- The history of the development of the window industry
- Theoretical aspects
- Types of energy-saving double-glazed windows
The question of the rational use of nature resources is very relevant today all over the world, and in this regard, energy-saving technologies and structures are widely introduced and used..
Energy-saving equipment and the energy-efficient materials used, installed in apartments and private houses, can significantly reduce the costs of thermal energy sources, such as gas and electricity, and this, in turn, saves a lot of money from the family budget.
Energy-saving technologies are used both in the construction of a house and in repair work. For example, window structures made using energy-saving technologies reduce heat losses several times, because the total area of all windows in an apartment is considerable.
The history of the development of the window industry
The window industry has been developing at a fairly rapid pace for the past 50 years. A few decades ago, the window structure was a wooden frame with one layer of glass – the thermal conductivity of such windows is very high, and, therefore, there was practically no protection against cold penetration into the room.
A little later, double-glazed windows appeared, that is, the window structure no longer consisted of one glass, but of two, and there was an air gap between them. This made it possible to halve the thermal conductivity coefficient. Years later, sealed glass units appeared on the market, having several interconnected chambers, and the space between them was no longer filled with air, but with an inert gas, usually argon. Such windows not only prevented the penetration of cold into the room, but also prevented the loss of thermal energy..
This evolution of window construction can be explained quite simply based on the laws of physics. As you know, there are three ways to distribute heat: radiation, convection and heat conduction. Therefore, to reduce heat loss through the construction of windows, each of them must have a barrier. This problem is solved by a double-glazed window with one or more cameras..
Argon is now used to fill the space between the glasses in order to reduce convection, since in comparison with air molecules, argon particles move much slower, that is, the rate of heat transfer from one glass to another slows down.
In practice, everything is also extremely simple: the most common double-glazed windows consist of two glass panels 4 mm thick, the space between them is 16 mm filled with argon, and to prevent the penetration of infrared radiation, one of the glasses is covered with a low-emission coating, and sunlight passes through such windows without hindrance. … These windows are called energy efficient, but ordinary windows with a wooden frame and ordinary glass do not correspond to this concept, it applies only to PVC windows with energy saving glass.
Types of energy-saving double-glazed windows
Windows with two or more chambers are considered the most effective in terms of providing comfort and warmth, while the maximum heat savings are provided by windows in which the distance between the glasses is different.
Energy-saving glass installed in a glass unit must meet a number of specific requirements. Such glasses are made using a special technology: a thin layer of metal oxide is applied to ordinary glass, as a result, a film that is invisible to the human eye is formed on the glass surface, which protects the room from harmful ultraviolet radiation, but does not prevent the penetration of thermal energy.
Depending on the technology of applying the metal oxide, there are two types of energy-saving glasses:
- I-glass – has a soft coating that provides the required level of protection against harmful radiation and a high coefficient of thermal protection The only significant drawback of I-glasses can be considered a short service life, not exceeding 10 years;
- K-glass – the coefficient of thermal protection of this type of glass is one and a half times lower, but the hard coating is more resistant to external influences, and therefore the service life of K-glass is longer.
The use of such glasses reduces heat loss in the winter, however, to prevent heating of the room in the summer, it is necessary to use additional technologies. To reflect the sun’s rays, special reflective glasses are used to prevent heating of the room and objects in the room. For the same purpose, tinted glasses can be used, but they strongly distort colors and heat up. To achieve the maximum effect of keeping warm and prevent heating from the summer sun, it is advisable to use combined multifunctional glasses, which retain heat in winter and do not allow the room to heat up in summer.