m Ransley wrote:
You have to compare certified ratings, for U value, cdf, vlt, shg etc
etc are they LowEargon, hardware quality and more, check out both sites.
Comparing takes time. Construction quality is another issue. If you
specified a certain window and these are less in performance you have an
issue.


To be exact you would, but any decent vinyl frame
window will greatly reduce heat loss compared to
an aluminum frame window. One caveat, there are
some aluminum frame windows that have a heat
transfer break (hard plastic) molded in the
aluminum frame which are considerably better than
regular all aluminum frames. None the less, even
comparing those, the vinyl frame window should be
an obvious improvement.