lectrochromic glasses (also known as smart windows) are materials that change their transparency or color in response to an applied electric voltage. These glasses are widely used in architectural, automotive, and energy-efficient applications, offering dynamic control over light transmission and heat management. The "range" of electrochromic glasses typically refers to the extent to which these glasses can change their optical properties (e.g., transparency, reflectance, or color) and how they perform in various settings.
Here are some key aspects of the range of electrochromic glasses:
1. Optical Transmission Range:
- Transmittance Range: Electrochromic glasses can vary the amount of visible light that passes through them, depending on the voltage applied. Typically, electrochromic glasses can range from near 90% transmittance (clear) when fully transparent, down to around 5-10% transmittance (tinted or opaque) in their darkest state.
- Clear State: In the "clear" state, these glasses are highly transparent, allowing most visible light to pass through (often 80%-90% or more).
- Tinted State: When the voltage is applied, the glass becomes tinted, blocking a significant portion of visible light (often down to 10% or less). This is useful for reducing glare and controlling solar heat gain.
2. Color Range:
- Electrochromic glasses can shift in color as well as transparency. Typically, these glasses transition from clear to a tinted state that can appear blue, gray, bronze, or even green, depending on the specific electrochromic material used.
- Color Shifts: The color change is usually subtle and may vary from one electrochromic product to another, but the general shift is from a neutral clear state to a darker shade.
3. Spectral Range (Infrared and Ultraviolet):
- Infrared (IR) and UV Blocking: Electrochromic glasses are often engineered to not only affect visible light transmittance but also to provide shading in the infrared and ultraviolet parts of the spectrum. This allows these windows to also block out significant amounts of solar heat (infrared radiation) while preventing harmful UV radiation from entering.
- Depending on the electrochromic material and coating, some glasses can block over 50% or more of the solar heat (IR) without compromising on visible light transmittance.
4. Switching Speed and Durability:
- Switching Range: The range of time it takes for electrochromic glasses to transition between clear and tinted states can vary. Some advanced products switch in just a few seconds, while others may take longer (30 seconds to a few minutes) depending on the system design and size.
- Long-Term Durability: The range of durability, which determines how many cycles (clear-to-tinted and back) the electrochromic glasses can undergo before degradation, can vary. Some products can last for decades, with minimal performance degradation, while others may have shorter lifespans.