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Smart Glass Explained

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More and more Australian offices and homes are turning to smart glass as the perfect solution for providing both privacy and thermal control. Smart glass becomes darker when it is exposed to sunlight, thereby reducing the amount of heat energy that enters the building. Not only can this reduce air conditioning costs, but also it means that you can see clearly out the window at all times, even in the heat of the day, when bright sunlight can be a nuisance. As the sun lowers in the sky, smart glass allows more light to flood in, meaning that electrical lighting costs are also minimised. Overall, chromatic glazing has many advantages over traditional glazed windows, but how does it work?

Electrochromic glass, as smart glazing is referred to in the industry, is a submembrane of a window fitting that can be made of either plastic or glass. The tinting membrane is made up of several fine layers put together by a process of sputtering. When fully made, there are five ultra-thin membranes on the inside of the window's pane. There is a separating layer in the middle of these five layers with two electrode layers on either side of the layer. Outside of the layers are twin transparent electrical contact membranes. When no electrical power is supplied to the electrode layers, the glazing is clear. Window tinting is achieved when the electrode layers are charged. When powered up, lithium ions in the electrode layers move from one electrode to the other. As more of these ions reach the outer-facing electrode layer, the window gets more tinted, and more of the sun's rays are reflected away.

One common misconception concerning smart glass is that it requires constant electrical energy to keep the sun out. This is not so. Yes, a charge is required to get the ions moving through the separating membrane initially, but the energy of the sun is all that is needed to keep the window functioning fully. As the sun goes down, the energy level drops and more lithium ions migrate back to their original position, allowing more light in. Therefore, very little energy is required to keep an entire installation of smart glass running. The system can be entirely automated if a photo-sensor trips a circuit to engage the initial power burst when the sun comes out. When you consider the energy savings these glazing units can bring to a building, the amount of electricity they consume in operation is minimal.

For more information, contact a window installation professional.