window performance 101

energy_rater_laOctober 26, 2012

after reading through a few posts, I wondered..

does any one look for verification of how the

windows they are replacing/purchasing for new

construction are rated? how they perform in

the area they are being installed?

lots of brand questions, but no much about


e National Fenestration Rating Council (NFRC)

is an independent org. that tests and rates windows.

window companies pay to have their windows nfrc

rated to provide unbiased info to homeowners.

here is the link.

anyway..the important numbers on nfrc's label

are solar heat gain coefficient..shgc

and ufactors.

both these numbers should be below .32 for

a well performing window.

here in the south we want windows that keep

heat out..up north windows that keep heat in.

the location of the low e coating determines

how the window performs. inert gasses like argon

keep air at rest between the glass sections.

type of frame effects window performance.

a metal frame conducts heat..lowering performance

of lowe and/or arton windows.

good glass..bad frame.

non heat conducting frames..wood, vinyl, fiberglass,

pvc & wood clad with metal..allow window to perform

by not conducting heat/cold via the window frame.

good glass..good frame.

nfrc also has a new designation on their label

condensation rating. this is directly related

to window frame type. metal windows will have more

condensation than other types.

hope this helps to aid everyone in their window


if you are shopping windows that dont have nfrc

verification..keep shopping. let this label

guide your choices. its a shame to spend lots

of money on windows that don't help to keep

house warm/cool. big investment with long payback.

there used to be a window guy here at gardenweb..

don't know if he is still around. I actually

came here looking for him.

if you read a post by Oberon..its good info.

urge him to post here. he is missed on building


best of luck everyone.

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Hey ERLA!!

How the heck are you?

I haven't seen you around for a very long time.

So what's up with you?

    Bookmark   October 26, 2012 at 8:20PM
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I thought you were gone Oberon!!

glad to see you around again.

I've had a chance to do some diy at
my own house...for a change. nice
to finally get it done.

so your daughter's house is finshed &
she & family are in??

you visit this forum much?

could you do that low e location on IGU
explanation again that you do so well?
I'd like to send some folks from another
forum to read your posts.

take care & tia.

    Bookmark   October 27, 2012 at 12:04PM
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All is good here.

Send me an email, please and we can chat.

    Bookmark   October 28, 2012 at 11:14AM
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