The "R-Value" (resistance to conductivity) of an original wood window, plus a good aluminum storm is the same as a double insulated replacement window.
(The "R-Value" (resistance to conductivity) of an original wood window, plus a good aluminum storm; is; the same as a double insulated replacement window)
The "R-Value" (resistance to conductivity) of an original wood window, plus a good aluminum storm
is
the same as a double insulated replacement window