The U.S. Environmental Protection Agency is seeking public comments on draft 2 of the 7.0 Energy Star residential window, door and skylight standards. The most recent version of the new standard is meant to bridge the needs of glass industry stakeholders and the increasing need for more energy-efficient design, especially in hotter southern states.
EPA analyst Doug Anderson explained the agency’s proposed changes to the Energy Star standard at the 2022 Fenestration and Glazing Industry Alliance Hybrid Annual Conference. Anderson manages the Energy Star Residential Window, Door and Skylight Program, the Energy Star Most Efficient Program for Residential Windows, and the "Seal and Insulate with Energy Star" program. He spoke on March 2 in Florida to FGIA members in-person and virtually via webcast.
Energy Star's 7.0 ‘Draft 2’ Updates:
- Adjust trade-off values for the Northern Zone based on a new energy analysis.
- Revise sliding patio door criteria and full-lite swinging door criteria to “meet in the middle,” in response to comments from stakeholders.
- Set the effective date for version 7.0 criteria to begin 12 months after it is finalized
- Adjust some climate zones to better align previously proposed county “islands” with surrounding areas of California, North Carolina and Virginia (12 counties).
Draft 1 standards saw promising energy savings, especially in southern states
“We are looking at double-pane and triple-pane performance,” Anderson said. “Our draft 1 of version 7.0 window specification proposal reduces U-factor and solar heat gain coefficient in the southern U.S.” In version 7.0, he said, climate zone maps are adjusted to reflect counties across the U.S. that moved into different International Energy Conservation Code zones.
Public comments on the first draft questioned the EnergyPlus energy modeling software. “It took a while to hone the analysis and get it right,” he said. The Lawrence Berkeley National Laboratory offered to rerun the analysis so all could better understand the energy and cost distribution, he added.
“We actually saw much better results in the South. Draft 2 saw reduction of U-factor to improve insulation power and reduction in SHGC in Southern U.S. to reduce heat gain,” Anderson said.
New windows drive up home value
Anderson said many factors are at play right now that impact manufacturing, including inflation and supply chain issues, yet one thing remains constant. “Windows have a great payback,” he said. “If someone puts new windows in and sells their house, they are going to get a lot of that money back.”
The EPA sought feedback on applying window criteria to full-lite sliding patio doors in the Energy Star Discussion Guide. "We found patio doors with a large area lite with a frame are more like windows in design, match the look and feel with windows and use similar glass packages as windows," he said.
Public comments on draft 2 specifications are due March 28, with a final draft tentatively due in May or June of 2022. “The EPA hopes to finalize a report in June or July, with an effective date one year later,” Anderson said. “Companies are all over the spectrum. Some are ready to go. Others have many certified options that could get the version 7.0 numbers. We feel one year is reasonable.”