Learn the Lingo

U Value
: a measurement of how
well a window keeps warm air in
and cold air out or the other way
around. The lower the number the
better. Current energy star (2010)
is .30 or lower.

Solar Heat Gain Coefficient: a
measurement that indicates how
well a window blocks the suns
heat. Once again, the lower the
number the better. Current energy
star for SHGC is also .30 or lower.

Insulated Glass: Also called
thermal pane, a double piece of
glass with a spacer that creates a
dead air space for increased
energy efficiency.

Low E Glass: Type of window
glass with a micro metallic coating
that reflects ultra violet rays and
reduces the amount of heat let in
by the sun.