Dynamic electrochromic glass offers the best of all worlds, from energy efficiency to maximized outdoor views and glare elimination, according to View Inc. sales director Jeff Kersten. Kersten led the company’s latest AIA-approved webinar yesterday, and suggested that dynamic electrochromic glass facades, which use a low electrical signal to change the color or transparency of the glass throughout a given day, present new opportunities to marry architectural aesthetics with energy efficiency.
“As we’ve progressed over time, we’re creating buildings with more and more glass,” Kersten noted.
That trend, he said, is largely due not only to contemporary aesthetic preferences with respect to building exteriors, but to the general acknowledgment of the need for a connection with the outdoors.
Yet, he noted, there’s a tradeoff with glass—namely, glare at certain times of day as well as energy issues. That beautiful view, therefore, normally comes with a compromise. It doesn’t have to be that way anymore, said Kersten.
The technology behind electrochromic glass is not new, according to Kersten. It’s been around for some four decades; however, only recently has dynamic glazing been commercially applied for architectural purposes. Electrochromic technology involves a solid-state coating with nano-layers of metal oxides, allowing for the use of low electrical voltages to change the glass from clear to tinted and back again.
The increments of change can be made through a few different means. First, the windows are automatically programmed based on the latitude and longitude of the building location, allowing them to react appropriately to the position of the sun throughout the day. In addition, an automated override can make changes to windows based on a given day’s actual conditions (partly cloudy, full sun, etc.). Building occupants also can have access to a wall switch or even a smart-phone app that can make adjustments to the windows. Pre-set scheduling to accommodate personal preference, much like a smart thermostat, is also an option. Finally, windows can be adjusted on the spot, in real-time, akin to—yet much more effective then—adjusting the angle of blinds.
The result, Kersten says, is an all-day, unblemished visual connection to the outdoor environment that humans crave and need. Better still, the windows are continually adjusting to reduce unwanted heat and energy loss, resulting in significant savings for the building, he said.
Materials used are inorganic, making the technology extremely durable, said Kersten. Testing by the National Renewable Energy Laboratory suggests the technology lasts at least 50 years and likely longer (based on an average of three switching times per day).
Of course, it’s electricity that’s powering this compelling technology throughout the day. Doesn’t that eat up the energy savings garnered from the windows? “The good news is, dynamic glass will save you more power than you will ever consume,” he said.
That notion certainly bears out in the numbers he presented. Under one case study, a 400,000-square-foot, 20-story office high-rise achieved energy cost savings in the neighborhood of 20 percent. The technology delivered 11 percent savings on operational costs at a two-story school, while a skylight project earned a payback in HVAC savings of 35 percent. Moreover, Kersten points out that numerous studies have shown the importance of natural light and access to outdoor views to productivity and mood. With dynamic glass, shades never have to shut when the sun is glaring—and the 2 p.m. doldrums hit an office worker.
Thus, electrochromic glass provides architectural freedom, energy efficiency, connection to the outdoor environment, and a more pleasant indoor experience (no glare, no hot spots, nicer view) all in one package, according to Kersten.
“What we believe is, with dynamic electrochromic glass, you can actually have the best of all worlds,” he said.