Improved Window Energy Efficiency With Thermal Insulating Polymer-Air Multilayer

Polymer-air multilayer (PAM) was developed to reduce the heat loss through windowpane. A PAM consists of a few polymer films separated from each other by air gaps. Thanks to the excellent optical properties of the polymer films, the visible transmittance of PAM is higher than 70%, and the haze is similar to 1.8%. PAM not only has mechanisms to reduce the conductive and convective heat transfer, but also can obstruct the radiative heat transfer. By mounting a 6 mm-thick 4-layer PAM on the indoor side of a glass pane, the overall U-factor is lowered from 5.8 W/(m(2).K) to 2.85 W/(m(2).K). PAM is resilient and robust, attractive for the window retrofitting applications.