How it Works

When the sun shines against windows, a large amount of thermal energy is transmitted inside the building, heating the atmosphere inside and causing “solar heat gain”. 

• Solar heat gain coefficient (SHGC) is the amount of heat transmitted by a window. 
• The more windows a building has the greater its SHGC. 
• Higher SHGC windows require large air-conditioning and HVAC systems to counteract solar heat gain. 
• Up to 38% of building’s total energy consumption is for air-conditioning to counteract solar heat gain. 

Some buildings have low-e windows installed to block out the heat caused by the invisible near infra-red light coming from the sun. However these windows do not deal with the nearly 50% of solar heat gain that comes from the sun’s light that is in the visible spectrum.

• Smart windows made with SWITCH's photochromic/ electrochromic film  darken when exposed to sunlight to dynamically reduce SHGC and glare while preserving views and taking advantage of natural daylight. 
• The film can be 'switched' in low light conditions by the application of a small electric charge and the tinting disappears, allowing occupants to optimize their lighting environment.