Types of glass for glazing facades and double-glazed windows

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Safety glass

Purpose:glazing of building facades (lower and upper floors), arrangement of internal partitions. It was used in the construction of urban facilities: Moscow City, observation deck of the Ostankino TV tower, vehicle stops. Promising areas of application for safety glass: pools and aquariums, doors and various furniture elements.


Light transmission coefficient:from 85 percent.
Features:safety glasses are mainly multi-layer structures.
Dimensions:thickness from 4 to 120 mm, cut to size.

Consumer analysis

“Safety glasses” in fact is the general name for various (by the manufacturing method, complex of components, technical characteristics and even by purpose) glass structures. They have one thing in common – they all somehow protect a person from aggressive external influences and at the same time, if anything, they themselves do not injure him with their fragments..

A special case of such glass is multilayer fire protection (those that are “from fire, smoke and heat radiation”). Undoubtedly, the well-known glass reinforced with a metal mesh is also “safe” in a certain sense. But there are safe materials that I want to talk about in more detail..

The easiest way to make safety glass is to apply a protective film, which usually consists of glue and a layer of polyester. It is glued directly to the surface of the sheet. If a stone hits such a “special glass” or an explosion thunders nearby, it will not scatter into small fragments, but, cracked, will remain in the frame. In addition, there are special protective films that turn ordinary glasses into energy-saving or fireproof.

Another type of safety glass is multilayer (laminated). In their production, a film can also be used, but “double-adhesive”, here it is located between the glass layers. The lamination process is complex, it is carried out using an automated line in several stages. The last stage is carried out in an autoclave under the influence of heat and pressure. However, instead of a film, a special laminating liquid can also work. A certain chemical composition is poured between the layers, then it is sintered with glass, forming a homogeneous body. Glass systems made using film technology are usually more expensive than “jellied” ones. Layers (straight or bent in accordance with a given shape, which is given to them before gluing) are made of glass of one or different types (simple, tempered, colored). Consumers know the name “triplex”. This is just the simplest version of a multilayer system – two sheets of plain glass, 3-4 mm each, and a 0.5 mm film between them. Triplex is used not so much as protection against hooligans, but as an element of the noise reduction system.

Armored glass is another matter. The principles of their production technology are the same, but their sheets will not only not scatter into small pieces from the fallen stone, but depending on the strength class will become an obstacle for real weapons. In the production of transparent “armor”, ordinary float glasses with a thickness of 2-8 mm and films (know-how of manufacturers) with a thickness of usually 0.5 mm are used.

For example, from an intruder armed with a TT pistol, a structure of 4 glasses, 4 mm each, will protect. This is the 1st degree of protection – the total thickness of the structure is 18-26 mm (different manufacturers indicate different numbers). Armored glass with a total thickness of about 36 mm (2nd degree of protection) will stand against the automatic fire. Obstacle for a sniper – 44 “glass” millimeters (3rd and 4th degree of protection). The most powerful multi-layer structures – 12 layers of 8 mm (total thickness 120 mm). However, the layers may not be equal in thickness – by varying the package configuration, manufacturers achieve better strength properties with a lower thickness.

Laminated fireproof glass and double-glazed windows

Purpose:installation of partitions, door and facade systems.


Light transmission coefficient:from 85 percent.
Features:laminated glass or double-glazed windows used for F-glazing protect against fire, smoke, heat radiation.
Dimensions:Pyrodur, Pyrostop – maximum dimensions 6×3.21 m, sheet thickness from 7 mm; Pyranova – maximum dimensions 1.5×2.5 m; thickness 16 mm.

Consumer analysis

In laminated glass, heat is absorbed by the intermediate silicate layer, which contains water in a crystallized state. During a fire, it evaporates and cools the glass.

Low emission glass

Purpose:glazing of windows of residential buildings and industrial facilities.


Light transmission coefficient:from 80 percent (for different manufacturers, this value fluctuates by several percent).
Features:energy saving, reflects the infrared part of the spectrum, while maintaining normal light transmission.
Dimensions:sheet thickness from 3 to 10 mm.

Consumer analysis

The problem of economical use of energy is especially acute in our time. Ordinary, so-called “raw” glass, part of the heat absorbed from the room re-radiates to the street. Losses reach 50 percent. Therefore, all the world’s largest manufacturers produce special energy-saving glass. Russian enterprises have also taken up its production, although, however, we are talking about small batches. In the future, it is planned to increase capacity so that there is enough production for all new buildings..

The surface of low-emission glass is coated with a special coating that is not visible to the eye (silver and a number of other metals are used), which allows solar heat into the room (short waves), but prevents heat radiation from the room (long waves) from leaving the room. Thanks to this, the thermal insulation of the room is significantly improved. The apartment gets warmer in winter and cooler in summer without additional electrical appliances. Ultimately, your electricity bills go down. It should be added that the coating has almost no effect on the amount of light entering the rooms. Naturally, glass “works” only in combination with modern frames.

Low-emission glasses with hard and soft coatings are produced. Hard coated glass (usually called “K-glass”, which is not entirely correct) can be used for single glazing (indoor coating) or in insulated glass units. Glass with a soft coating (you can find the name “I-glass”, which is also not entirely true) is used only in double-glazed windows, always coated inside. In terms of its heat-saving properties, a soft coating is one and a half times superior to a hard one, therefore, it is preferred all over the world..

As for the terminology, in fact “I-glass” and “K-glass” are the names of trade marks, and not the type of product (“Xerox” is also a trade mark, and not a synonym for the word “copier”). The problem is that different manufacturers have their own “brand” names for energy-saving glasses. In appearance, low-emission glass does not differ from ordinary glass. To find out if it is included in the glass unit, light a match or lighter and bring it to the window. Reflection on low-emissivity glass will differ in color from all others.

In fireproof glass units, a special transparent “liquid” gel is located between ordinary glasses. When exposed to fire, it darkens and foams, forming an opaque protective layer. Heat passes through opaque glass much more slowly. During a 30-minute contact with fire on the back of the glass, the temperature according to European standards does not exceed + 180-200 degrees Celsius. For comparison, ordinary glass during this time would have already heated up to 550. In such conditions, in a room with fireproof glass, the temperature is only 45 degrees, and with ordinary glass – up to 300 degrees Celsius. Even during a strong fire, the glass does not crumble due to the fact that the gel at a high temperature fuses with the broken glass layer close to the fire and holds it.

Fire resistant borosilicate glass

Purpose:installation of partitions, door and facade systems, roof glazing (in double-glazed windows).


Light transmission coefficient:about 90 percent.
Features:single-sheet safety glass float, retards the spread of fire and smoke (G-glazing), transmits heat radiation.
Dimensions:glass is made to order, the maximum sheet size is 160×300 cm, the minimum is 13×27 cm; thickness – 5, 6, 8 mm.

Consumer analysis

Conventional borosilicate glass is obtained by replacing alkaline components in the raw material with boron oxide. The coefficient of thermal expansion becomes low, as a result the material is able to withstand high temperatures. There is one more plus – good chemical resistance to various aggressive environments, therefore, such glass is used in the production of household appliances, heat-resistant and laboratory glassware.

By subjecting the borosilicate glass to additional heat treatment, the so-called “special fire-resistant borosilicate glass” is obtained. This material is specially designed as a fire protection and has been used in practice for 20 years. It is most often used for glazing doors installed on escape routes in hospitals, schools and nursing homes. In addition, by gluing borosilicate sheets joint to joint, continuous, without vertical profiles, glass partitions with a height of 2.2 m are made.This wall serves as a barrier to fire and smoke for 50 minutes.

In general, depending on the thickness, fireproof borosilicate glass is capable of protecting a room from fire and smoke for 30, 60 and even 120 minutes. Moreover, its light transmittance is the same as that of conventional window panes. The fact that we are dealing with fire protection can only be guessed by the manufacturer’s logos, which are applied to each side..

Borosilicate glass remains transparent even during a fire. This important feature allows victims and firefighters to navigate faster and fight fire more effectively. However, it must be borne in mind that the barrier allows not only light to pass through, but also thermal radiation, that is, heat. At the same time, fire-resistant borosilicate glass is a single-sheet safety glass. If damaged, it will crumble into small pieces with blunt edges, which will not hurt anyone. The finished glass is not subject to further processing and therefore is manufactured strictly according to ordered dimensions and finished projects. It can be used both independently and in double-glazed windows in combination with other types of special-purpose glass (heat, noise, shockproof).

Fire-resistant borosilicate glass of German production is certified in 18 countries of the world, Russia is not yet included in their number, although this glass can already be ordered in Moscow. Moreover, such glasses are already installed in some buildings built by foreign contractors..

Light and heat protection glass

Purpose:glazing of buildings, decoration of facades, office partitions, in curved (curved) and hardened form – manufacturing of trade pavilions, light-transmitting roofs, balcony railings, greenhouses.


Light transmission coefficient:from 54 to 81 percent.
Features:energy-saving float glass, colored in mass, absorbs from 27 to 70 percent of solar energy, in comparison with ordinary glass has a reduced light transmittance.
Dimensions:1.3×1.6 m; 2.0×1.6 m; 2.5×1.6 m; sheet thickness – 3, 4, 5, 6, 8, 10 mm.

Consumer analysis

Light and heat-shielding glass was invented more than twenty years ago, but it has acquired particular relevance today, when glass began to be considered as a structural material of the XXI century. During the production of light and heat-shielding glass, special additives are introduced into the raw material, due to which the sheet becomes less heat-conducting (the heat transfer coefficient corresponds to the new, toughened SNiP requirements) and transmits less light.

In rooms with glazing made of light-and-heat protective glass, temperature drops (day / night) decrease, the “blinding” effect of the sun is reduced, furniture, painted surfaces, etc. do not fade. Most importantly, heating and air conditioning costs are reduced. The industry produces light and heat protective glass in bronze, green-blue and gray colors. There are also architectural and patterned options designed to decorate the interior and exterior of buildings..

What is especially pleasant is that some brands (for example, “Metelitsa” and “Blues”) are Russian “know-how” that have no analogues in the world either in their structure or in color. However, there is some unpleasant information: there are cases when products with Russian glass (for example, doors) are passed off as Finnish or German products. Interestingly, light and heat-shielding glass can be subjected to the same types of processing as conventional.

Limitations:there are samples on the market that absorb more than 50 percent of heat. It should be borne in mind that they cannot be used for external glazing: on hot days, such glass heats up to 80-90 degrees and can burst.

Electrochromic glass

Purpose:production of partitions in offices, bureaus, offices, restaurants.


Light transmission coefficient:from 85 percent.
Features:double-glazed window, transparent when turned on and opaque matte when turned off; electrical connection (voltage – 9-12 V).
Dimensions:maximum dimensions – 1×2.8 m. Film thickness – 0.5 mm. The thickness of the glass units depends on the thickness of the glass used.

Consumer analysis

A kind of glass chameleon. Absolutely transparent, no different from the usual window, it can become dull in an instant and through it it will no longer be possible to see even the vague outlines of objects.

A double-glazed unit consists of two panes, connected with a special film (thanks to which the “color” changes) with the help of polyurethane glue. The film itself is a polymer composition containing small inclusions of liquid crystals. When installed, such glass is connected to the mains using an adapter (voltage from 9 V, energy consumption is very low). When the glass is not switched on, it is opaque, milky-white in color, as the liquid crystals are randomly arranged and scatter the incident light in all directions. But as soon as an electric charge arrives, the crystals align, the light passes through the glass without hindrance – it becomes transparent. The transition from one state to another is almost instantaneous. And you can turn it on and off as much as you like.

Theoretically, any special glass (energy-saving, triplex, etc.) can be inserted into a glass unit. But more often electrochromic sheets are used in internal glazing as an original decor, emphasizing the high material security of the owners. By the way, such glass can serve as a screen for a projector..

There are no problems with the maintenance and cleaning of the electrochromic “chameleon” – they treat it the same way as with a regular window. The only “but”: it should not be exposed to direct sunlight, as crystals react and tend to decay.

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