Switchable privacy and dynamic tinting glazing
Smart glass changes its optical state on demand rather than being fixed at manufacture. Two distinct technologies get grouped under the name, and they solve different problems — confusing them leads to the wrong product being specified.
Switchable privacy glass goes from clear to opaque, instantly, for privacy. Electrochromic glass goes from clear to tinted while staying transparent, for solar and glare control. One is an interior privacy product; the other is an exterior energy product.
Both are laminated assemblies, so they can be combined with safety and acoustic performance and built into insulated units for thermal performance.
Worth settling before anything else, because the specification decision follows from it.
| PDLC (switchable privacy) | Electrochromic (dynamic tint) | |
|---|---|---|
| What changes | Clear to opaque | Clear to tinted — stays transparent |
| Switching speed | Effectively instant | Gradual — minutes |
| Purpose | Privacy on demand | Solar and glare control |
| Unpowered state | Opaque | Holds its state without continuous power |
| Typical use | Meeting rooms, medical, interior partitions | Exterior facades, skylights, west elevations |
PDLC — switchable privacy. A polymer dispersed liquid crystal film is laminated between two panes. Unpowered, the crystals scatter light randomly and the panel is opaque. Apply a low voltage and they align, and the glass turns clear. The change is effectively instantaneous, which is what makes it useful — a meeting room becomes private the moment someone flicks a switch.
It controls visibility, not heat. An opaque PDLC panel still admits a great deal of light and solar energy. It is not a solar control product and should not be specified as one.
Electrochromic — dynamic tinting. An electrical charge drives ions through a coating stack, darkening the glass to a tint while keeping it transparent. You can still see through it. Switching is gradual, typically minutes rather than seconds.
This is a genuine solar control product. It manages heat gain and glare across the day without blinds, which is why it appears on west elevations and skylights where fixed glazing has to compromise between the worst-case sun and the rest of the time.
PDLC suits interiors. Conference and boardroom partitions, medical and consulting rooms where privacy is needed intermittently, ICU and treatment room doors, and residential applications — bathroom glazing, or a partition between rooms that should sometimes be open and sometimes not.
Its advantage over blinds is that there is nothing physical to operate, clean, damage or replace, and nothing collecting dust in a clinical environment. In a hospital or a lab that is often the deciding argument rather than the aesthetics.
Electrochromic suits exteriors. West and south-facing facades that overheat, skylights and overhead glazing where shading is difficult to retrofit, and buildings where the design will not accommodate blinds or external shading.
It competes against a fixed Low-E coating plus shading, and the argument is that a fixed coating is a permanent compromise — dark enough for August means dark in January too. Dynamic tinting adjusts.
Smart glass is glazing with an electrical requirement attached, and that is where projects run into trouble late.
Power to every panel. Each unit needs a supply, and the cabling has to be routed through or alongside the frame. This is a coordination item between glazier and electrician, and it has to be settled at design stage — retrofitting a power route into an installed frame is difficult and usually visible.
Control strategy. Wall switch, remote, app, occupancy sensor, timer, or integration with a building management system. Simple is usually better, but the decision affects the wiring.
The unpowered state. PDLC defaults to opaque with no power. In most cases that is the safer failure mode — a power cut leaves a meeting room private rather than exposed. But it is not always what a room wants, and it is worth confirming against how the space is used.
Appearance when switched. PDLC in its opaque state has a translucent white appearance rather than being a solid panel. It obscures the view without blocking light. Clients who expect something like a wall are sometimes surprised, so a sample is worth arranging before committing on a large installation.
Because both technologies are laminated assemblies, they carry the properties of a laminate. Fragments stay bonded to the interlayer if the glass breaks, and the assembly provides useful acoustic damping.
Panels can also be built into a sealed unit, so an electrochromic outer pane can sit in front of an argon-filled cavity with a Low-E coating handling the rest of the thermal work.
Where a rated opening is involved, note that smart glass and fire-rated assemblies are separate specifications — a switchable panel is not fire-rated unless it is part of a tested rated assembly.
Smart glass is one of the products where the specification decision and the coordination decision are the same decision. Power routing, control system, panel zoning and the frame detail all interact.
Tell us the room, what problem you are solving — privacy or heat — and how you want it controlled, and we will tell you which technology fits and what the installation actually requires.
This page will be expanded with fuller detail and product specifics. In the meantime call 929-235-1233 or send us the details.
Laminated Glass Low-E Glass Tinted Glass Insulated Glass Units Panels & Partitions Glass Specifications
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