We just had 18 windows replaced (old single pane) with new double hung windows, low-E, argon filled, manufactured by Harvey Industries. The windows have welded frame and sash, PPG Intercept Spacer, 7/8.G thickness, 20 warranty on the glass, lifetime on the parts. U-Factor on them is .33, R-Value 3.03, and Air infiltration rating of .14 cfm/ft2.
Galaxy Glass did the installation and we are very happy with the work. Work looks great, caulking was well done, capping of the windows, etc. They did a wonderful job of cleaning up after themselves and even capped a window we installed ourselves last year free of charge. We had removed blinds and curtains the day before they came and they re-hung all the blinds for us (we never asked them to) and most of the curtains.
So far we are pleased and can already tell a difference with them with the temperatures dipping into the frost zones at night already.
800-399-4623