The International Organization for Standardization has published a new standard that specifies the accelerated ageing test and requirements for electrochromic (EC) glazings.

According to the introduction section of the standard, ISO 18543:2017, it is intended “to provide a means for evaluating the durability of electrochromic glazings.”

The test procedures covered in the document include: a “rapid but realistic cycling between high and low light transmission states” and “environmental parameters that are typically used in weatherability tests,” such as simulated solar exposure and high temperature.

According to the standard’s scope, the test method only applies to glazings that can be switched between high- and low-transmission states using an electrical stimulus. It doesn’t include thermochromic or photochromic glazings, which do not respond to electrical stimulus.

“This test method is applicable to any electrochromic glazing fabricated for vision glass (e.g. insulating glass unit, laminated glass) for use in buildings such as doors, windows, skylights and exterior wall systems and glazing exposed to solar radiation,” the scope reads. “The layers used for constructing the EC glazing and for electrochromically changing the optical properties can be inorganic or organic materials.”

The document notes that electrochromic glazings perform several important functions in a building envelope, including: minimizing the solar energy heat gain; providing for passive solar energy gain; controlling a variable visual connection with the outside world; enhancing thermal comfort (controlling heat gain), energy efficiency performance, illumination, and glare control; and providing for architectural expression.

“Therefore, it is important to understand the relative serviceability of these glazings,” it reads.

The 14-page standard was published in September through the ISO/TC 160/SC 1 Glass in Building technical committee.