Over the last thousand years, windows have seen significant advancements, much like most other homebuilding materials. From paper to transparent animal horns, our predecessors used various materials to make windows. There is proof that windows in Egypt under Roman rule were made of glass circa 100 A.D. Glass windows, back then, weren’t as clear as one would expect, but they were still advanced as compared to other materials, so their destiny was sealed.
As glass production technology advanced, so did window design. For various purposes and climates, several framing and glazing techniques were created. Wood, metal, vinyl, fiberglass, and composite materials have been used as framing materials for years. Each has a different level of thermal and structural performance.
The transition to insulated glazing, including double, triple, and gasfilled windows, were responsible for some of the largest efficiency savings in glazing. Other energy-efficient glazing developments include reflective glass, low emissivity (Low-E), spectrally sensitive glass and tinted glass that absorbs heat. The house’s heating and cooling efficiency and monthly energy costs may be significantly improved by upgrading your windows, which account for 25– 30% of the energy used for heating and cooling a home.
The windows are getting smarter as more and more “smart” items enter in our lives. What is a smart window, and should you use one while constructing a house or replacing the windows in your existing one? These are the topics that will be addressed in this article. We’ll look at the costs, advantages, and operation of smart windows.
When discussing smart glass, you’ll often hear switchable, dimmable, or tintable glass since these variables may cause the glass to transform from transparent to translucent to entirely opaque. When compared to conventional windows, smart windows can provide significant energy efficiency improvements due to their capacity to block some or all light wavelengths. Smart glass or glazing is often used in smart windows.
The Function of Smart Windows
A unique film is laminated onto the glass to create smart glass (typically acrylic or polycarbonate laminate). You may turn ordinary windows into smart ones by purchasing “smart film.” Smart glass windows are made using a variety of technologies.
Electrochromic Low voltage electricity changes the opacity of electrochromic glass, changing how much light and heat are conveyed. Users have some choice over the pace of the transition, although the shift happens gradually. This technology might impact the durability of the glass. In museums, electrochromic glass is often used when precise control over how much light artwork or artifact is exposed is required.
Photochromic
Instead of electricity, photochromic glass responds to light, most often ultraviolet light. If you have ever worn or seen transition eyeglasses, you may be acquainted with photochromic glass. When exposed to light (such as sunlight), photochromic glass becomes darker and clearer once the light source is removed (say, when it gets cloudy).
Thermochromic
When heated, the thermochromic glass changes when the glass is subjected to temperatures above the transition temperature, which activates the thermochromic component and blocks light and heat, which results in the change in the glass’s clarity level.
Suspended-Particle (SPD)
A suspension-particle glass contains nanoparticles suspended in a liquid that responds to a lowvoltage electrical current. When electricity is provided, the particles align, making the glass transparent. When there is no transmission of electrical current, the opposite occurs, making the glass opaque.
Micro-Blinds
Electrical currents are also used by smart glasses that use microblind technology to alter the color of the glass. Micro-blinds are small metal sheets (100 micrometers in size) that curl or flatten when actuated. The blinds curl when there is no electrical current, allowing light to enter. However, the blinds flatten out to block the light when an electrical current is supplied. Micro blinds may be adjusted to the user’s choice to regulate the quantity of light that goes through, exactly like ordinary blinds.
PDLC (Polymer Dispersed Liquid Crystal)
Glass with polymer-dispersed liquid crystals is another intelligent film that responds to electricity. When no electrical current flows through the film, PDLC is similar to SPD, wherein the liquid crystal droplets are randomly placed on the film. But when triggered, the liquid crystals line up, and the film becomes transparent, letting light pass through. Due to its milky opaqueness, PDLC smart glass is often used in conference rooms, hospital ICUs, bathroom and shower doors, changing rooms, and other places where seclusion is required.
The Advantages of Smart Glass
There are just two main advantages to smart glass, despite the range of technologies utilized to create it.
Convenience
The smart window system would automatically adjust to the local temperature, thus letting the light in whenever necessary and blocking it when not.
Energy Efficiency
Windows are one of the main areas in our homes from where heat escapes and smart windows claim to increase energy efficiency by regulating the amount of light that enters the building. Some manufacturers assert that their products can reduce entry of ultraviolet light by 95% and decrease the heating and cooling costs by upto 30%.
Manufacturers could also highlight the improved privacy and security issues as important advantages. While smart windows can provide some privacy advantages, they aren’t noticeably superior to conventional windows that include blinds or other window treatments.
Smart glass system manufacturers have developed and tested intelligent glazing solutions for noise reduction, fire resistance, condensation protection, and self-cleaning.
