On 5/9/2012 10:06 AM, Jim Yanik wrote:
....

vinyl does not conduct heat as well as aluminum,so vinyl window frames will
have a higher R rating.

Not necessarily; there's a thermal break on an Al clad window; it'll
depend on the particular windows compared as to who wins.


maybe lighter,too,so easier to raise and lower.

They'll have the load matched to the weight just as any other window...

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