The big headline is that U-Factor requirements are much more stringent under ENERGY STAR® version 7.0. In the Northern climate zone, triple-pane glass is now the best solution for meeting requirements. We’ll share the highlights related to version 7.0 and give you some tips about specifying product for your climate zone.

One unique aspect of meeting ENERGY STAR criteria for windows in the Northern zone is that there are two options to qualify: a primary prescriptive path or an equivalent energy performance path. Again, only the Northern climate zone allows two options and only for windows. Patio doors (> ½ lite category) in the Northern zone must follow the prescriptive path.

The prescriptive path means the window product must meet a U-Factor value that’s ≤ 0.22 and an SHGC value that’s ≥ 0.17. The second path, the equivalent energy performance path, allows for a higher U-Factor if there’s a higher SHGC to go along with it — see the window criteria table above for exact values.

How to specify product certified to ENERGY STAR 7.0 criteria

There are many factors that go into specifying the right product, but here are a few tips for choosing a product that is certified to ENERGY STAR version 7.0 criteria:

Northern zone: Remember, there are two paths to compliance, so there’s some flexibility to choose a product with higher U-Factor if it’s balanced by SHGC. Generally though, the simplest path to compliance will be with a triple-pane product.

• All windows in the A-Series product line can be ordered with triple-pane glass, so this product line will offer the most options.
• The 400 Series offers triple-pane windows in the Northeast and the option for a factory-applied energy performance panel on the Tilt-Wash Double-Hung Window, which can meet requirements when combined with the right Low-E coatings. 
• For patio doors, triple-pane glass is available with the A-Series, 400 Series, and 200 Series product lines. 

North-Central, South-Central, and Southern climate zones: Generally, requirements for these zones can still be met with dual-pane window and door product coated with SmartSun™ glass and HeatLock® technology. This combination of coatings insulates while reducing SHGC.