The need for an attractive glass exterior, which would be linked into a whole skeleton of the building and the facade is originated from the architects in the 20's. XX century. Since then, it developed many meaningful technological innovations to achieve this goal.
You can list only the main ones:
Cold front: the outer layer of the facade — glass pane. It performs the function of thermal insulation of the building wall structure on which the air gap is attached an outer layer;
Exhaust facade: outer layer — plus glazed glass, installed at a distance of 15 — 20 cm from the glass. The air gap is used or for venting and ventilation of the building or for heating the fresh air;
Structural glazing — fusion method of glass, ceramics and metal in a structure using a special silicone adhesive sealants. This type of glazing allows architects and designers to fully realize the sleek all-glass facade.
To object to the use of glazed facade and effectively functioned for a long time, need to work together architects, designers and suppliers of glass, insulating glass, profile system and silicone sealants (in the case of structural glazing).
Depending on the location and purpose of the building a key issue facade glazing is the choice of glass and construction glass. Making the right choice, you can avoid heat loss, greatly reduce the penetration of noise from the street, to ensure safety standards to protect the interior of the excess solar energy. Assortment « special » Today glass is extremely wide, and to navigate in this variety of types and brands of different manufacturers, without the help of professionals can not do.
Consider the basic functions of glass and some practical advice on their implementation.
insulation
Keep in mind that one-third of heat loss through the glass is carried out by conduction and convection, and two-thirds — by thermal radiation with a wavelength. The problem of convection and thermal insulation is achieved through the installation of double-glazed windows, and optimally, if the thickness of the air layer between the panes of glass is less than 16 mm — otherwise increases convection and insulating characteristics deteriorate.
To reduce losses from heat radiation developed the so-called selective (low emissivity) glass with a special coating. Currently, there are two types of such glasses: « K-glass » — to « solid » coated « i-window » — to « soft » coating. « I-Glass », appeared later, has thermal insulation characteristics is 1.5 times higher than the « K-glass », so the market share of « i-window » growing, they are glazed majority of projects under construction in Europe. Because of « soft », t. E. Exposed to the external environment covering, « i-window » It used exclusively for insulating glass, and is set by the space inside the glass coating. The need for high-tech working with « i-glass » It led to the fact that double-glazed windows with glass produce only large specialized firms.
Sun protection
Under the solar glass is meant glass, having the ability to reduce the penetration of solar thermal and/or light energy in the room by absorbing or the reflection of the sun rays. They have this property of glass, tinted in mass, and reflective (reflective) glass mirror-coated kind. This is the most extensive and varied in appearance a group of glasses, because especially loved by architects and the most frequently used in the facade glazing.
As an example, a list of brands of sun glasses, produced by the International Corporation Glass « San Gobain ».
« Parsol » — tinted heat-absorbing float glass of different colors (bronze, gray, green, pink). Each tone of glass correspond to different spectrophotometric characteristics (transmittance, reflectance, absorption of solar energy). The use of tinted glass with a transmittance of less than 50% as the facade is not recommended due to increased risk of thermal shock (glass breakage due to overheating and temperature drop), although it is possible its use in the hardened form after special calculations.
« Antel » — reflective glass « solid » (resistant to the external environment) coated with metal oxides (reflectance of 29 — 32%). As a source is used as a colorless and tinted glass that produces a color « Antel » — bronze, emerald, silver, and others.
« Reflektasol » — silnozerkalnoe glass (reflectance of about 50%), providing almost one-sided observation. If necessary, the mirror effect can be reduced by 10 — 12% by setting the « Reflektasola » in coated glazed inside. Coverage « Reflektasola » It refers to « solid » and may have different shades of color.
Tinted and reflective glass « solid » coating can be used for single glazing (« cold front »), and the double glazing.
« Cool-Light » — solntseotrazhayuschee glass « soft » coating. A method of manufacture in which the original colorless or tinted glass is applied several layers of different metals, allows you to get about 65 species of « Kul-light » wide variety of colors (blue, blue, steel, gray, bronze, etc.) and with different properties (light transmission from 4 to 50%, the reflection from 6 to 43%).
« Cool-Lite K » — the glass of the new generation that combines the two functions at the same time — reflectivity and energy savings. « Soft » This glass coating is selective, providing excellent thermal insulation, and at the same time a mirror of different colors (as in glass « Cool-Light »). In developed countries, it is « Cool-Lite K » most often used for facade glazing, t. To. It gives architects a lot of room for creativity, while allowing the necessary provisions to ensure energy saving and shading. As with any glass « soft » coated, « Cool-Light » and « Cool-Lite K » It applies only in glass.
At the St. Petersburg market reflective and low-E glass are not only the trademarks of leading foreign manufacturers, such as « San Gobain » (representative of the market of St. Petersburg — Company « AKMA »), « Glaverbel » (Representative — Company « Borskoye Glass »), and the domestic manufacturer — Company « architectural glass plant », which since the beginning of 2000 started production of low-emission and solar control glass to « soft » US coating equipment.
Desk
called isolation from noise attenuation of sound energy as it passes through an obstacle (glazing). Soundproof glazing is dependent on:
- the number, size and thickness of the glass in the pane;
- the thickness of the air gap between the panes;
- permeability joints.
Increasing the amount of glass in the pane does not always lead to the desired result. If you simply install the glass in the middle of the air gap, the sound insulation is reduced due to the increase of the resonant frequency of the structure. With triple glazing (double-glass) with an acoustic point of view, more appropriate to apply an increase in the thickness of the glass and the air gap between them, and the camera glass need not be symmetrical. A further improvement is achieved by pumping gas into the space between glass panes. A more radical solution to the problem — the use of glass as part of special laminated glass with noise-reducing films.
Usually, sound conventional single-chamber glass 4-16-4 (two panes of 4 mm thick air gap — 16 mm) up to 28 dB, double chamber 4-10-4-10-4 — 32 dB, a special laminated glass — 50 dB. Keep in mind that the threshold of hearing for a man — 0 dB; increase in the sound pressure level of 10 dB is perceived by man as doubling the volume.
Security
safety glazing differ in protection class:
- Class of « A » — glazing, withstanding the occasional blow;
- Class of « B » — glazing, resistant to cracking, vandalism;
- Class of « In » — bullet-proof safety glass.
To ensure the safety glazing use: tempered glass, wired glass and laminated glass.
Wired — this glass with a metal grid inside; when broken shards of glass such does not fall even when the formation of some cracks, and held in place by the reinforcement.
Tempered — glass, which by heat or chemical processing increases resistance to shock and temperature changes in the 5 — 10 times compared with a conventional glass. With the destruction of the glass breaks into small safe splinters blunt. It should be noted that not all types of glass can be tempered, for example, glass « soft » coating undergoes hardening, usually prior to coating.
In St. Petersburg, hardened glass can be carried out in the company « Borskoye Glass », using equipment « Tamglass ».
laminated glass (triplex) consists of two or more sheets of glass of different types and thickness, laminated (bonded) with the help of special polyvinyl film or laminating the liquid. When broken behaves like reinforced glass. By varying the glass and the film can be obtained triplex combines security property to other properties of thermal insulation, sound insulation, fire protection and so forth. The lack of laminated — large glass thickness, ie big load on the edge compound glass, also reduced light transmission as well.
In St. Petersburg, laminated glass produced by many companies, but unfortunately, only using the « filler » technology that does not provide a high quality laminated glass. « Film ».
Aesthetic
The harmonious combination of color, transparency and degree of reflection glass facade with the environment, of course, very important. Please note that the error in the performance of glazing can lead to a defect of the facade as a « waviness » (glass surface is similar to the « distorting mirror »). To avoid « waviness » Glass facade must be used outside the glass thickness of at least 6 — 8 mm depending on the size of the glass panels. You should also take into account the specifics of the climate (large temperature difference during the year) in the manufacture of insulating glass. The temperature and pressure in the space between glass panes of glass made in the summer, will be very different from the conditions of its operation in the winter. The low temperature reduces the pressure inside the glass, because of what glass can bend inside the glass, breaking glass, and ensuring equality of « waviness » facade.
To avoid such troubles, glazing must be ordered only professional manufacturer of insulating glass, working on modern equipment and use cutting-edge technology.
In the case of a continuous glass facade glass solntseotrazhayuschim question — How to ensure a single mirror effect without the « banding », sometimes arise due to location just behind the glass facade of opaque intermediate floors, alternating with the window openings of the building. This problem is solved by a special glass facade , obtained by applying an opaque colored enamel coating on the reverse side solntseotrazhayuschego glass used in the glazing. This type of glass is made only by foreign glass company.
From the foregoing, it is clear that a variety of options facade glazing is almost unlimited. To facilitate decision-making on Selecting glazing the world's leading glass manufacturers have developed special computer programs, where the given embodiment of the glazing (single, double pane windows, sloping glass roof, etc.), the thickness and the type of glass used, the width of the air gap, the orientation of the facade parts of the world, climatic data etc., on the basis of which the program calculates all necessary thermal characteristics of glass, the risk of thermal shock, as well as the maximum permissible wind and snow loads for the design.
|