Modular transparency, active control of light and heat, ability to adapt to environmental conditions: the so -called “intelligent glasses”, or Smart Glassrepresent one of the most advanced borders of innovation in construction, capable of combining aesthetic, comfort and sustainability.
What is meant by “intelligent glass”
With the term Smart Glass Reference is made to glass equipped with active features, that is, capable of changing their physical or optical properties in a controlled way (such as transparency, color, heat transmission and light), in response to external stimuli:
- optical (light),
- thermal (temperature),
- electric (current application or voltage).
This makes glass an active element of the building envelope, capable of dynamicly contribute to environmental comfort, energy saving and quality of life in the spaces built. Let’s see what are the main types of smart glass.
1. Cromogenic glasses: the family of the glass that change
Chromogenic glasses modify their state of transparency according to light, heat or electrical impulses. Are divided into:
- Photocromic: they change the degree of darkening based on the accident light. Used mainly in the automotive and glasses sectors, but not very applied in construction for long response times and the difficulty in precise control of the dark.
- Thermochromic: they react to the external temperature (e.g. threshold of 30 ° C), becoming opaque or dark. They are employed in passive projects, but are affected by a poor repetability of performance and do not allow manual control.
- Gasromic: still experimental technology, based on chemical reactions activated by injected gases. Very expensive, not adjustable, and not suitable for common building applications.
- Electrocromic: they are the most promising solution: they activate through electrical impulses, which determine the migration of metal ions within nanometric layers. They allow precise and gradual control of the dark, manual or automatic.
The latter technology is used in dynamic facade glass, especially in high efficiency buildings or with strong sun exposure.
2. Heating glasses: comfort and anti-condensation
Heating glass, or Heated Glassemit heat thanks to the application of electric current. Are distinguished according to the system:
- with serigrafati conductive threads (visible or not),
- With transparent conductive coating, typical of the BE (bass emissive) glasses treated pyrolically.
Are used for:
- eliminate condensation (in bathrooms, saunas, refrigerated windows),
- heat internal environments, replacing radiators,
- Eliminate the cold wall effect, typical of large glass surfaces.
The most common configuration provides that it is the inner plate of the window to warm up, but there are also solutions on external slab or on both, in stratified windows.
3. Led crystal glass and LED glass
This technology (LCD Glass) exploits liquid crystal films (PDLC – Polymer Desverged Liquid Crystals) inserted between two stratified slabs. When the current is active, the crystals align and the glass becomes transparent; When the current is off, the glass returns opaque.
The main advantages:
- instantaneous switch on/off,
- Dynamic privacy (ideal for internal walls, meeting rooms, hotels, bathrooms),
- Possibility to use glass as a projector screen.
An evolution of liquid crystals are the glasses with LED integration, capable of viewing texts, numbers or images. Used for interactive showcases, digital signs or architectural design totems. They mainly have retail, museum and exhibition applications.
4. Self -cleaning glass and antibacterial glass
The self -cleaning windows, covered with coating based on titanium dioxide (tio₂), exploit two mechanisms:
- Photocatalysis: UV light decomposes organic substances;
- Hydrophilia: the water slips evenly on the surface, removing dirt.
It is a useful solution for inaccessible facades, skimmer, shelters, with advantages in terms of maintenance and aesthetic performance over time.
Some special coats also allow the glass to have real permanent antibacterial properties, useful for hospitals, workshops, canteens and controlled contamination environments.
5. Anti-Fog glass: against fogging
Anti-suppliament glass (anti-child) are ideal for environments with high humidity. Two mechanisms:
- use of anti-condensation coating (for molecular attraction),
- or integration with self -cleaning windows, which strengthen its effect.
6. Photovoltaic glass and glass that produce energy
These are glasses capable of generating electricity, through:
- integrated photovoltaic cells (e.g. to amorphous silicon),
- Semitransparent glass, usable as active facade elements (bipv).
They allow to produce energy from transparent surfaces, also in buildings for tertiary use, schools, greenhouses, canopies, canopies. They are part of the logic of Nzeb (Nearly Zero Energy Building).
Glass becomes a technology
Smart glasses are no longer a curiosity for iconic architectures, but concrete technical tools to improve energy efficiency, visual and thermal comfort, the dynamic management of light, the safety and health of the environments.
Designers, windows and companies must therefore learn to know these new technologies better and correctly evaluate the services declared, also considering aspects such as durability, electrical compatibility, safety and reference regulations.
