window performance 101
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
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.