When used to cover the exteriors of buildings, glass imparts a sleek and clean visual character that has remained popular in twentieth-century design. Glass is a versatile and attractive construction material. A designer can incorporate as much design direction to anything and become inventive with the material. However, glass does have some drawbacks. The glass easily allows solar radiation transfer, demanding air conditioning to maintain suitable indoor temperatures. Solar glare can cause visual discomfort if there is too much daylight. Designers often consider sun-shading devices such as curtains, shades, louvers, and fins to address the issue. Sun-shading devices are architectural compensations used to mitigate transparency, adverse effects of a double-edged sword. Recent glazing technology and electrochromism have developed adaptive tinting capabilities that offer creative solutions. Electrochromic glass is a type of smart window glass. It can change its opacity by using electricity to either block or allow the passage of light.
Eliminating Curtains With Electrochromic Glass
Electrochromic glass (EC glass) is a smart glass that can also be colored electronically. The application is highly appealing for windows, skylights, and facades. Electrochromic glass dims automatically in response to the amount of daylight, making it a very intuitive sort of glazing. Additionally, building inhabitants can set it manually via a switch or mobile application. Electrochromic glass is an excellent choice for buildings that face a lack of natural light, such as classrooms, hospitals, office spaces, shopping areas, displays, and art galleries. EC glass is also an excellent choice for interior areas with atriums or skylights. It essentially eliminates the need for blinds or curtains because the glass can block approximately 98 percent of light at full tint or darken to the desired level in response to exterior light conditions. This feature is advantageous for controlling the room’s ambiance, temperature, and privacy while reducing a building’s energy consumption for air conditioning.
A Switch Away From Privacy
Since many modern office buildings are nearly totally partitioned by glass panels, electrochromic smart glass is ideal for corporate settings. With many people working throughout the day and frequently into the evening, businesses may save significant money in the long term by managing interior light and temperature autonomously rather than relying on air conditioning or artificial lighting. Interior electrochromic glass partitions can provide privacy in meeting rooms, conference rooms, function halls, and offices at the flick of a switch. Smart glass’s fundamental, albeit obvious, advantage is that it eliminates the need for temporary separation via draperies, blinds, curtains, or improvised partitions. With the popularity of open floor plans for flexible work environments, EC glass is the ideal component for separating public and private spaces.
Electrochromism?
Standard windows consist of a single vertical pane of glass, but double-glazed windows contain two panes of glass segregated by an air gap to improve heat insulation and soundproofing. Advanced windows, such as Low-E glass, are coated with a thin layer of metallic compounds to regulate the inside temperature depending on the season. Electrochromic windows operate similarly to conventional windows. The glass material comprises metal-oxide layers similar to the manufacture of integrated circuits.
Electrochromism is the process of using electricity to alter the color or tint of anything. An electrochromic coating made from Tungsten oxide blankets the PET (Polyethylene terephthalate) foil. Two PVB or SGP laminate films and two glass panes protect the foil from either side. Electrode strips at the glass panes’ periphery carry electricity from a very flexible double-insulated wire to the coating. The electrochromic and electrolytic layers are at the structure’s core. When a low voltage passes through the coating, lithium ions activate the electrochromic layer of tungsten oxide, which is transparent when not in use, altering the opacity of the glass. Electrochemical reduction-oxidation is the process that results in light absorption and coloring. The lithium ions migrate back into the electrolyte when the voltage is reversed, restoring the glass to its original transparent state. This procedure is a lengthy process that may take several minutes. Electricity is not required to sustain opacity levels; instead, it is necessary to transition between light and dark states. Electrochromic glass runs at low voltages than 150 square meters of smart glass consumes the same level of energy as a 60 watt light bulb. In other words, each square meter of glass will not alter the hue beyond 7 watts.
This breakthrough results from over three decades of pioneering electrochromic coating research with local institutions and experience combining electric components with glass. Electrochromic coatings are advantageous for single-, double-, triple-, and even quadruple-glazed windows. Single-glazed EC glass is approximately 21mm thick, double-glazed EC glass is about 43mm thick, and triple-glazed EC glass is approximately 65mm thick. Smart glass has an average lifespan of around 30 to 50 years or approximately 7 million hue variations.
Electrochromic Glass with a Hybrid Composition
Hybrid EC glass is memory-based and can retain its state for four to five days. It consists of an inorganic electrochromic film sandwiched between two polymer electrolytes. However, leakage reduces charge retention, gradually reverting the EC glass to its clear state. This hybrid glass is feasible only for internal glass setups.
Electrochromic Solid-state Glass
While solid-state EC glass lacks this memory property, it demonstrates exceptional resilience in cyclic tests at severe temperatures and UV radiation, resulting in a lifespan of around two to three decades. Due to its increased durability, it is perfect for building facades.
Integrations in the Future
Another possibility is to combine smart glass and photovoltaic cells so that, rather than reflecting sunlight, darkened EC glass can capture and store it. On paper, having photovoltaic windows that capture solar energy that falls on them during the day and store it in batteries to provide illumination at night may sound ideal. However, a window cannot be wholly transparent and operate as a 100 percent efficient solar panel at the same time. The glass either transfers or absorbs the incoming energy, but not both. A window that doubles as a solar cell very probably requires compromise on both sides: it would be a relatively dark window even when clear, and it would be far less efficient at collecting energy.
Additional Uses Of Electrochromic Glass
Other inventive uses for smart switchable privacy glass, intelligent switchable film, and electrochromic glass technology include the following:
- Blinds/curtains that operate electronically
- Control of daylight
- Partitions for security
- Automobile windows
- Atriums and skylights
- Cases de exposition
- Façade with single/dual glazing
- Bank/ATM entrances
- Partitions for bathrooms, showers, and toilets
- Intelligent Windows
Glass industry advancements give architects greater creative license to design interior and external spaces and create new concepts by controlling daylighting. Additionally, electrochromic glass provides new ways for tenants to interact with smart living and intuitive technology in a built environment. The widespread adoption of electrochromic glasses in future residential and commercial settings gives us a glimpse into the future adaptive building facades or, more specifically, the modern applications of glass envelopes.
