I'm in the process of getting estimates on 14 replacement windows (36inx52in) here in the Northeast. I used Home Depot as a high $$ benchmark. they are offering their 6500 series windows with double pane glass installed for $8200. this includes wrapping of extererior etc..

I recieved quotes from another installer with decent track record.

They however offer this Generations window (made by Simonton or Reynolds?)

they have 2 offerings. the double pane and triple pane product.

- $7900 for Generations with Energy Wise package featuring
Double-glazed 1" insulated glass unit
Argon gas filled between the double strength glass panes
Low-E soft coat
Terrained Super Spacer®
low e 366 glass

or

- $8900 for Generation Energy Wise Plus glass package
Triple-paned 1" insulated glass unit
Krypton gas filled between the double strength glass panes
Two surfaces of Low-E soft coat
Dual-sealed silicone foam Super Spacer®

The installation from this company does not include wrapping the exterior in vinyl but they will insulate around the frame properly so no air is leaking through the trims. Will ahve this in writing on SoW.

My questions are:

How is this Generations product line compared to the Simonton windows?
Is it a good window?

The R value on the tripe pane is much much higher with a U rating of .22 vs the .29 on the double pane. Is this worth the extra $75 per window?

I live in the NE and spend around $3k a year on heating costs in the winter alone. Is .22 vs .29 going to be a worthwile difference in cost savings for the $75 per window?

I believe that U-rating in the US is in BTU/hr/sq.ft.

If that is the case, look up your "degree-days" and multiply out:

(0.29 - 0.22) BTU/hr/sq.ft./degF
* 14 windows
* 12 sq.ft/window
* (?) degF-days
* 24 hr/day
* 1/100,000 therms/BTU
* (?) dollars/therm

if I understand the units properly.

With Nebraska having around 6000 degF-days/year that works out to something on the order of 17 therms a year. I don't know what your utilities run, but in San Francisco gas is $1.25/therm. Even with heating inefficiencies included, it looks like a couple dollars a window, at most, per year.

Unless the difference is a tax incentive or not, it doesn't seem as though the $75 difference per window is justified by heat loss through the pane alone.