DOE OSTI2019
Windows in residential buildings are estimated to generate 29% of all HVAC heating and cooling load, approximately 2.67 quadrillion Btu (Apte and Arasteh 2006). Although more than a third of residential windows are single pane, very few utility programs offer incentives for installation of energy-efficient windows (Bickel et al. 2013). The reason is simple: unless someone is already planning to replace their windows, the payback can often take a decade, if not longer. Preliminary data indicates that some energy-efficient window attachments, such as low- emissivity (low-e) storm windows and interior panels, cellular shades, interior and exterior roller shades and shutters, window films, solar screens, window quilts, and awnings, can deliver cost-effective energy savings. Additionally, the means to reliably identify and compare energy-efficient window attachment products will soon be available through the Attachment Energy Rating Council (AERC), a public interest energy performance rating and certification organization co-funded by the U.S. Department of Energy (DOE) and the window attachment industry. This paper presents, for the first time, national and regional energy savings estimates for cellular shades and low-emissivity storm windows and panels using existing data on household energy savings potential. This paper is an early step in the process of determining the cost-effectiveness of window attachments for utility programs. The next step is for utilities to develop pilot programs to conduct field tests of these products, which will generate the energy savings data to determine if full-scale programs are cost-effective.