Shop Products
Houzz Logo Print
energy_rater_la

window performance 101

energy_rater_la
11 years ago

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

performance...

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.

http://www.nfrc.org/label.aspx

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

choices.

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

forum.

best of luck everyone.

Comments (3)