A “smart window” automatically adapts to the outdoor air temperatures, which reduces the need for heating and cooling. In hot weather, the smart windows become tinted reflect light and heat. In cool weather, the windows become transparent to let the light and heat inside.
Therefore, smart windows can boost a building’s energy efficiency, which will reduce its energy costs. For building projects pursuing LEED certification, they can also contribute to Energy and Atmosphere credits.
The following are three types of smart windows that are on the market or scheduled for release in Spring 2012.
1. RavenWindow from RavenBrick
Founded in 2007, RavenBrick is a Colorado-based company that develops smart construction and window materials using clean nanotechnology.
RavenBrick released its signature product, the RavenWindow, to the market in the second quarter of 2012.
RavenWindows (pictured) can cut energy bills by more than 30%. In fact, RavenBrick claims that they are the most energy efficient windows in the world.
RavenWindows are easy to install either during or after construction – so they are ideal for both new construction and retrofits.
2. SageGlass from Sage Electrochromics
Founded in 1989, Sage Electrochromics considers itself the world leader in electrochromic glass, or smart glass, for the building industry.
SageGlass is an electrochromic, or electronically tintable, glass that can be switched from clear to darkly tinted at the click of a button or programmed to respond to changing sunlight and heat conditions.
According to the company, SageGlass has the potential to cut commercial building cooling loads by up to 20%, lighting costs by up to 60%, and the size of the HVAC system by up to 25%.
Unlike RavenWindows or Soladigm, SageGlass windows and skylight systems are already available on the market.
3. Soladigm Dynamic Glass
Founded in 2006, Soladigm, a venture-backed company based in Militas, California, develops “next-generation” energy efficient building solutions.
Soladigm’s Dynamic Glass, expected for release in spring 2012, is an electrochromic, controllable smart window that can change from clear to dark tint on command. According to the company, this controllability results in 25% reduction in HVAC energy consumption and 30% reduction in peak load.
LEED Credit Overview
Since smart windows boost a building’s energy efficiency, they could contribute to points in the LEED Energy and Atmosphere (EA) credit category. According to the LEED for New Construction 2009 rating system, they may contribute to the following credits:
• EA Prerequisite 2: Minimum Energy Performance (0 points)
This credit establishes a minimum level of energy efficiency for buildings. Since smart windows can cut a building’s energy bills, they can help to achieve this prerequisite.
• EA Credit 1: Optimize Energy Performance (1-19 points)
This credit rewards LEED projects for achieving energy efficiency beyond the minimum set forth in EA Prerequisite 2. Points are awarded based on the energy cost savings percentage – the higher the percentage, the greater the number of points awarded. Again, energy efficient smart windows can help to achieve this credit because of it’s energy saving features.
Depending on the windows and their design, they could also contribute to credits such as Indoor Environmental Quality (IEQ) Credit 8, Daylight and Views and IEQ Credit 6, Controllability of Systems.
A recent graduate of Cornell University, where she studied Environmental Science and concentrated in Sustainable Development. Her interest in green building and LEED stems from her project-based coursework at Cornell, where she proposed design strategies for sustainable developments in Helena, MT and Ithaca, NY. Claire also exercised her passion for sustainability and energy conservation through extracurricular activities at Cornell, such as Solar Decathlon, Lights Off Cornell and Sustainability Hub. For the last three summers, she worked on energy projects at a town government, including an on-site hydrogen station and EECBG-funded activities.