Two huge new studies reveal interesting insights regarding electrochromic windows
Electrochromic windows are a technology that has been around for many years, but has so far failed to gain widespread adoption. The concept is relatively straightforward: the windows are placed on south-facing or other sunny locations and the tint level is electronically adjusted either automatically or by the building occupants. These windows can offer several advantages, including lower heat gain (and thus lover air conditioning bills) on hot days, less glare, and the ability for building owners to remove blinds so the occupants are always able to have a view.
The GSA’s Green Proving Ground has just posted two major electrochromic window evaluations to their website, conducted in Portland and Sacramento.
In Portland, respondents liked the windows compared with blinds that totally obstructed their views (though the switching time between settings was bothersome), the EC windows led to increased thermal comfort (though a dysfunctional HVAC system caused issues), energy savings were “modest”, and payback periods ranged from 10-30 years, depending on various scenarios.
In Sacramento, occupants had mixed emotions regarding the aesthetics and reported slightly greater thermal comfort during hot weather. Lab testing found HVAC energy reductions but an increase in lighting demand (the windows were tending to overtint for part of the evaluation). No payback period is given for the Sacramento project.
Overall, the GSA determined that while the technology is relatively mature, the applications are still limited.
You can find the entire reports, as well as summary documents here.