The U.S. Environmental Protection Agency’s (EPA) Energy Star program recently hosted a webinar to address questions and provide clarifications regarding a product specification for exterior and interior storm panels, also called storm windows. The storm windows are used in both multi-family and single-family residential buildings.
Energy Star is considering a specification for storm windows because many of these products are now glazed with low-E glass. Research conducted by the Lawrence Berkeley National Laboratory and the Pacific Northwest National Laboratory (PNNL) shows that low-E storm panels can reduce heating and cooling energy use by 5 percent to 14 percent over clear glass storm panels.
Brian Booher, technical lead at D+R International Program, said the proposed scope of the specification covers exterior and interior storm panel products that are intended for use in residential dwellings, including multi-family buildings.
“The Energy Star program applies to individual products, and it is up to the consumer where they are ultimately installed,” he said. “Products will be considered individually by a certification body to determine if they meet the eligibility requirements. For example, if an apartment building or hotel wanted to install a customized storm window system, those products may not be eligible for Energy Star certification under the current proposal. Curtainwall retrofits and similar commercial-scale projects would fall outside the scope as they are not intended for residential use.”
PNNL projects storm panels are installed in half a million homes annually, but only about 10 percent currently use low-E glass. According to the webinar, it’s because there is lack of recognition by energy rating and certification systems.
Affordability is a key benefit of storm windows with low-E glass — they have an expected incremental payback of about five years or less.
According to the webinar, the specification would not cover exterior storm panels without weep holes or other features that allow moisture to drain from between the storm panel and primary window; partial components of exterior or interior storm panels; storm doors or door inserts; and other related fenestration attachments, including window films, curtains, blinds, shades, shutters, awnings and jalousie windows.
Energy Star has released a framework document regarding the storm window specification. It can be found here.