Technology FAQs

Ready? We coat SageGlass panes with five layers of ceramic materials for a total thickness of less than 1/50^th that of a human hair. When voltage is applied across the coatings, ions travel from one layer to another layer, prompting a reversible solid-state change that causes the coating to tint and absorb light. In other words, the glass gets darker. Reversing the polarity of the applied voltage causes the ions to migrate back to their original layer, untinting the glass. Still curious? Find out more here.

We use a vacuum deposition process called “sputtering” to coat conventional float glass with layers of metal oxides. This is the same process used to make low-e and double low-e glass. The coated SageGlass pane is then paired with one or two more pieces of glass (clear, tinted or laminated) and one or two spacers to make a double-pane or triple-pane insulating glass unit (IGU).

Yes, with the SageGlass control system, you can select preset tint levels between the low and high ends of the glass’s dynamic range (less than 2 percent – 62 percent). You can also program the SageGlass control system to maintain a constant light level inside the space throughout the day. In this case, sensors integrated with the framing will tell the glass how to respond to changing light conditions outside.

SageGlass comes with a standard panel-mounted control system. You can operate it via a simple wall switch, our automation system, or a building automation system that is controlling lighting, energy use, audiovisual equipment and security. When integrated with a building automation system, you can control SageGlass windows, skylights and curtain wall elements by inputs from timers, light sensors, motion sensors, lighting control, thermostats and more.

Yes, when you integrate it with a building automation system, SageGlass adopts that system’s remote control capabilities.

It will take on average 3 to 5 minutes for the SageGlass pane to tint over 90 percent of its range in warm weather and direct sun, 5 to 10 minutes over the same range in moderate weather, and somewhat longer in colder weather in the absence of direct sun on the glass.

Yes, you can power our glass from a rooftop solar array or building integrated photovoltaics (BIPV) system just as they can power other devices. We have integrated SageGlass with photovoltaics in a project and are actively developing a tighter integration of PV-powered SageGlass IGUs. Solar power and SageGlass are obviously a beautiful match. SageGlass requires low DC voltage, and the power source (sunlight) is usually present when you want to tint the glass. So it all fits.

Total cost of ownership for SageGlass is generally equivalent or lower because in most installations, we eliminate the need for shading systems and the many associated costs. SageGlass also helps you reduce your energy costs (meaning smaller HVAC systems running less often). So while we may cost more when you compare us on a glass-to-glass basis, you’re looking at apples versus oranges.

The most important thing is the people factor. We don’t know how to quantify the many benefits of preserving the view and connection to the outdoors — which is the reason we put glass in buildings in the first place.

When power is removed, SageGlass reverts to a clear (untinted) state over a period of an hour or two.

The SageGlass Classic IGU can be varied from 62 percent visible light transmission  in its clear state down to less than 2 percent in its tinted state, with a solar heat gain coefficient  that varies from 0.48 on the high end to 0.09 on the low end. The performance of our five standard products is shown in this chart.

In most applications, it is on surface two (the inside surface of the exterior lite). In this location, the SageGlass coating blocks solar heat before it enters the building, meaning there’s significantly less heat for the HVAC system to cool.

By contrast, shades and blinds do not block heat from entering buildings through traditional windows. You might not feel heat directly if shades are drawn, but the heat still gets in and must be tempered by air conditioning.

SageGlass technology has undergone rigorous performance and durability testing by independent third parties, including the U.S. Department of Energy (DOE) and leaders in the glass fabricating and OEM skylight industry.  SageGlass IGUs were the first and only products to pass the ASTM E-2141-06 (Standard Test Methods for Assessing the Durability of Absorptive Electrochromic Coatings on Sealed Insulating Glass Units. In fact, the SageGlass technology survived over 100,000 cycles of accelerated environmental durability testing. That’s twice the test standard and equivalent to switching a window nine times per day for 365 days/year over a 30-year lifetime, according to the DOE’s National Renewable Energy Laboratory. Full details are available here.

Most frames that use hollow aluminum extrusions and wood window systems will accept SageGlass IGUs.  We recommend providing a 5/8-inch perimeter coverage on the glass, and sufficient room in the glazing pocket to accommodate the slimline snap-together connector.  SAGE has partnered with several leading window, skylight and curtain wall manufacturers for integrating SageGlass products into their framing systems. These companies are listed on our partners page. In addition, SAGE will work with suppliers chosen by the building owner, architect or contractor to develop solutions.