What is ISO 18543- Electrochromic glazings about?
ISO 18543 specifies the accelerated ageing test and requirements for electrochromic glazings intended to either control direct or indirect solar transmission, or both. The electrochromic glazings can be assembled as insulating glass units, laminated glass, or a combination of both.
The test method described in ISO 18543 is only applicable to chromogenic glazings that can be switched between different transmission states using an electrical stimulus. This test method is applicable to any electrochromic glazing fabricated for use in buildings such as indoors, windows, skylights, exterior wall systems and glazing exposed to solar radiation.
Who is ISO 18543- Electrochromic glazings for?
ISO 18543 on the accelerated ageing test and requirements for electrochromic glazings is useful for:
- Electrochromic glazings manufacturers
- Glass manufacturers
- Design engineers
- Builders
- Quality control personnel
Why should you use ISO 18543- Electrochromic glazings?
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.
ISO 18543 is intended to provide a means for evaluating the durability of electrochromic glazings
ISO 18543 provides you with the 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, which are realistic for the intended use of electrochromic glazings. ISO 18543 helps you manufacture high-quality electrochromic glazings.
What’s changed since the last update?
BS ISO 18543:2021 supersedes BS ISO 18543:2017, which is withdrawn. BS ISO 18543:2021 includes some technical changes with respect to BS ISO 18543:2017. These include:
- The document has been restructured
- The acceptance criteria for the two classes have been revised
- Fast switching products have been taken into account
- The concept of photopic transmittance ratio has been abandoned in favour of the one of 85 % of the dynamic range
- Other types of lamps have been allowed provided that they simulate correctly the solar irradiation

