Written by Morgan Kaenzig de Denus, AMAST Content
While most glass is static, smart glass allows glass to become multifunctional. Smart glass, also called light control glass (LCG), privacy glass, switchable glass, dynamic glass, or smart-tint glass, can appear opaque, translucent, or transparent. As a result, buildings that use smart glass can effectively balance the occupants’ desires for natural light, views, an open floor plan, energy conservation, and privacy.
What Are the Different Types of Smart Glass?
There are two main types of smart glass: active smart glass and passive smart glass. Active smart glass requires an electrical charge to change the glass’s opacity, while passive smart glass does not need an electrical charge to change its opacity.
Active smart glasses use transformers or controllers to change the glass’s state. Transformers must be turned off for part of the day and can only change glass from clear to opaque. However, controllers can use dimmers to change the voltage gradually, allowing for users to control light. Controllers are also able to maintain a continuous charge.
Polymer Dispersed Liquid Crystal
This form of active smart glass consists of a film interlayer that is laminated or retrofitted onto glass. Polymer Dispersed Liquid Crystal films (or PDLC films) contain liquid crystals that are dispersed into a polymer. When electricity is introduced, the molecules within the film are polarized, or lined up, allowing light to pass through the film. If there is not any electricity, the molecules or particles will be randomly scattered, making the glass opaque.
Suspended Particle Devices
Suspended Particle Devices (SPD) contain tiny solid particles that are suspended in a liquid. They are coated between thin layers of PET-ITO, creating a thin film.
SPDs can be dimmed but will not turn completely opaque, so they are not ideal for privacy purposes. However, they are very fast-acting and can block up to 99% of incoming light just seconds after shifting the voltage.
Electrochromic glass will slowly tint a window to filter heat and light from solar rays, though it cannot turn completely opaque. Ionized particles are driven by two electrodes to the inside of the glass or the outside of the glass, which results in transparency or opacity, respectively. Once the particles have moved to their new position, they will stay there, even without a current.
Thermochromic glass changes in translucency when heat is applied. When the external temperature is higher than the transition temperature, the thermochromic filter on the glass will activate. Within minutes, a tint will appear in the window which will block heat, light, and glare. While blocking these elements, thermochromic glass will still allow people to have clear views.
Laminated PDLC or SPD glass is ideal for new construction projects or renovation projects where the glass is being replaced. Laminated glass is very durable and can withstand high-volume use, humidity, excessive cleaning, and more.
It generally takes four weeks for laminated PDLC or SPD glass to be produced. A glass fabricator will cut a sheet of PDLC or SPD film and then carefully seal it between two glass panes. Then a professional will install the glass and an electrician will connect it to a power source.
Some films can be applied to existing windows. This is a good choice for when the glass cannot be replaced or it needs to be thinner than a double pane. The films can be applied by a professional with wet or dry adhesive. A wet adhesive is easier to adjust, but a dry adhesive will work just as well.
What Are the Benefits of Using Smart Glass?
Versatility and Convenience
Smart glass is dynamic. It can change states to fit the inhabitants’ needs and can completely transform the room when it becomes opaque or transparent. Some forms of smart glass can even be used as a projection screen.
With smart glass installed, inhabitants can quickly and conveniently adjust how much natural light and privacy they need. Buttons, switches, and even voice commands can change the smart glass’s state, so there is no need to struggle with curtains or blinds.
Smart glass offers privacy while also meeting the building’s need for light. Often, total privacy means darkness and artificial lighting, but with smart glass inhabitants can experience total privacy without completely blocking out the sun’s natural light. Smart glass is also more convenient to flip a switch than to pull the blinds or shades.
Smart glass can also block harmful UV rays while still allowing plenty of natural light into the space. It is estimated that smart glass can block up to 95% of the sun’s UV rays. In comparison, 55% of UV rays pass through float glass.
Smart glass can help reduce the amount of light and heat passing through the window, which will reduce the building’s solar heat gain. As a result, the building will be more energy efficient.
Many are discouraged from installing smart glass windows on their projects due to the more expensive up-front cost of smart glass. However, smart glass has the potential to save building owners 20% of energy costs, resulting in an excellent return on investment. People can recoup the cost difference between smart glass windows and conventional glass windows in just a few years.
What’s Next for Smart Glass?
Active smart glass technology only began in the early 2000s, but it is already taking off and will likely become even more popular in the coming years. The rise of smart glass will allow more people to balance their natural light needs with their privacy needs while also becoming more energy efficient.
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