Windows and low-e coating
I have always understood that low-e windows worked in cold climates when you had the low-e on the exterior side of the pane closest to the interior (surface 3) and vv for hot climates (surface 2). This is stated pretty clearly in the book Residential Energy, for example, which most energy auditors use to train from, and I just checked with the DOE website and they say the same thing.
Today, however, I had 3 different conversations at a green building conference. One was with a rep for a major window manufacturer who agreed with the surface 3 idea. One was with a rep for another major window manufacturer who said they used to do that but now always put it on surface 2 because when they had it on surface 3 the pane would heat up too much thus heating the airspace too much and the seals would break and they had too many warranty problems. The third conversation was with a very well-known green building expert who said they are put on surface 2 as they are really heat mirrors and reflect heat back onto the room.
The name “low-e” would make you think that originally it was intended for surface 3 in a heating climate.
Can anyone enlighten / confuse me further?