Smart Windows are a Smart Idea

February 12, 2016 By Carl Weinschenk

smart-window

Fenestration – roughly stated, the art of bashing holes in the sides and tops of buildings and putting various objects in those holes in an energy-efficient manner – is a big deal. Windows fill many of those holes, and smart glass is a big advance.

The savings can be significant. Dr. Helen Sanders, the Vice President of Technical Business Development at SageGlass, cited a study that found that under the right conditions, the transition from plain to intelligent glass in all the commercial window building stock in the United States would save about 3 quads of energy. That’s impressive: Overall, she said, all the commercial buildings in the United States use 20 quads of energy annually. She said that a typical building using intelligent glass likely would reduce its energy consumption about 20 percent annually.

But, at the same time, the category is complex and must be deeply understood before those gains can be realized. “Smart glass windows can be broadly classified into two major types – electrically activated and environmentally activated,” Technavio Research Analytst Soumya Mutsuddi told Energy Manager Today. “Electrically activated smart windows are also known as active windows and require electric supply for their functioning. They can be further segregated into Electrochromic, Liquid Crystal and Suspended Particle smart windows.”

The distinctions cut even deeper. “Environmentally activated smart windows, also known as passive windows, do not require electric supply as they depend on natural sunlight for their functionality,” Mutsuddi wrote. “They can be further segregated into Photo-chromatic, Thermo-chromic and Thermo-tropic windows. While most vendors offer the two major types of smart windows, they are also engaged in R&D to identify and develop new technologies and solutions for smart windows.”

Despite the complexity, the bottom line is fairly simple: Windows are deeply enmeshed in building energy patterns and the explosion in technology that has rocked the world during the past two decades opens up great possibilities to change the equation in a positive manner. People are paying attention. In a report released last month, Technavio said that the worldwide smart glass market is set to grow at a compound annual growth rate (CAGR) of 21.13 percent from 2016 to 2020.

The non-residential sectors will play a big part of that growth, according to Brett Murray, the Vice President of Marketing for View Dynamic Glass. “The category is growing rapidly, with commercial and industrial sectors growing at an incredible clip,” told Energy Manager Today. “Many people are looking for ways to increase the percentage of glass used throughout the building envelope to admit ever more natural light, yet energy efficiency regulations (such as California’s Title 24) are making this harder to achieve. As studies emerge that daylighting and connection to the outdoors is important for people across a number of settings – healthcare, education, workplace, etc. – owners and architects are looking for ways to deliver those benefits to their occupants.”

Murray, who said smart glass can be employed in both new-build and recommissioning projects, offered advice to those considering projects. Among other things, he counsels building managers and other decision makers to understand the level of control individuals will have over their windows, how much support management will need to provide to optimize the windows and derive the full benefit. He mixes normal due-diligence steps with smart glass-specific ideas:

  • Will the glass function in extreme temperatures?
  • What unique challenges does the project pose?
  • What are the largest sizes the windows can be supplied in that meet the program requirement?
  • Does the technology impact aesthetics?
  • How complex is the network controlling the windows?
  • Is remote control possible?

Sanders added that the advent of these advanced options will impact building design which, in turn, will change how building managers operate. “ They will be able to put more windows in a building without take an energy hit,” she said. “They also will have fewer orientation concerns, such as being careful about west-facing glass, for example,” she said.

He bottom line clearly is that there are advantages to use of smart glass. But folks who run buildings shouldn’t be fooled: Turning an inert object into one that is actively controlled and transitioned – perhaps multiple times per day – is significant. It should not be taken lightly, and partners must be chosen carefully. “The installation and maintenance of smart glass windows is a complex and expensive process, which may require skilled technicians,” wrote Mutsuddi. “Hence, it makes sense to enquire about the installation and after sales services offered by the vendor to minimize the chances of problems post purchase.”

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