Smart technology is letting the sunshine in. And keeping it there.

Although much of the technology is still under development, the smart window is another IoT technology with the potential to change the way we live.

According to the U.S Department of Energy, older, inefficient windows can be responsible for more than 25 percent of the energy costs from heating/cooling a home. Smart window tech can save up to 20 percent in heating and cooling costs, according to Stanford researcher Michael McGehee.

Smart windows can also regulate light, potentially saving the homeowner the cost of drapes, curtains and blinds. Other benefits include automated control over windows from remote locations and improved overall home security.

But replacing windows is costly. Add smart window tech into the bargain and homeowners are looking at a hefty price tag. Still, it’s a technology with a lot of promise, and costs are sure to come down as use becomes more widespread. And some exciting developments are underway.

Types of smart windows

Using different methods, smart windows regulate the light and heat transference that enters a room through the window glass. Types of windows include:

Electrochromic—Through a combination of electrolyte gel and a transparent conductor, electrochromic windows tint on demand. Present models take up to seven minutes to transition and don’t get dark enough for wide-spread residential use, but researchers are working on a prototype that changes opacity in three minutes. An electrical charge is required.

Low-emissivity (low-E)—Glass using a thermochromic filter combined with a microscopic layer of metallic particles reflects infrared radiation from the outside or inside of the home. So, in the summer solar energy is reflected back, cooling the home; in the winter, the coating reflects infrared radiation from within to keep the home warmer. This layer also protects fabrics from fading by blocking UV rays. With no wires or electricity required, these windows work upon installation in new construction or retrofitting for existing windows.

Smart film—A film of PDLC (Particle Displaced Liquid Crystal) can be retrofitted onto any window. When a voltage is applied, the film becomes clear; when the voltage is removed, the film becomes opaque.

Concerns for integrator or installers

To ensure homeowners can operate their smart windows, mesh networks are better at providing full coverage throughout a building. (Read our post comparing wireless switches and smart home hubs to learn why.) This is critical for smart windows to be controlled effectively. The leading standards are Z-Wave and Zigbee, but which one is best for the newest smart window tech remains to be seen.

As Residential Tech Today writes, “Every time a consumer wants to upgrade their smart home, they need to research whether the peripheral they want to install is compatible with their smart home processor/hub.”

Also, using a Wi-Fi transparent engineered plastic media panel will help integrators manage the transition to broadband and smart home installations with greater flexibility and adaptability.

Emerging window technologies

As mentioned, the technology is still in its development stage. There are several new and coming developments, including:

Window sensors and locks
The sensors connect to your home and communicate information about your windows to an app. This allows homeowners to check their windows from an app. With smart window locks, they can open and close the windows. (The sensors and locks can also be applied to doors.)

Solar windows
Researchers at Michigan State University are developing what they call a “transparent luminescent solar concentrator.” The concentrator uses organic molecules to absorb ultraviolent and near-infrared wavelengths. Potential applications include use in high-rise buildings, residential new construction and replacement windows, smartphones, and cars.

Self-cleaning glass
Sunlight combines with a coating of titanium dioxide to break down organic compounds that have stuck to the glass. The second part of the coating allows water to easily rinse dirt like bird poop off the windows.

HD screens embedded in glass
Though mostly used in business, HD screens embedded in windows is an option for homeowners. Cost and availability are factors for consideration.