Glass Coatings, Energy Efficiency & Comfort

U-Value & Winter Insulating Performance

Insulation performance is measured to determine how effectively a window keeps heat in a room during winter conditions. Insulation performance is measured by U-Value and the LOWER the U-Value the better the window performs. See NFRC chart to the right and see how effectively our glass options perform compared to Double Pane Clear insulated glass.

Note: New 25C Tax Credit for 2023- Only Gilkey Ultra Triple Pane (Energy Star Most Efficient) will qualify.

Summer Solar Heat Control

Gilkey Windows can keep your home comfortable during warm summer months. You should select a window like our Gilkey LoE366 with Lower Solar Heat Gain Coefficient if:

  • Windows facing East or West
  • Large areas of glass
  • Want to reduce stress on Air conditioning equipment
  • Protection from Ultra Violet radiation
  • Upstairs rooms get excessively hot in summertime

Gilkey Insulated Glass Recipes :


a. LoE-366 Coating
b. 99.5% Argon Gas Fill
c. Endur™ Stainless Steel Spacer

LoE3-366® PLUS

a. LoE-366 Coating
b. 99.5% Argon Gas Fill
c. Endur™ Stainless Steel Spacer
d. LoE-i89 Coating

Triple-Pane LoE3-366® ULTRA

a. LoE-366 Coating
b. 99.5% Argon Gas Fill
c. Endur™ Stainless Steel Spacer
d. LoE-180® Coating

Gilkey Windows is Proud to Partner with Cardinal Glass

LoE3-366® Glass (Pronounced “Low E cubed 366”)

LoE3-366 Glass delivers the ideal balance of solar control and high visibility.
The ultimate performance glass. It just might make all other low-E glass obsolete. It provides the highest levels of year-round comfort and energy savings, making it the perfect glass no matter where you live. The secret? An unprecedented triple layer of silver. This is beyond ordinary, setting a new standard.


The World’s Most Advanced Stainless Steel Spacer System.
Patented corrugated shape and design improves sightline temperature which reduces condensation. Inorganic dual sealed for long term durability and peace of mind. No other glazing system compares.

High Performance Coatings


Enhanced Performing Glass.
A special coating of indium on the indoor light reflects heat back into the room thus lowering U-Values for better winter time comfort.


Ultra Clear Performance.
A single layer of silver LoE ideal for added insulation when used in conjunction with LoE3-366® or LoE2-270®. Allows for high visible light.

Neat+® Glass (Optional)

Naturally clean glass for windows that stay cleaner longer and easier.
Windows coated with Neat+® harness the power of the sun’s UV rays to loosen dirt so water can rinse it away leaving windows virtually spotless.