Prismatic Window Films

Prismatic Window Films

Prismatic window films are made through embossing, with surface textures of depths between 10 nanometers up to 200 microns. They are manufactured in a cleanroom environment via roll-to-roll processes with widths that are applicable to large-area windows (e.g., 2 meters). LBNL researchers collaborate with industry to develop, characterize, simulate, and field test new materials that have the potential to displace lighting energy use up to 40 feet from the window.

Prismatic window film in 71T

A thin microprismatic window film redirects daylight to the ceiling plane in the LBNL Advanced Windows Testbed, helping offset electric lighting energy use during the day.  Industry prototypes evaluated via simulations and field tests have the potential to reduce annual lighting energy use by 38% (compared to ASHRAE 90.1-2007) across a 40 foot deep open plan office zone with a 3% occurrence of glare.