How important is filling the space between two panes of glass with argon or
krypton, compared to low-e coating(s)? Are two low-e coatings (on
different surfaces) twice as good as one? Does it matter which surface the
low-e coating goes on?
One guy wants to sell me replacement windows with two low-e coatings but
filled with air; another guy wants to sell me windows with a low-e coating
and argon-fill (both claimed to have an energy star rating).
Are all low-e coatings the same or equally effective, or do I have to ask
exactly what the multiple layers are?
Are triple-pane windows enough better than double-pane windows to consider?