So the thing I keep hearing about energy efficient windows, is that low-e coating is the way to go over double or single pane windows.

The pros for Low-e coating seems to be that you don't have to replace the IGU's just a couple of years down the road while getting almost the same insulation. What does everyone think about this? Educate me! haha.

Low-e coating just means that they put a microscopically thin layer of some deterring metallic substance onto a window glaze (i.e. the glass). This technique is typically used on double- or triple-glazed window units. You aren't likely to find any energy efficient single pane windows out there, it's just not possible with only one layer. It's also common to use multiple methods such as low-e AND a gas fill.

the insulation of a window with clear glass and LoE 272 or LoE 366 (Cardinal brand glass) is about as different as night and day. You can tell a huge difference between the heat build up on a double-pane window that is clear glass and one that has a loE coating if the window is in the direct sun. I wouldn't have a window in my house without LoE coating on it.

BRINDASBABY "I wouldn't have a window in my house with LoE coating on it."

What are you inferring? Please explain!

John

I love the Low e coating, I use it in every house I build, it reflects to the heat side ......... keeps heat in during winter and heat gain out during summer

Unlike Argon gas, I think the low-e coating will stay around for the life of the window.  I like Argon in windows but I can not find any standards for its use and life in windows.  Window manufacturers have told me that the gas will slowly escape.

i apoligize regarding my typo.  my post should and now does say "I wouldn't have a window in my house without Low-e glass"

Posted By Alton on 02 Aug 2010 07:54 AM
Unlike Argon gas, I think the low-e coating will stay around for the life of the window.  I like Argon in windows but I can not find any standards for its use and life in windows.  Window manufacturers have told me that the gas will slowly escape.

Alton,

Most manufacturers are utilizing a dual sealed IGU.  The primary seal is to provide the stability for the separation of the glass and grids as well as a barrier against other atmospheric gases.

The secondary seal, usually PIB-Polyisobutylene (Butyl) rubber, provides the seal against gas loss.  Most manufactures are projecting gas loss rates of less than 2% per an um.