What happens when a building has a power outage?

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

What is the dynamic range of the glass?

The performance of SageGlass can range from 60% visible light transmission in its clear state, down to 1% in its tinted state, with a solar heat gain coefficient that varies from 0.41 on the high end to 0.09 on the low end. Learn how the dynamic range affects both light transmission and solar heat gain. These are the values for a typical double-glazed unit, but changes to IGU makeup, such as triple glazing, impact these values.

Where in the Insulated Glass Unit (IGU) is the SageGlass coating?

One unique element of SageGlass is that all of our IGUs are laminated. We apply the EC coating on a 2.2 mm annealed lite which is laminated with a PVB interlayer to whichever outboard lite is needed for the project requirements. Thus, the EC coating is on surface #4. This is important for a couple of reasons. First, on surface #2, we apply different coatings for aesthetic benefits. Second, it allows flexibility in outboard lite selection. Others in the EC industry apply the coating directly on the outboard lite. This precludes the use of aesthetic coating options, colored outboard lites and glass thickness to meet certain structural/wind load requirements. Our approach provides maximum flexibility.

Learn more. Visit our How Electrochromic Glass Works page.

What is the durability and longevity of SageGlass?

We bring the full expertise of Saint-Gobain, in both coated glass and IGU fabrication, to the SageGlass process. 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 products to pass the requirements for compliance to ASTM E-2141 (Standard Test Methods for Assessing the Durability of Absorptive Electrochromic Coatings on Sealed Insulating Glass Units). This test suggests that the performance of the product is barely impacted even under aggressive ageing tests, proving the longevity of the product.

How does electrochromic glass compare in terms of sustainability to other solar control solutions?

With the dynamic nature of smart windows, the facade can truly respond to the outdoors to be able to optimize to your building's energy goals. Because the glass has a very low SHGC value in its tinted state, it can prevent excess heat gain and reduce energy consumption from HVAC.  Dynamic glass also allows the facade to harness passive heat in climates with significant heat loads.


How is a SageGlass Insulated Glass Unit (IGU) installed? Are there installation limitations?

There are no significant limitations for installing a SageGlass IGU. While some care must be paid to the pigtail and frame cable, a SageGlass IGU is typically installed like any other in most common framing solutions. The SageGlass Field Operations team provides technical support to glaziers as needed.

What are smart windows?

Smart windows, sometimes called smart glass, maximize interior daylight, preserve views and maintain a connection to the outdoors which improves the experience and wellness of occupants.  Smart windows automatically tint and clear in response to sunlight to control glare and prevent heat gain, keeping spaces cool and comfortable.  Additionally, smart windows improve the energy efficiency of spaces, helping to reduce energy bills. 

Does SageGlass tint automatically or can I control it?

Both. SageGlass is designed as a fully automated system, optimizing daylight while controlling glare and heat. However, we're managing comfort, which is always subjective. For this reason, occupants are always given the ability to override the automation through some combination of a wall touch panel, our mobile app, or integration into a building management system (BMS). How manual control is integrated is customized to each project based on our customers' preferences.

How does electrochromic glass change its tint?

While SageGlass Maestro tells the glass when to tint and by how much, the "secret sauce" of how it tints is just as important. We coat SageGlass panes with five layers of ceramic materials for a total thickness of less than 1/50th 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. 

How does SageGlass technology work?

What we call "SageGlass" includes both the glass itself and its electronic controls. The brains of the operation is SageGlass Maestro, our proprietary, predictive control algorithm. Maestro knows where the building is in the world, the time of day, the date, the size of the glass, and the occupant layout. It then takes real-time sky readings, using a 360 rooftop sensor, to understand weather patterns and light levels. The algorithm then instructs the glass to get darker or lighter based on those variables.