Hi, ya'll. Been reading the forum for a while, but haven't posted 'til now.
Bummer, Lynn, about the Low E windows. We have a passive solar house that works incredibly well, and it was just before the Low E windows were required. But all is not lost with double panes. We do have double-paned windows, floor, wall, and ceiling insulation, and it's really the Very Small Eaves coming off the roof that allows the sun to hit the big bank of our south-facing and east-facing 5-foot-tall windows (northern hemisphere). As soon as the sun is on the windows in the AM I can feel the heat coming in. The interior quickly gets up above 70 F by late morning on sunny days, and stays that way well into the night.
I use blackout pull-down window shades next to the glass (very inexpensive) plus thermal, blackout curtains that help in the summer to block heat, as well as keeping in the heat in winter. We have mild winters, but the house is tied into the 50 F ground, and it rarely goes below 50 F inside. If it goes just below freezing outside the inside will go down to 45 F with no heat on. I am always surprised when I walk out in the mornings and feel how much more chilly it is outside. Plus it keeps the interior from feeling clammy and moist along with the cold, we have no mold problems at all.
One problem with the single-pane windows is that moisture condenses on the inside and can cause problems that way, including causing black mold to form on non-sunny sides of the house (or windows under big trees). We had that happen in a past house of ours, in a very mild climate. So double-panes do have their advantages, and also help in the winter with some heat loss.
