Connecting Smart Glass to Electricity
- SFI Team
- 2 days ago
- 5 min read
Introduction
Smart glass using PDLC technology offers on-demand privacy through a simple electrical activation: transparent when powered, opaque when not. However, for this technology to work effectively and safely, a proper electrical connection is essential.
In this article, we will explore the core components—controller, transformer, wiring, wall switches, and remotes—as well as practical installation guidelines and safety standards. The focus will include specific use cases such as bathrooms and hotel environments, where flexibility and privacy are key.
Why Smart Glass Requires Electricity
PDLC-based smart glass (Polymer Dispersed Liquid Crystal) changes its transparency status depending on the presence or absence of voltage. When voltage is applied, the liquid crystal molecules align and allow light to pass through, making the glass transparent. Without voltage, the molecules scatter, and the glass becomes opaque.
This unique functionality offers tremendous advantages in areas requiring variable privacy—such as hotel bathrooms, medical clinics, meeting rooms, and residential spaces. For example, in several European hotel chains, PDLC panels have been installed between bedrooms and bathrooms, allowing guests to choose whether to expose or obscure the space at the touch of a button.
Importantly, smart glass defaults to opaque mode during a power outage, ensuring privacy is always preserved when electricity is unavailable.
Controller, Transformer & Safe Voltage.
The core of any smart glass system is its controller, which transforms standard 110/220V AC household current into 48V AC—a low, safe voltage specifically suited for PDLC film operation. This voltage is not only technically required but also significantly reduces risk in wet or exposed environments.
Unlike DC, which would degrade the liquid crystal over time, AC is essential because it continuously alternates polarity, helping preserve the lifespan and clarity of the film.
The controller also includes an integrated RF receiver, which allows remote operation without additional components. The system supports control through a radio-frequency (RF) remote (315MHz), which can work in parallel with a wall switch or smart home system, offering maximum flexibility. Multiple remotes can be paired with the same controller.
For safety, the controller contains an internal fuse, which protects against short circuits or overload. In the event of failure, the fuse can be easily replaced.
The controller must be certified—either with the European CE or USA UL. Certification ensures compliance with electrical safety regulations, electromagnetic interference limitations, and product reliability.
When installing the controller above a suspended ceiling, it is essential to include a technician access panel, allowing maintenance, fuse replacement, or inspection.
Wiring & Connection: Smart Film vs Smart Glass
There is a fundamental difference between wiring smart film and laminated smart glass:
Smart Film. The power connection is via exposed wiring attached to the top edge of the film. Since the film is applied to an existing glass surface, the wiring typically needs to “climb” up the wall toward the ceiling or controller. To maintain aesthetics and protect the wiring, it’s common to cover it with an aluminum or plastic profile.
Smart Glass. The wires are embedded between the glass layers and exit from the edge. A hole must be drilled into the top aluminum profile, and the wiring is then passed through this hole into the space above the ceiling. This creates a clean, seamless look with no visible external wires.
In both cases, proper installation practices are critical: use neutral silicone sealant, ensure secure insulation, and avoid sharp bends or strain on the wiring.
Switches, Remotes & Smart Control.
One of the biggest advantages of smart glass is flexible control options:
Dry-contact wall switch (no live phase): This type of switch sends a low-voltage signal to the controller without carrying high voltage itself. This allows safe installation even inside a bathroom, near wet areas.
RF remote control: The included receiver in the controller supports wireless remotes that function concurrently with the wall switch. This dual-mode control is particularly useful in spaces where multiple users or locations require access.
Smart home integration: The controller can be connected to home automation systems (e.g., Shelly, Fibaro, KNX) using a dry contact or relay output. This allows for automated operation via apps, timers, voice assistants, or motion sensors.
This multilayered control system enables users to adapt smart glass functionality to their lifestyle or work environment, whether it’s a private residence, office, or hotel.
Installation Considerations & Controller Placement
Proper controller placement is essential for both performance and safety. Most commonly, the controller is installed above a suspended ceiling to conceal wiring and maintain a clean interior design.
However, this setup must include a technician access hatch—an opening that allows maintenance access to the controller, particularly for replacing the fuse or checking connections.
If a suspended ceiling is not available, the controller can also be installed inside a dedicated electrical cabinet or technical wall niche, as long as it is dry, ventilated, and accessible.
Contrary to some misconceptions, smart glass does not save energy. While power consumption is low (typically under 0.5 watts per square meter when transparent), its purpose is privacy, not thermal insulation or energy efficiency.
Conclusion
Connecting smart glass to electricity requires thoughtful planning and professional execution. Using a certified controller, safe 48V AC voltage, clean wiring, and flexible control options—including wall switches, remotes, and smart home systems—ensures reliable performance. Proper placement of the controller, along with an accessible service hatch, guarantees ease of maintenance and long-term durability.
Questions & Answers
Does the controller need certification?
Yes. It must have CE or SII certification to comply with safety and performance standards.
What is the fuse in the controller for?
It protects the system from short circuits and can be replaced if blown.
Can I use both a wall switch and a remote control?
Yes. The controller supports simultaneous use of both.
How many remotes can be connected to one controller?
Multiple remotes can be paired as long as they match the RF frequency.
Can the controller be hidden inside the ceiling?
Yes, but only if there is a technician access panel for future maintenance.
What’s the difference in wiring between smart film and smart glass?
Film wiring is external and often covered with a profile. Glass wiring runs internally and exits through a drilled hole in the frame.
Why 48V AC and not DC?
AC allows periodic polarity changes necessary for PDLC stability and lifespan.
Does smart glass save energy?
No. It provides privacy but is not intended for thermal insulation.
Can it work with home automation?
Yes. A dry-contact output enables integration with smart home systems.
What should I do if the controller stops working?
Open the access panel, check and replace the fuse if necessary, or consult a technician.
