Thermal Insulating Polymer-Air Multilayer for Window Energy Efficiency

TL;DR

This paper introduces a polymer-air multilayer (PAM) coating that significantly improves window energy efficiency by reducing heat transfer through glass panes while maintaining high optical transparency.

Contribution

The study presents a novel PAM structure that combines multiple polymer films and air gaps to enhance thermal insulation and optical properties for window retrofitting.

Findings

U-factor reduced from above 1 to 0.5-0.6 Btu/{{h}{ft}^2{{ extdegree}F}}

High optical transmittance (>70%) with low haze (<2%)

Effective in decreasing conductive, convective, and radiative heat transfer

Abstract

Polymer-air multilayer (PAM) was developed to decrease the heat loss through window glass panes. 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 visual transmittance of PAM is higher than 70%, and the haze is less than 2%. PAM not only has mechanisms to reduce the conductive and convective heat transfer, but also can obstruct the radiative heat transfer. With a 4~6 mm thick PAM coating, the U-factor of a glass pane can be lowered from above 1 Btu/{{h}{ft}^2{{\deg}F}} to 0.5~0.6 Btu/{{h}{ft}^2{{\deg}F}} .PAM is resilient and robust, relevant to the window retrofitting applications.