The Attachments Energy Rating Council (AERC) has certified six new commercial secondary window systems — four interior storm window products from Larson Manufacturing, two interior and two exterior products from Quanta, and two window insert products from Indow Windows.

AERC launched the Commercial Secondary Window program late last year alongside its existing residential products certification program. AERC recognized the potential of secondary windows and prioritized the development of a commercial rating and certification program in order to provide the industry with credible data on the energy performance of these products. The commercial secondary windows program adopted similar, rigorous performance metrics used by AERC’s residential program including U-factor, solar heat gain coefficient (SHGC), visual transmittance (VT), and air leakage.