Electrostatic Force Suspended-Air Multilayer (EPAM) Structure for Highly Transparent Energy Efficient Windows

TL;DR

This paper introduces an electrostatic force suspended multilayer window structure that significantly improves energy efficiency and transparency, offering a cost-effective retrofit solution for single-pane windows to reduce energy loss.

Contribution

It presents a novel EPAM structure utilizing corona discharge and contact electrification for controllable, stable suspension of polymer films, enabling highly transparent, energy-efficient windows at low cost.

Findings

U-factor lower than 0.5 Btu/hr/ft²/°F

Vt higher than 70%, haze below 1.6%

Cost less than $7.4/ft², 10 times cheaper than double-pane windows

Abstract

The poor thermal insulating building windows, especially single pane windows, are wasting ~7% of the total energy consumed by the U.S. every year. This paper presents an electrostatic force suspended polymer-air multilayer (EPAM) structure as a highly transparent and energy efficient window retrofitting solution for low-income single pane window users. To provide controllable and stable suspension force between large size compliant polymer films without deteriorating their visual transmittance (Vt), corona discharge (CD) was induced to permanently charge polymer films, leading to controllable permanent surface potential difference between two sides of CD charged films. Liquid-solid contact electrification (CE) was combined with CD to realize precise control of the surface potential of each side of polymer films. CD+CE treated films can obtain programmable and stable electrostatic forces to form resilient EPAM structures for cost and energy effective window retrofitting purpose. The resilient EPAM retrofitted windows can provide U-factor lower than 0.5 Btu/hr/ft2/{\deg}F, Vt higher than 70%, haze lower than 1.6% at cost lower than $7.4/ft2, at least 10 times cheaper than double pane windows. The energy saved by EPAM can reach as much as the order of 106 kJ/m2 per year. The CD+CE surface potential programming solution also provides a highly repeatable and controllable way for other electrical potential related technologies.