Q I’d like to replace the drafty single-pane
windows in my house. Is upgrading to
triple-pane windows a good idea in areas like
mine where it’s often below zero in the winter?
Debbie Parks, Portland, ME
A In cold regions, such as New England, triple-glazed
windows can save 2 to 3 percent of your
heating bill, compared with double-glazed windows.
From a cost standpoint, it’ll take a few decades to recoup
the 10 to 15 percent upcharge to go from low-e double-glazed
windows to triple-glazed. For example, if you pay
$1,000 per year in energy bills, have 20 windows in your
house, and 22 percent of your energy is lost through
your windows (which is average), then each window is
losing $11 worth of energy per year. A triple-glazed window
will reduce that loss by about $1, so it’ll take 35 years
to cover a $35 upcharge for triple-glazing. Of course, if
your energy bills and energy loss are greater, you’ll recoup
the cost sooner.
However, the investment may be worth the cost in
terms of comfort. Triple glazing will reduce condensation,
which will allow you to maintain a higher indoor
relative humidity in cold weather. These windows also
reduce cold drafts. If you don’t want to pay for triple-pane
windows throughout the house, get them for the
north- and east-facing rooms, where you’ll
get the biggest payoff.
Most of the major window manufacturers
in the United States don’t
offer triple glazing. But here are
two that do: Marvin (888-537-
7828; www.marvin.com) and
Weather Shield (800-222-2995;
www.weathershield.com). Many
Canadian window manufacturers
offer triple glazing.
Marvin’s triple-glazed window
consists of three panes of
glass, two of which have a
low-e coating. The space
between the panes
is filled with
krypton gas.
