- The structure of double-glazed windows
- Choosing high quality glass
- Filling the air chamber
- What is a spacer
- Energy efficient coated glass
- Energy saving film
- Heated glass
- Electrochromic glass
- Manufacturers and prices
In modern plastic windows, 70% of the total area is allocated to double-glazed windows, therefore, many functions of window systems depend on their quality and efficiency. Double-glazed windows differ from each other depending on the structure and purpose.
There are several types of double-glazed windows:
- energy efficient;
This article will focus specifically on double-glazed windows, the role of which is to preserve thermal energy inside a glazed room – on energy-efficient double-glazed windows.
The structure of double-glazed windows
The structure of a double-glazed window is based on two or more glasses with a spacer around the perimeter. The resulting structure is processed with special glue along the edges, which makes it completely sealed. Air chambers are formed inside the glass. The air chamber is the main element in double-glazed windows, it creates an insurmountable barrier between the outer and heated part of the room, which prevents heat leakage and contributes to more efficient operation of the heating system. Double-glazed windows with one or two air chambers are often used. Experts do not recommend purchasing three-chamber (or more) double-glazed windows, since this is simply not advisable – the heat saving coefficient does not increase from a large number of air chambers, only the cost of a double-glazed window increases. Basically, single-chamber double-glazed windows are used in premises that are not designed for permanent residence – office premises, summer cottages, terraces, etc. Undoubtedly, they can be used in residential premises, for example, balcony blocks, but provided that this is not the main glazing, but secondary. In all other cases, it is customary to use double-glazed windows with two air chambers..
Choosing high quality glass
The marking of glasses for double-glazed windows according to the standard nomenclature has the form “M1”, “M2” and more. The lower the number, the higher the quality of the glass. The main features are its physical properties – the refractive index of light rays and the flat plane of the surface. The transparency of the glass depends on the refractive index, the glass should not distort the appearance of the surrounding space, and the quality of its cutting (under production conditions) and installation depends on how smooth the glass is, which further affects the energy efficiency of the glass unit. When purchasing a double-glazed window, make sure of the availability of high-quality glass by requesting the appropriate documentation from the manufacturer, serious companies will willingly provide you with this information.
Filling the air chamber
There are double-glazed windows in which the air chambers are filled with ordinary air, this technology has a relatively low price, as well as a small heat saving coefficient. In energy-efficient glass units, the air space is filled with argon or krypton. These are inert gases that have a denser molecular structure, due to which the package transmits less heat, thereby keeping it inside the heated room. Krypton is a more expensive gas compared to argon, therefore it is more often used in European countries, in the CIS countries it is generally customary to use argon filling. When buying gas-filled windows, you need to make sure of the quality of the product. At the moment, there is only one way to determine the presence of a gas filler, but it is very expensive and is used only in production, therefore, it is necessary to purchase double-glazed windows from a quality and reliable manufacturer who can provide a quality certificate for its products with the subsequent fulfillment of all warranty obligations.
What is a spacer
The spacer is an important element, thanks to it the glasses are joined together, which makes the glass unit completely sealed, increasing its energy efficiency. The main percentage of the frames is made of shaped aluminum, steel or polymer material, on which illuminated holes are applied. The cavity of these profiles is filled with a hygroscopic desiccant (adsorbent), which absorbs moisture inside the air bag, preventing the windows from fogging from the inside, which often occurs when condensation forms on the glass surface.
Recently, flexible spacers of the new generation have become more commonly used. At the base is still the same aluminum, but the shape of the profile has a wavy structure, which allows the frame to fit more closely to the surface. On top of the profile, a rubber seal is applied, it gives the frame strength and makes the surface smooth. This entire structure is finished on three sides with a water-resistant barrier, which prevents moisture from entering the air chamber. A layer of absorbent substance is applied to the top of the hydro-barrier, this substance completely absorbs all possible moisture from the chamber and gives the glass unit a beautiful finished look. The flexible spacer has an adhesive layer on both sides, thanks to which it is perfectly fixed inside the bag. The glue that forms the basis of this layer is not exposed to the harmful effects of ultraviolet rays, which significantly increases the service life of insulating glass units.
1 – adhesive layer, 2 – absorbent layer, 3 – hydro barrier, 4 – seal, 5 – corrugated aluminum
Recently, the American company Edgetech has offered an alternative to aluminum profiles by manufacturing a spacer made of structured polymer foam. Such a frame, according to the developers, retains heat 900 times better than an aluminum-based frame, which reduces heating costs by about 6%. It is also not exposed to sunlight and has a low aging rate. But, unfortunately, the frames, which are based on polymers, have one significant drawback – due to the design feature, they cannot be placed in a glass unit strictly at right angles, so its edges turn out to be bent in a semicircle, over time such a frame can crawl into the center of the air chamber , which will reduce the energy efficiency of the glass unit and completely spoil the appearance of the window.
Energy efficient coated glass
In order to keep more heat inside the heated room, it is necessary to use double-glazed windows, which have glass with an energy-efficient coating. This coating is a thin layer of silver or nickel ions deposited on the glass surface. The thickness of this layer is a few nanometers. Thanks to the energy-efficient coating, the secondary heat that comes from heated objects does not leave the room, but is reflected back from the surface. The cost of such a double-glazed window increases by only 5%, but it allows you to save heat by 50% more, therefore, in this case, the cost of purchasing it is fully justified.
The process of deposition of metal ions occurs by bombarding atoms on the surface of the glass, therefore, it is necessary to purchase such glass units from trusted manufacturers, since such a procedure requires modern and expensive equipment, as well as huge production areas.
There is a simple way to make sure that you have an energy efficient coating when buying a glass unit, bring a lighter to the glass, if you see a flame with a purple tint in the reflection, this indicates that the glass is really covered with a thin layer of metals.
Another advantage of such glasses is the fact that the glass, which has an energy-efficient coating, will always be several degrees warmer than the others, which will significantly reduce the likelihood of condensation on the surface of the glass unit..
Energy saving film
An alternative to an energy-saving coating can easily be an energy-saving film. It is made using a complex technology and is a multilayer composite using precious and rare earth metals. Its structure allows you to block infrared and ultraviolet radiation, thereby retaining heat in the room 40% more efficiently than conventional double-glazed windows. It transmits ordinary sunlight, which is in the visible range, with minimal losses, with all its energy efficiency, it does not spoil the view from the window. Such a film can be ordered separately and glued to the glass unit yourself. Its cost ranges from $ 20 to $ 30 per square meter, but it significantly reduces heat loss in winter and keeps a pleasant coolness in summer, thereby saving on heating and air conditioning..
As another option for energy-efficient insulating glass units, glasses equipped with an electric heating function can be used. The structure of such glass has heating electrodes around the perimeter or a thin metal mesh on the surface, which heats up when an electric current is passed through it. This tool is auxiliary, not the main one, so you should not think that such glasses can heat the premises. Electric heating is used to eliminate the “cold glass” effect, to eliminate ice or snow edges, and to prevent condensation, thereby increasing the life of the glass unit and its energy efficiency.
In the light of the latest innovations, unusual glasses have appeared, which are based on liquid crystals. In the de-energized state, the arrangement of the crystals is chaotic and the glasses imitate a matte opaque structure, but as soon as the electricity is turned on, the crystals are immediately arranged strictly in a perpendicular order relative to the surface, making the glass absolutely transparent. Thanks to this effect, you can significantly reduce the amount of sunlight on hot days, thereby keeping the room cool..
Manufacturers and prices
On the domestic market, double-glazed windows are presented in all kinds of options. Leading companies present a wide range of choices for every taste. The number of manufacturers is very large, but it is better to make a purchase in large companies, the quality of the product depends on this. Most of the advertised companies, unfortunately, use garages or small hangars as production areas, in such conditions it is impossible to withstand complex technological processes, so opt only for well-known professionals. Do not rush to purchase goods from the first counter company, which beckons with its low prices, a double-glazed unit is a very important functional unit, it cannot be very cheap. The cost of double-glazed windows depends on many parameters, you can calculate it yourself only approximately, for this you need to use the table below. For a more detailed calculation of the price, you should contact the managers of the manufacturer for help..
Glass units made of M1 glass Single chamber Bicameral formula price in USD. formula price in USD. 4-16-4 thirty 4-6-4-6-4 24 4-16-5 50 4-10-4-10-4 26 4-14-6 25 4-12-4-12-4 27 5-14-5 27 4-8-4-8-4 33 6-12-6 32 6-10-6-10-6 44 Double-glazed windows with energy-saving glass Single chamber Bicameral formula price in USD. formula price in USD. 6-16-6K 47 4-6-4-6-4K 37 4-16-6K 31 6-10-4-10-4K 44 4-16-4K 32 6-10-6-10-6K 54 Double-glazed windows with triplex Installation of shpros in double-glazed windows for 1 lm: formula price in USD. Colour thickness, mm price in USD. 4-16-3.1.3 from 43 white 8/25 7 4-16-4.1.4 from 53 white 18 6 6-16-3.1.3 from 48 gold 8 7 6-16-4.1.4 from 57 double-sided 18 7
The cost of windows with energy efficient double-glazed windows is higher than that of conventional ones, but their use will lead to significant savings in funds spent on heating the premises. Thus, energy-efficient double-glazed windows independently pay off the costs of their purchase. Also, the feasibility of using energy efficient double-glazed windows can be calculated using a special online calculator.