Twenty-first century glass is no longer just a frame filling which lets natural light flow into the room now it offers other additional features. It allows energy savings and a significant reduction in household energy consumption, which means smaller utility bills. It protects against heat loss, noise intrusion, overheating, provides protection against burglary and it can be a beautiful decorative element. By confluence of different types of the glass we can get the best combination of these features.
Insulated glass - protection against the cold - it’s one or two-chamber glazing unit which protect against cold and help heat the room providing thermal comfort. Standard glazing unit, single-chamber glazing unit, consists of two panes. The inner pane (1) is a low-emission glass with invisible to the naked eye layer of precious metals (2) transmitting light and solar energy to the interior, at the same time preventing heat transfer from the room to the outside. Outer pane (4) is a float glass. In the space between the panes is a gas (3), argon in standard or krypton, which can further lower the heat transfer value U. The glass is separated by a spacer (5) filled with hygroscopic granules which absorb moisture. Butyl (6) is applied to the entire length of the frame before it is composite, ensuring the tightness of fixation preventing access for water vapour inside the unit or internal gas escaping from the cavity. The frame can be made of aluminium (standard) or a plastic or a stainless steel so called "Hot box"
One- chamber glazing unit
4 - 16 - 4T
Two-chamber glazing unit Ug=0,7
4T - 12 - 4 - 12 - 4T
Soundproof glass (acoustic) - protection against noise - is possible due to:
- Use of glass with varying thicknesses, a 30% difference in thickness is recommended
- Combining two or more panes of glass with one or more layers of PVB
- Combining two or more panes of glass with special noise suppression foil
Soundproof glazing is depending on the following; construction, size of internal cavity between the glass as well as the type of gas used in the construction and can reach sound insulation levels between Rw-28 dB to Rw-53 dB.
Safety glass - protection against injury - is installed in places with high possibilities of glass breakage and possible injuries by glass shards to the people nearby. Most common technologies in the production of safety glass are:
- Tempered glass, which after a breakage fall into small blunt pieces, being far safer than non safety glass
- Laminated glass, combining two or more pane of glass with one or more layers of PVB. In case of a breakage the glass pieces are held together by the PVB layer. The most common safety glass is a laminated glass 33.1 combining two 3mm panes and 1 PVB layer or 44.1 combining two 4mm panes and 1 PVB layer
Antiburglary glass - protection against burglary - is based on glass lamination technology, the application of several layers of PVB tape. The effectiveness of such a package is dependent on the number of layers used in each glass package. The most common anti-burglary glass is 44.2 which mean two 4mm panes and two PVB layers - this is a class P2 window or 44.4 - two 4mm glass panes and four PVB layers - this is a P4 class window.
Solar control glass
Solar control glass - protection against solar energy - can be divided into:
- Absorption glass - float glass which is blue, green, brown or graphite in colour that absorbs some of the solar energy passing through it helps protect the room against overheating. The light transmittance varies, depending on the thickness and the colour of the glass.
- Reflective glass - a normal (see-through) float glass or blue, green, brown, or graphite colour, where one surface is coated with a metal oxide in order to obtain the proper reflection properties. The reflective layer acts like a mirror reflecting part of the solar energy helping prevent overheating of the room. It also makes it very difficult to determine what is happening inside the room, as during the day light, the ability to look through glass like this is very limited.
Usually reflective glass is much better at protecting against solar energy, than absorption glass is.
Obscure glass (decorative) - privacy glass - This is an excellent solution for windows where it is important to reduce the internal visibility, whilst at the same time maintaining full light transmittance. Obscure glass transmits light levels depending on the depth and nature of the design, and at the same time varying degrees of the internal view. There is a wide range of obscure glass patterns and colours.
Frosted glass (milky)
Self-cleaning glass - clean windows without any washing - is covered with a coating called hydrofoil. Ultraviolet radiation triggers the reaction in which all organic and mineral impurities remaining on the glass are degraded. The little that remains is flushed away by rain water or with a garden hose. The advantage of this glass is that dirt does not stick very firmly to its surface; free water flow allows for quick evaporation which leaves the glass without any stains or watermarks. It is important to remember to regularly flush the surface of the glass with water in the case of a lack of rain.
Self-cleaning glass is mainly recommended for glazing in places directly exposed to sunlight and rain; windows, facades, conservatories, glass roofs. The more sunlight and rain the glass gets, the better the self-cleaning function works. Self-cleaning glass is also especially recommended for glazing in confined areas. It is not, however suitable for indoor use.
Ordinary glass / self-cleaning glass
A two-way pressure valve, in normal conditions, remains tight and does not allow for the exchange of gases in the space between panes. When the pressure difference reaches the value of + / - 80 mbar the valve will open. If the differential pressure changes by + / - 25 mbar the valve will close. Please note that valves like this do not provide the ideal valve pressure equalization, but it allows you to regulate pressure inside the glass unit. It is used in air transport windows, and in the windows installed at high altitudes.