Electrochromic glass, also called smart glass, is a dynamic glazing technology that changes tint electronically to control solar heat transmission and visible light transmittance on demand. When voltage is applied, ions move through an electrochemical layer, causing the glass to darken from clear to opaque without requiring external shades or blinds. This allows real-time management of solar gain and glare.
Technical Details
Electrochromic windows can shift from approximately 60 percent visible light transmittance to 2 percent in 15 to 30 seconds, reducing solar heat gain coefficient from 0.40 to 0.10. Power consumption is minimal, typically 1 to 3 watts per square meter during transitions, with no ongoing power draw when tint is stable. Systems integrate with building automation for coordinated control based on occupancy, time of day, and exterior light levels.
Practical Significance
Electrochromic glazing reduces cooling loads by 15 to 30 percent in perimeter zones, decreasing HVAC equipment capacity and operating costs. While currently 3 to 4 times more expensive than standard glazing, costs decline with market growth. Smart glass improves occupant comfort by reducing glare and heat, extends window product life, and provides security through privacy control.