Kolbe demonstrates a commitment to providing accurate energy data by having products independently simulated, tested, inspected and listed in the NFRC certification program, and making that data available on our Energy Performance Search page and on window labels.
United States
ENERGY STAR® is a government-regulated program that was created by the Environmental Protection Agency (EPA), and the U.S. Department of Energy (DOE), to help consumers quickly and easily identify energy saving products. The ENERGY STAR program uses energy values obtained by window and door manufacturers through the National Fenestration Rating Council (NFRC) program. NFRC ratings are based on the energy performance of the total window or door – both glass and frame
The ENERGY STAR program for the United States divides the nation into four separate climate zones – Northern, North-Central, South-Central, and Southern. The performance criteria that needs to be met in order to be ENERGY STAR compliant in specific climate zones are shown in the charts provided. Note that this information is per criteria that took effect in 2023.
California's Title 24
Kolbe has windows and doors that can meet the strict California Title 24 Building Energy Efficiency Standards. Contact us or talk to your dealer about our products with glass options that help meet these stringent energy efficiency requirements.
ENERGY STAR – Qualification Criteria for Windows*
CLIMATE ZONES – U.S. | U-FACTOR | SHGC |
Northern** | ≤ 0.22 | ≥ 0.17 |
Northern** | = 0.23 | ≥ 0.35 |
Northern** | = 0.24 | ≥ 0.35 |
Northern** | = 0.25 | ≥ 0.40 |
Northern** | = 0.26 | ≥ 0.40 |
North-Central | ≤ 0.25 | ≤ 0.40 |
South-Central | ≤ 0.28 | ≤ 0.23 |
Southern | ≤ 0.32 | ≤ 0.23 |
*The effective date for the Northern Zone prescriptive and equivalent energy performance criteria for windows was September 7, 2023. North-Central, South-Central, and Southern criteria will also follow 2023 guidelines.
**Northern zone windows can meet prescriptive (1st row) or alternative energy performance (2nd, 3rd, and 4th rows) criteria to qualify for ENERGY STAR.
ENERGY STAR – Qualification Criteria for Doors
GLAZING | U-FACTOR | SHGC |
Opaque | ≤ 0.17 | No rating |
≤ 1/2-Lite | ≤ 0.23 | ≤ 0.23 |
> 1/2-Lite | ≤ 0.26 | Northern and North-Central ≤ 0.40 |
> 1/2-Lite | ≤ 0.28 | Southern and South-Central ≤ 0.23 |
Related Links: U.S. Climate Zones | NFRC Database | Interpreting the NFRC Label
Canada
ENERGY STAR – Qualification Criteria for Windows & Doors in Canada*
MINIMUM ENERGY RATING (ER) | or | MAXIMUM U-FACTOR/MINIMUM ER |
34 | or | ≤ 0.21 |
*Criteria shown applies to windows, sliding doors, and swinging doors
U-Factor Equivalency – Qualification Criteria for Windows & Doors in Canada*
IMPERIAL | METRIC |
0.35 | 2.00 |
0.32 | 1.80 |
0.28 | 1.60 |
0.25 | 1.40 |
0.21 | 1.20 |
Related Links: ENERGY STAR qualified products in Canada: Windows | Doors | Door Sidelites & Transoms
