A friend of mine who is a contractor turned me on to two jeld wen windows that were installed then removed because they were built with the low e glass installed backwards. They are both huge very nice picture windows one over 10 by 5 feet, expensive windows. Does anyone know what would happen if i installed them anyway. Any help greatly appreciated. i would really like to use these windows. Im in southern NC.

A couple of quick thoughts

Conventionally, window surfaces are number from inside to outside. So the #1 surface faces the exterior. And the #4 surface faces the interior (double glazed unit)

Can you determine the location of the low-e coating?

A low-e coating on #1 or #4 doesn't do much good from an insulating point of view. In fact if it's a sputtered (soft coat) low-e it will corrode over time - obscuring the view (not good)

If the low-e coating is on #2 or #3, then you've got something more useful. In either case the U-value remains the same. In your area i'd prefer to have the coating on #2, because it will block more heat from the sun (higher SHGC) reducing Air Conditioner loads.

Sorry but i am alittle confused about the numbering. From the outside of the window when i hold a lighter up to the glass i see two double flames. of the four flames the third one from the outside is a little more of an orange color. I guess the coating is on the outside of the interior piece of glass. Another window, properly constructed but rejected for asthetic reasons has the coating on the inside of the exterior glass. My question is will this cause any other problems besides a slight loss in eff. Thanks ahead of time for any help.

 

The two windows with different low-e locations will insulate the same, if they are otherwise similar

There will be a slight difference in SHGC - Solar Heat Gain Coefficient.  In other words one will block more free heat from the sun. 

If you had the choice you might want to put the one with the low-e on the #2 surface (inside of the exterior glass) on the west because it will reject a bit more of the sun's heat. And the one with the low-e on the #3 surface (outside of the interior glass) on the south because it will accept more of the sun's heat......

There may be a very slight difference in the appearance of the two windows if they were placed side by side.

All in all i wouldn't worry about too much, sounds like you got a good deal to me.

Stephen, Thank you very much for the help. I really appreciate your help. I am building this house with as much used material as possible but these Jeld wenn picture windows possibly the best score yet. Free and brand new. Thanks again. Michael