2009 at 7:01PM
Thank you for reporting this comment. Undo

Here's the Cardinal Glass link

Here is a link that might be useful: Cardinal Glass

    Bookmark   October 16, 2009 at 7:09PM
Thank you for reporting this comment. Undo

Skydawggy, Thanks for the links to Cardinal and PPG.

Do most of the big window companies like Jeld-Wen use glass from one of these two manufacturers? I seem to remember hearing that there are really only a few glass manufacturers in North America but I've never confirmed that.

How do you get out of the window manufacturers exactly what type of Cardinal or PPG or other manufacturer of glass is being used in a specific window? For instance, Jeld-Wen seems to have just a few glass choices when you look at their link called "Performance Ratings". I called their customer service but they didn't have an answer for me.

This is the only thing on their website that I can find that says anything technical about the glass and it's not too specific. They list "Clear", "Low-E 272", "Low-E 366" as the only choices but they don't say who makes the glass or what type of coating is used.

    Bookmark   October 18, 2009 at 3:32PM
Thank you for reporting this comment. Undo

LoE 272 and LoE 366 are Cardinal glass. PPG uses Solarban 60 and Solarban 70 as comparable glass. I would just simply ask the Jeld Wen dealer what glass they use. I'd tell you but I really don't have any dealings wih Jeld Wen.

    Bookmark   October 18, 2009 at 9:45PM
Sign Up to comment
More Discussions
Quick advice re: matching door and window grills & transom size
I have french doors sitting between two sets of side...
Curtain Finials
These finials were purchased a number of years ago...
Looking for recomendations re: replacing sliding patio doors in MN
As the title says, I'm researching replacement our...
Install expectations?
just had windows installed and before I complain to...
Opinions on Sunrise vinyl sliders?
I bit the bullet and went with Okna windows! Not biting...
© 2015 Houzz Inc. Houzz® The new way to design your home™