The U.S. Environmental Protection Agency’s (EPA) Energy Star program is working on a product specification for exterior and interior storm panels. The panels, also referred to as storm windows, are being specified more frequently in multifamily buildings in hurricane-prone regions.

EPA has released a framework document for consideration, which is now available for review and can be found here.

Beginning in 2009, exterior and interior storm panels with low-emissivity (Low-E) glass coatings became available commercially. When combined with other features that reduce air leakage, these new products provide better thermal performance than traditional storm panels.

For the storm window qualification, EPA wants to base the criteria on emissivity, solar transmittance (Tsol) and air leakage. EPA is not proposing the use of U-factor and solar heat gain coefficient as these metrics account for the energy performance of frame materials in addition to glazing materials. Emissivity and Tsol are glass-only properties, and EPA believes that these metrics directly distinguish higher-performing, energy-saving products from conventional products.

EPA says it may consider qualification criteria that have already been used by energy efficiency and/or utility programs as the basis for Energy Star qualification for exterior and interior storm panels. EPA cites two programs — Efficiency Vermont, which offered a pilot program in 2015 that provided discounted prices on qualifying low-E storm panel products at a limited number of retail locations, and the Regional Technical Forum (RTF) of the Northwest Power and Conservation Council, which added low-E storm panels as an approved measure in July 2015.

EPA will host a webinar to address questions and provide clarifications regarding the framework document on January 14. Framework document comments should be sent to Windows@energystar.gov by February 12, 2016, according to the agency.