Houses without windows are not built. And the main heat leak in houses has always occurred through the windows. Therefore, we tried to make the windows as small as possible. The development of science and technology today has made it possible to create special glasses, the so-called energy-saving glasses, and on their basis to make energy-saving double-glazed windows.
Heat leaves the premises through modern double-glazed windows to a lesser extent than through any other part of the house. Double-glazed windows fully comply with modern energy saving requirements. Thanks to energy-efficient double-glazed windows, windows in buildings have become an important element of the external and internal design of the premises, even for our harsh climate. Architects are not constrained by the requirement to reduce the glazed area to retain heat, and many modern buildings are decorated with huge areas of windows and stained glass.
The first glass unit was invented in 1934, and in 1970 industrial production of glass units began in the West. A double-glazed window can be called a complex technical product, because its production consists of several parts, the connection of which can only be performed under production conditions on fully automated lines..
Glass manufacturing technologies are in constant development and improvement. Today, low-emission or electrochromic glass is used in energy-efficient glass units. Such glasses are coated with a layer of non-ferrous metals that reflects heat. Glasses in double-glazed windows have perfect transparency, because only high-quality glass is used for production. The use of energy-saving double-glazed windows allows you to reduce heat losses when heating a house by 50%. The use of energy-saving technologies in the production of windows should, first of all, pay attention to the owners of cottages without central heating. Reduced heat loss adds up to tangible money savings over time.
Types of saving glass units
By the number of glasses used in a double-glazed window, single-chamber (from two glasses) and two-chamber (from three glasses) double-glazed windows are distinguished. Glasses are separated by gaps or, as they are called, chambers and placed in special metal frames. The joints are double sealed with a special sealant – silicone gel. The silicone gel has drying properties. Due to the filling of chambers with dry air, the windows do not fog up. To increase energy saving, an inert gas argon is pumped into the chambers, the density of which is higher than the density of air.
Single-chamber double-glazed windows have a thickness of 2.4 cm.Single-chamber double-glazed windows with glass without energy-saving coating (k-layer or i-layer) are used mainly for glazing unheated rooms: verandas, terraces, since at low outside temperatures condensation settles on the glass.
The most convenient and practical are double-glazed windows 4 cm thick. Such a package without condensation can withstand sub-zero temperatures up to 30 degrees. In addition, it has excellent soundproofing properties..
Theoretical aspects of design development
Glasses used in energy-saving glass units are divided into two types:
- k-glass. They have a hard tin oxide coating that is applied to the glass during its production. Such a coating is less susceptible to environmental influences.
- i-glass. It is glass with a so-called “soft” silver coating, applied after industrial glass production. This is a softer coating, but this factor is not very important if the i-layer is applied from the side of the room. i-glass has higher energy-saving characteristics (1.5 times more economical) than k-glass, therefore, predominantly soft coating is used in insulating glass units.
The principle of operation of energy-saving double-glazed windows is that the heat is not absorbed by the glass, but is reflected back into the room by a soft or hard coating.
If the glass is covered with an energy-saving layer, then a single-chamber double-glazed unit is 30% more efficient in saving heat than a two-chamber package with ordinary glasses..
To check if the glass is covered with an energy-saving coating, you can bring a lighter to the glass. Several flames will be reflected in the glass. One of the reeds should not be yellow, but bluish or reddish in color.
To reduce the weight of energy-saving glass units, another type has been developed – a “thermal mirror”. This is a single-chamber double-glazed unit with a special polymer film with a low-emission coating stretched inside the chamber. As a result of placing the film inside the chamber, a two-chamber double-glazed unit is obtained of significantly lower weight, but with the same energy-saving characteristics..