Choose Between Wellington's Two Families Of Insulating Glass

R-Value measures resistance to heat flow. The higher the number, the better.

U-Value measures heat transmission through building materials. The lower the number, the better.

Low E glass employs a micro thin heat reflective layer in the glass which is designed to reflect radiant heat away from the window and reduce fading caused by harmful UV rays. Glass U-Values range from .34 - .26 depending on which gas is sealed between the glass. Low E is compatible with all of our Decorative Glass Options.

R 2.9 Low E with Air fill
U-Value .34

R 3.2 Low E with Argon gas fill
U-Value .31

R 3.9 Low E with Krypton gas fill
U-Value .26

Heat Mirror™  glass employs a suspended heat reflective coated film in the middle of the air space between the glass and gives the ultimate performance for both thermal and sound insulation. Glass U-Values range from .24 - .13 depending on which gas  is sealed in both air spaces. Because the Heat Mirror film resides in the middle of the air space, it is only compatible with our Overlay and Regal Cut glass Decorative Glass Options.

R 4.2 Heat Mirror with Air fill
U-Value .24

R 5.6 Heat Mirror with Argon gas fill
U-Value .18

R 7.7 Heat Mirror with Low E and Krypton gas fill
U-Value .13