WINDOW FILM: Reduces HVAC Cost, Enhances Indoor Air Quality &
Improves Appearance

Up to 40% of a building’s cooling requirements are from heat entering
windows. As a supplement to HVAC, stopping heat at the windows using
window film can reduce air conditioning operating frequency and cost.  
Window film was invented to reduce temperatures in overheated
buildings. Too much solar energy entering windows increased heat,
making occupants uncomfortable and air conditioning more expensive to
operate.

Today we’ve are facing to improve energy conservation and include
dealing with stale air, moisture and mold growth, out-gassing of furniture
and building components and the impact of such conditions on the
productivity and well- being of building occupants. Ironically, many of the
measures taken to increase energy efficiency such as “tightening”
buildings to reduce both air infiltration and outflow have contributed to
negative indoor environmental quality. Adding to the management
challenge, sensitivity to preserving historic and community character
sometimes conflicts with measures to increase energy conservation and
enhance environmental standards.


At Stanford University's Encina Hall, about 6,212 square feet of spectrally
selective window film was applied in June 2003. Spectrally selective film
blocks solar heat while transmitting high levels of natural light.
Daily air conditioning (A/C) requirements to remove heat at Encina Hall
prior to the film's installation amounted to 665.57 A/C tons at an A/C cost of
$66.56 per day. Daily air-conditioning requirements to remove heat with the
film installed are 339.44 A/C tons at an A/C cost of $33.94 per day. As a
result of the film's installation, Encina Hall is seeing an annual savings in
A/C cost of $4,891.95. Source: California Energy Commission