Over 200 electrochromic (EC) windows have been installed in Portland’s 911 Federal Building as part of a test installation for the GSA’s Green Proving Ground (GPG) program. They are expected to reduce HVAC and lighting energy use by 20% while giving building occupants continuous, unobstructed views to the outdoors.
EC windows use a small electric current to automatically tint based on the amount of daylight detected. Using predictive algorithms, the glass transitions through four tint levels to control glare and solar heat gain without the use of blinds.
The dynamic windows are placed on the south side of the building’s upper floors that receive the most heat and glare. Through the end of 2015, Lawrence Berkeley National Laboratory will evaluate the effectiveness of the tinting capability and compare the performance against existing windows with blinds.
The 911 Federal Building already has a strong sustainability profile. The eight-story facility was constructed in the 1950s and was the first GSA property to earn Platinum certification under LEED for Existing Buildings. It features a vegetated roof, uses advanced metering equipment, and has an ENERGY STAR rating of 96.
This is the first study on dynamic windows conducted in the Pacific Northwest and will add to data already gleaned from sites in Texas and California.
The purpose of the GPG program is to conduct real-world evaluations of emerging building technologies on federal assets in order to absorb risk from the private sector.