Request an offer Pitfalls of energy-saving glass

General information about glass

Energy-saving glass is the simplest double-glazed window in appearance, which reduces heat exchange between the outside air and the room. This technology helps maintain optimal conditions both in winter and summer. At the same time, minimal use of additional equipment is planned. Now there are several options that allow you to improve the quality of glass:

1. The space between the windows is filled with argon.
2. Sputtered film is applied.
3. Part of the outer surface is sprayed.

Regardless of which method is used to obtain the effect, the result will be identical. Here the throughput deteriorates, which leads to small temperature differences. But at the same time, the window can bring results both in winter and in summer. At the same time, such windows now have both their advantages and disadvantages. We need to talk about them, because they will significantly influence your purchasing choice.

Disadvantages of energy-efficient windows

Rice. 8. energy saving film

The biggest disadvantage of smart windows is their price. Initially, spraying was applied at the production stage, which required special equipment and trained specialists. But even this does not make the procedure easier. When using metal oxide in the glass manufacturing process, there is a very high probability of defects when the substance is distributed unevenly. This greatly reduces the "warm" properties. Due to the high complexity of working with spraying during the production process, this method has become unpopular. But other options are also not cheap and have their drawbacks.

“Reflective” glass cannot be installed on the sunny side of the building. This leads to faster wear of the coating and deterioration of their original properties. There is a high probability of not only destruction of the protective layer, but also of the entire window structure. And this is in cases where a coating on the surface or filling the chamber with gas was used to preserve heat. Using film has an even shorter shelf life. This “tinting” is applied to both sides of the glass, but after 10 years it loses its usefulness, although the PVC structures themselves last much longer.

Spraying features

No matter how many cameras there are in the window system, spraying is done only on one glass and only on one side. To ensure longer service life, the treated side is usually located inside the first chamber, on the street side. There are several varieties of layers used to save energy.

One of the most common options is k-coating. It is considered hard because it has increased strength and resistance to mechanical damage. Created using metal oxides. For application, the surface is first heated to a very high temperature, so the least resource-intensive spraying process is during the manufacture of a double-glazed window.

An alternative option is i-coating of two layers. It is destroyed to a greater extent under the influence of aggressive mechanical factors, therefore it is classified as soft. First, a silver layer is sprayed, for which the glass must be completely prepared and placed in a vacuum. The second layer – protective – consists of titanium oxide.

Is it worth pumping inert gas into the internal chambers?

Myths around energy-saving windows can sometimes misinform even those who have already made a clear decision to order such products. One of the most common misconceptions is that argon can significantly increase their efficiency. On the one hand, the information is completely true - inert gas retains heat well. On the other hand, its efficiency in a specific situation is not as high as some sellers promise. The logic of manufacturers is absolutely clear and lies in the fact that it is personally beneficial for them to sell an additional service to clients. However, does the window customer need this? To avoid making mistakes and wasting money, it is recommended to take an individual approach to the need to use inert gas. In some cases, it makes sense to pump in argon, while in others, it is more advisable to use a double-glazed window with an energy-efficient coating. The optimal type of double-glazed window can only be determined by comparing the heat transfer resistance coefficients of different modifications.

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Type of glass unitHeat transfer resistance coefficient

These data clearly show that inert gas in all cases increases the efficiency of windows by approximately 10%. For those who want to fill energy-saving windows with argon, expert reviews can be crucial. After all, these are the people who work in the region and have reliable information about what level of thermal insulation is optimal for specific climatic conditions. At the same time, the warmest double-glazed windows with 2 chambers and inert gas, due to high prices and weight, are not yet in high demand in regions with a temperate climate.

Glass

The design of a multifunctional double-glazed window (MF) includes glass with a special multilayer coating, which has the following structure based on the sandwich principle:

• The middle functional layer is made of silver or chrome. Provides effective reflection of thermal radiation in the short and long wavelength range.
• Protective layers cover the main one on both sides. They prevent mechanical and chemical damage to the silver coating and also absorb short-wave radiation.
• The outermost upper and lower layers are made of nitrites or oxides. Characteristics such as transmittance, specularity and color of glass depend on their chemical composition. Manufacturers offer multi-colored products for the implementation of design glazing projects.

Spraying is applied to the inner surface (inside the glass unit).
Multilayer coating is the main fundamental difference between multifunctional glass and other types of similar products. It is applied in a factory using the magnetron method using vacuum equipment. The coating effectively prevents heat from penetrating the glass in both directions:

• During the cold period, 60% of infrared radiation from radiators and household heating appliances is reflected and returned to the room;
• In summer, it prevents heat from entering the room from outside, reflecting up to 58% of sunlight.

The operating principle of a multifunctional coating is not to prevent the penetration of light, but to absorb and reflect waves of a certain length. Light filters function in a similar way. We can say that MF is an improved energy-saving double-glazed window that has received additional impact resistance and tinting.

The difference between multifunctional and energy-saving double glazing

Such product indicators help to significantly save on space heating in winter by reducing heat loss and air conditioning in summer. In buildings equipped with MF, it is much easier to maintain a comfortable microclimate. It is noticeably warmer there in the cold season and cooler in the summer.

To learn how such double-glazed windows are produced, watch our video:

Thermophysical explanation

Someone will rightly note that not even three years have passed since I changed the windows, but they are no longer relevant, they are not the best. What now, as soon as a new product has appeared, should you immediately spend money on it? I’ll buy a film to save heat and that’s it. Although not an ideal option, it has the right to life.

Let's take a look at how thermal physics is integrated into the design of the new product. Maybe this will convince, the person will decide for himself whether it is necessary to change or not, whether the new product is worth the money or not. Moreover, let us remind you that classical wall insulation technologies are not applicable for window openings. But the advantage of new window systems is that by reducing heat leakage, the manufacturer increases the access to light.

Let's return to the physical explanation. Thermal energy travels either in the form of radiation or convection.

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Radiation - infrared spectrum, is determined by the level of surface heating. Convection is the exchange of heat between hot and cold.

Simple glass does not interfere with the infrared ray, that is, you can stick a film on it, it will reduce the release of hot heat to the street. When making energy-saving bags, at the production stage the glass is coated with non-ferrous metal sulfide and silver plating is done. They can apply a film.

The treated surface increases the level of reflection of infrared radiation by 80%. The treated glass surface transmits 72% of light, the remaining 28% does not affect perception. In summer, the surface will reflect up to 45% of solar radiation.

What it is

This material is a double-glazed window with a special multi-layer coating. It is applied to the glass surface during deep-vacuum magnetron processing. In this case, the coating is completely environmentally friendly. Highly selective silver becomes the main functional layer. Double-glazed windows created using this technology help to significantly reduce the penetration of solar radiation into an office or apartment.

At the same time, the light transmission capacity remains at the highest level. In addition, the use of such windows makes it possible to reduce heating and air conditioning costs, since they have improved thermal insulation. In this regard, the circulation of cold air in the double-glazed window is reduced, eliminating the possibility of condensation forming on the inner glass during the cold season. In humid and hot weather, condensation will also not appear on the outer glass.

Multifunctional double-glazed windows allow you to effectively maintain an optimal indoor microclimate. They become a kind of mirror that reflects heat and light in both directions. Due to this property, glass works well in cold and hot weather without compromising light transmission. Multifunctional double-glazed windows help save on electricity. After all, heat loss will be minimal, you will not have to spend money on additional heating of the space. It is by these parameters that you can distinguish a multifunctional double-glazed window from a regular one.

Reviews from experts and users

Energy-saving windows receive positive reviews from professionals and ordinary users. Most of them note that after installing windows, the microclimate in the room has improved, in winter there is no need to turn on additional heating devices and the windows do not fog up, and in summer the building is cool.

There are also negative reviews from users who complain that they did not feel much difference between energy-saving and conventional plastic windows. It is important to remember that the thermal insulation properties of a window are made up of many components, none of which are insignificant or minor. The type of glass unit, the quality of the profile, the tightness of the assembly, compliance with installation technology - all points are equally important. If any of the links is broken, then the efficiency of the entire structure drops sharply or is reduced to zero.

For example, if a low-quality profile was used for windows with energy-saving glass, or the finished products were installed incorrectly, then the consumer will not feel any benefits of the technological innovation.

Don't skimp on window profiles!

Energy-saving double-glazed windows will help create comfortable indoor conditions at any time of the year and significantly reduce heating costs. Such products are definitely recommended for most of Russia, especially for middle and northern latitudes. In the southernmost regions, preference should be given to multifunctional double-glazed windows with additional tinting.

What do professionals think about energy-saving double-glazed windows:

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2 comments on “What are energy-saving double-glazed windows and is it worth installing them? »

I live in the Stavropol region. At the end of summer, energy-saving windows were installed. Double-glazed windows coated with silver. Everything is beautiful. We just haven’t had time to evaluate their heat-saving properties yet. I read that flowers are comfortable with these windows. I just noticed that my flowers began to lack light, the leaves even turn away from the window and seem to be looking for light from opposite windows from other rooms. They are missing some rays.

K-glass is often found in greenhouses, winter gardens and other structures that have specific design and operational requirements. According to data from the photosynthesis department of the Botanical Institute. V.L. Komarov RAS, the growth of indoor plants is influenced by a lack of moisture, excess or lack of heat for each type of plant separately, as well as a lack of sunlight in the visible part of the spectrum. Specialists at this center do not note the impact of using low-emissivity glass in double-glazed windows for the following reasons: 1. According to the Glaverbell concern, low-emissivity coating, while maintaining a high degree of transparency in the visible part of the optical spectrum, provides a high degree of reflection in the infrared range (95%). The thickness of this coating is so thin that it is completely transparent to visible light and sunlight. 2. Comparative data on ultraviolet radiation transmission: Planibel 4 mm - 16 mm Air - 4 mm Planibel: Ultraviolet transmission UV(%) 47 Planibel 4 mm - 16 mm Air - 4 mm Planibel Top N: Ultraviolet transmission UV(%) 21 Thus Thus, the ultraviolet transmission of low-emissivity glass is two times less than that of ordinary glass, but this circumstance does not have a significant effect on indoor plants. The lack of ultraviolet radiation is significant for high-mountainous plants, to increase the growth of which the St. Petersburg Vavilov Institute (VNII of Plant Growing) recommends periodic irradiation of plants with ultraviolet rays in the middle range of the ultraviolet spectrum. The synthesis of some biologically active substances (alkaloids, terpenes, essential oils) also increases significantly. But we don’t grow hemp, so this property is useless. 3. Glass with a low-emissivity coating acts like a thermal mirror, capable of reflecting back over 90% of thermal energy (no matter where it comes from), protecting the room from overheating in the summer, and from hypothermia in the winter. Thus, excess or lack of heat is regulated in the room, preventing the “greenhouse effect”, which also has a beneficial effect on indoor plants, eliminating their overheating or hypothermia, and also significantly reduces the risk of fading of materials. However, all plants (even indoor plants) are different - for example, palm trees love humidity and twilight, and roses do not tolerate excess humidity and direct sunlight, so it is best to consult with specialists on how to care for each plant.

How to determine energy-saving glass?

Choosing glass for a double-glazed window.

Glass , like any building materials, has certain mechanical properties. The main advantage over other materials is its transparency. Glass also differs in light and thermal characteristics. For example, clear glass, most often used in glazing, provides a high degree of light transmission (about 89%) and thermal conductivity. This means that glass perfectly transmits both heat and light; accordingly, a room with such glazing will be light and hot in the summer and light but cold in the winter. This is why single glazing is only used in cold rooms. The glass is assembled into a double-glazed window using a special sealant and spacer frames. Its light transmission and heat-saving characteristics largely depend on what glass is used for a double-glazed window. There are many types of glass, we will look at the most common:

Safety glass. This is glass that does not harm a person at the moment of destruction. Currently, there are several types of such glass, let's consider the two most popular: 1. Tempered glass . When producing glass, it is heated in a special furnace to a temperature of 600 degrees. C and cool quickly. Such glass is five times stronger than ordinary glass; when broken, it crumbles into small fragments that do not have sharp edges. 2. Laminated glass . Such glass is produced by gluing two or three sheets of glass using a polymer resin or a colorless special film. The result is very strong glass, which is widely used not only in construction, but also in the automotive industry (car windshields are produced in the same way). Such glass is called multilayer or Triplex. This is a very durable glass, and when broken, it does not shatter into fragments; they remain on the film.

Colored or tinted glass. This is a type of glass designed primarily to protect against solar heat entering a room while maintaining transparency. Tinted glass is obtained in several ways: 1. Tinted in mass . It is obtained during the glass manufacturing process by adding special additives to the glass composition. There are bronze, gray, green and blue. 2. Laminated with film . A colored film is glued to the glass; nowadays there are a lot of shades, so you can get glass of almost any color. In addition, such glass is much stronger than tinted glass. There are also negative aspects to tinted windows. Such glass has higher heat absorption than transparent glass, so it can collapse under thermal stress. Tinted glass is installed in a double-glazed window from the outside so that it is cooled by the flow of outside air. For example, green glass blocks up to 65% of sunlight, while the heat absorption of such glass is 36%. Bronze glass retains up to 60% of light and up to 68% of heat. The destruction of colored glass can also be caused by microcracks that form on the edge of the glass after cutting it. Therefore, when using colored glass in areas with hot climates, in order to increase their mechanical and thermal resistance, they must be tempered and edge treated.

The difference between energy-saving double-glazed windows and conventional ones

Energy-saving double-glazed windows are the number one choice among consumers today. They are a certain type of glazing that perfectly retains heat in a room.

Unlike conventional double-glazed windows, double-glazed windows with energy-saving glass are made from special glass, on top of which a certain low-emissivity coating is applied. This allows short-wave solar energy to pass unhindered directly into the interior of the room, and heat flows tending outward to be freely reflected, thus preserving heat.

There are several types of heat-saving windows:

1. Energy-saving double-glazed windows with argon. They contain a special gas that creates a certain pressure inside the system and prevents heat from escaping outside; 2. Energy-saving single-chamber double-glazed windows. Has one camera. 3. Energy-saving double-glazed windows. Represented by two cameras respectively. The production of energy-saving double-glazed windows implies the use of several types of glass in the process of their creation: - I-glass with an improved energy-saving effect, absolutely transparent; - K-glass, which has a metal oxide on its surface, has a lower degree of transparency.

Energy-saving double-glazed windows technical characteristics

They depend on the type of glass used in the manufacturing process and the number of chambers. They are determined by the type of glass unit and heat transfer resistance. Drawing an analogy with an ordinary single-chamber window, it can be noted that the level of its resistance to heat transfer is 0.32, while energy-saving single-chamber double-glazed windows are 0.59; two-chamber regular - 0.47, two-chamber energy-saving - 0.64. Thus, we can say that, unlike a regular one, the energy-saving package is 1.5 - 2 times “warmer”

Before checking an energy-saving double-glazed window, it is necessary to check the presence of such an important indicator as the marking of energy-saving double-glazed windows, which indicates the type of glass used, the number of chambers and the level of energy saving. This is a mandatory condition indicating their high level, quality, practicality and durability of performance characteristics

A single-chamber energy-saving double-glazed window or a double-chamber one saves approximately 38-40% more heat than conventional metal-plastic windows at the same cost!

Many manufacturers of energy-saving double-glazed windows, unlike us, offer their customers deliberately inflated prices. Our price for energy-saving double-glazed windows is the personification of democracy and acceptability for various categories of the population. If you are interested in reviews of energy-saving double-glazed windows, how to determine its level of thermal energy conservation, how to distinguish an energy-saving double-glazed window from a regular one, or how to accurately and correctly install an energy-saving double-glazed window, call our consultants at the phone numbers listed on the website, who will provide you with explanations in an accessible form. Or you can send a request for calculation to our managers and they will call you back and tell you the cost of your window.

According to research, windows with energy-saving double-glazed windows pay for themselves in 1 season. After that, you get net savings for the rest of the time.

Energy-saving double-glazed windows purchased from us are distinguished by: - ​​high quality; — reliability; — practicality; - aesthetics; — high degree of functionality; — excellent heat-saving properties; - good fittings from the world's leading manufacturers.

We will provide you with high-quality service, the fastest window production and a long warranty period.

Benefits of energy-saving windows

Rice. 3. how energy-saving windows work

“Hot” products are quite expensive. Therefore, when the client is faced with the question of choosing products, preference is often given to standard varieties. They look completely identical in appearance, but clients themselves do not always understand what the difference is between a cheap and expensive item.

Thermal insulation

Rice. 4. thermal insulation indicators of different types of windows

The main advantage of improved windows is their reflective ability. Regular glass heats up and cools down quickly. Because of this, in winter, when heating systems operate at full capacity, part of the heat is used to heat the street. That is, resources are wasted. The special coating minimizes the radiation of heat into the external environment, thereby maintaining the optimally high temperature at home. Under such conditions, it is easier to maintain a comfortable temperature, and the batteries do not have to work at full capacity.

In summer, the room will be protected from overheating. Although sunlight will penetrate into the apartment, most of the heat will be reflected to the outside environment. Such a device does not guarantee that the apartment will be cooler than outside, but the room will heat up much more slowly in hot weather.

A light weight

Rice. 5. differences between double-glazed windows with one or two chambers

Modifications that help keep the room warm in winter do not carry additional weight, and can be applied to different variations of double-glazed windows. This means that the single-chamber variety with a special coating will be even hotter than the standard two-chamber design. A single-chamber profile with improvements will be warmer than a two-chamber profile by 20 percent or more.

The single-chamber profile is much lighter than its advanced counterparts with two or even three chambers, but thanks to the coating, it is more reliable and economical in all respects. This design is suitable for installation in any home, although a two-chamber profile is not always suitable for installation on “light” walls.

The weight of the structure is not related to its saving properties, because applying a film or filling the chamber with gas is possible not only with single-chamber products, but also with other types of double-glazed windows. The advantage is that you can use a lighter product and get excellent results.

No condensation

Rice. 6. condensation on the window

Condensation occurs due to temperature changes in winter outside and at home. Regular window lenses cool quickly, so when they encounter warm air and high indoor humidity, water droplets appear on the surface. Energy-saving products will not be as cold in winter as standard ones. Therefore, the problem with temperature changes, which causes glass fogging, disappears.

Burnout protection

Rice. 7. types of tinted glass

Color fading on fabrics, furniture, wallpaper and paintings occurs due to too bright light. Therefore, in most museums, rare exhibits are stored in rooms without windows and with special lamps. However, the reflective ability of the spraying not only stops heat transfer, but also reduces the illumination of the room. The change is unlikely to seem noticeable to a person, but most things, even if they are constantly on the windowsill on the illuminated side, will retain their bright shade longer.

And why do we need gas?

If, instead of ordinary air, an inert gas is pumped between the glasses, heat will be transferred at a lower speed, since these substances are characterized by low thermal conductivity. In addition, the glass filler will be completely devoid of water molecules capable of forming condensation. Water is an excellent conductor of heat, and the less it is, the more efficiently energy is stored.

Is it worth overpaying for window packages assembled using this technology? It is believed that argon reduces energy losses by approximately one tenth, which in reality is very difficult for an ordinary person to notice. Most users note that they did not feel any significant difference. On the other hand, it cannot be denied that the use of special gases improves the performance of window systems, and with a high level of heat retention can provide additional improvement. But when installing a regular plastic window, filling the chambers with argon or krypton does not bring any real benefit - the energy losses are large enough that a tenth does not play any significant role.

Energy saving window frame

The frame of an energy-saving window is made of a low thermal conductivity material – polymer.

High-quality polymer has low thermal conductivity and is resistant to external influences.

Wooden double-glazed window frames are also used.

Such frames have nothing in common with the old windows that were installed in the last century.

Nowadays this is treated wood, which serves as a good heat insulator, does not dry out, and provides a good sealing of the window opening.

Differences from conventional plastic windows

First of all, energy-saving double-glazed windows are distinguished by their high ability to retain heat indoors, while outwardly they are almost no different from conventional windows. There are two production technologies; products may be designated by the letters “k” or “i”.

Technology “k” appeared earlier, has some shortcomings, and is quite rare to find on the modern market. “i” glass is more popular because it has a higher ability to retain heat. They are made from more modern materials. The glass undergoes a special treatment, during which vacuum deposition of metal is applied to it. The thickness of such a layer is only 0.08-0.12 microns, which remains invisible to the human eye.

Energy-saving glass is most often coated with titanium oxide and silver, due to which it acquires the ability to repel heat without releasing it into the external environment. In addition, the glass itself heats up a little, so it does not freeze.

In addition to factory spraying, materials can have a film glued on top to save energy. Manufacturers provide a guarantee for heat-reflecting film: it is 15 years. After this, it is believed that the window performance will become close to a conventional double-glazed window. The film is usually coated with layers of nickel, chromium, silver, and gold. It can be used separately, sticking to any structure.

How to choose the right PVC profile and what types there are, read our material on the website.

How and where double glazing is used is described in our article “Using double glazing for the home.”

Metal-plastic windows

Now about metal-plastic windows.

Metal-plastic windows

Everything is simple here, it’s a PVC double-glazed window, but an additional metal profile is installed in the frame for reinforcement.

The design of such a window is more rigid.

Such windows should be installed where deforming loads on the frame are possible.

There are also aluminum windows.

The profile and frame of this window are made of aluminum alloy.

This profile is the most durable; the window will last one and a half times longer than PVC.

Manufacturers claim a service life of almost 100 years.

The price of an aluminum profile is higher, the manufacturing technology is more complex.

The profile is durable and aesthetic.

There are also disadvantages to such windows.

Metal is a good conductor of heat.

To insulate an aluminum profile, which is also multi-chamber (like PVC), the cavity is filled with insulation.

Only insulated aluminum profiles can be classified as energy-saving windows.

If we compare all these technologies, the most energy-saving are PVC windows and modern wooden windows with installed multi-chamber double-glazed windows.

That is why energy-saving glass began to be used on such structures.

Where are energy-saving windows made?

Who produces energy-saving windows

There are many manufacturers of energy-saving windows in Russia and the world.

A responsible manufacturer indicates in the product documentation the type of coating, what gas is used in the internal cavity and the material of the window profile.

How does energy-saving double glazing work?

The energy-saving properties of double-glazed windows are determined mainly by the unique qualities of the glass used (k, i, iM). These materials have the property of reflecting heat in the direction of radiation. Radiators, heating appliances, household appliances and even the human body are sources of heat in the form of long infrared waves. Low-emissivity glass as part of a double-glazed window returns heat flow from household appliances into the room, and from the sun, heated asphalt and buildings to the street.

At the same time, short electromagnetic waves of sunlight enter the room unhindered. A room with such windows is warmer in winter and cooler in summer, and the level of illumination is almost the same as when using conventional windows.

The types of glass used for the manufacture of energy-saving double-glazed windows differ in the type of low-emission coating, the technology of its application, and, as a result, technical and operational characteristics.

Recommendations

At the ordering stage, you must immediately find out what types of savings technology the company provides to consumers.

When accepting the finished product, it is important to read the markings on the glass.

1. The letter “m” means that plain glass was used in production.
2. “K” or “i” correspond to the type of spraying used, soft or hard.
3. The presence of film is marked with the sign “pl”.
4. "Ar" is present if argon is used as filler.
5. If there is no marking, there is air inside.

After a detailed review of the characteristics of energy-saving windows, it is easy to make a choice in favor of the appropriate type. In this case, you need to take into account the financial capabilities and features of the premises.

How to determine an energy-saving double-glazed window when purchasing

If in a regular double-glazed window the glass is simply sealed, there is a frame between them, and they are filled with sealant around the perimeter. The glass unit with energy-saving glass contains inert gas. Argon is used most often. It is pumped between the glasses and prevents them from freezing in winter.

You should pay attention to the labeling. It is significantly different for an energy-saving double-glazed window

The regular one is marked 4-16-3, and the energy-saving one is 4-16 Ar-4I.

The marking of energy-saving double-glazed windows in the following example can be deciphered as follows: Ar10-4M1-Ar10-I4, we have a two-chamber double-glazed window filled with argon, the thickness of one sheet is 4 mm, one of them has an energy-saving I-coating applied to it.

In Russian climatic conditions, energy-saving glass allows you to install a single-chamber double-glazed window, instead of the usual two- or three-chamber one, which is also beneficial. And proper care of plastic windows will allow them to last for decades.

To check whether a double-glazed window is energy-saving, you will need to bring a flame to it. To do this, just light a lighter. If the glass is ordinary, then the color of the flame will not change in reflection.

If the double-glazed window is energy-saving, then in the reflection of one of the glare of the flame a reddish tint appears. This is the most affordable way to check a double-glazed window for energy saving.

Checking a double-glazed window for energy saving can also be carried out using other methods. One of them is called the Flare Method. If you look at the glass at an angle, you can easily notice a bluish-violet tint on its surface, like on a car windshield.

The use of the “scientific method” is not accessible to everyone. It requires the use of special expensive devices. High-precision equipment can accurately check whether the glass has an energy-saving coating, what the thickness of the glass is, and even derive the formula for the glass unit.

Today, such devices are available to large construction organizations, whose immediate task is to constantly monitor the quality of work of window companies performing glazing of objects.

When going to a hardware store, you need to take a fire source with you. Now, knowing how to test an energy-saving window with a lighter, you can easily put this into practice.

For which buildings and premises is it suitable?

Since the 1990s, standard plastic windows began to be installed en masse in homes. This made it possible to significantly reduce the level of heat loss in buildings. When replacing with energy-saving designs, there is an effect, but not as significant.

Such structures should be installed if the glazing area of ​​the house is at least 40%. In multi-storey glass buildings using heat-saving spraying, you can save up to 20% of heat.

The effectiveness of using energy-saving windows will also be extremely low if the general condition of the house does not meet thermal insulation standards. This option is suitable for premises where everything has already been provided for in terms of energy saving (the building’s energy efficiency class is not lower than B+).

In apartment buildings with central heating, it is effective to install “warm” windows on the north side. They are also useful if the building has heat problems.

In an individual house, such designs will save heating costs.

The tightness of an energy-saving window prevents outside air from entering the room. To maintain the required level of humidity and a favorable microclimate, you need a good ventilation system.

Double-chamber energy-saving double-glazed windows are effective in regions with harsh climatic conditions. They can also be installed on the side of noisy streets.

Comparison of technical characteristics of double-glazed windows

In order to really understand the difference in energy saving between a conventional double-glazed window and a heat-saving one, for example, you can take two options:

- a single-chamber standard double-glazed window with a thickness of 24 mm with a formula of 4m?-16-4m? has an R-factor? (heat transfer resistance) - 0.3 m2°C/W. When low-emissivity glass is installed in it, this figure doubles.

- a two-chamber standard double-glazed window with ordinary glass and having a thickness of 32 mm (4m?-8-4m?-8-4m?), has a coefficient R? equal to 0.49 m2°C/W. If you install heat-saving glass in it, the parameter rises to 0.88 m2°C/W.

Notes on formulas:

4m? - means glass having a thickness of 4 mm, grade M1;

numbers 16 and 8 are the width of the spacer frame.

That is, instead of a double-chamber 32 mm double-glazed window, you can install a single-chamber 24 mm with low-emissivity glass. Moreover, the weight of the structure will decrease by about 10 kg per 1 sq. meter.

The only disadvantage of such a replacement may be sound insulation, since sprayed glass dampens sounds, just like regular glass. The difference in sound insulation will be 24 dB. versus 37 dB. for three glasses.

Why are some types of energy-saving glass impossible to distinguish?

The best way to determine the presence of special glass is to use all three methods. There are serious reasons for this.

— Determining an energy-saving double-glazed window by the color of the flame does not give a 100% accurate result

Depending on the type of spraying and its functional features, the color of the flame may differ slightly and is indistinguishable to the eye. In particular, during the experiment it was not possible to determine multifunctional double-glazed windows by the color of the flame.

— Checking with a detector indicates the presence of coating, but does not determine the type

The second method of identifying an energy-saving coating, although more accurate, is not specific. In addition, special devices for assessing the presence of energy-saving glass are not sold in regular stores. A visit from a specialist to carry out diagnostics using a detection device will cost about 3,000 rubles.

— Thermal imaging examination is indicative of comparison and knowledge of formulas

The third method does not give an answer about the type of double-glazed window, but can give an assessment of its properties. To do this, it is enough to know the temperature outside and have a heat map of the window opening obtained using a thermal imager. A real assessment of efficiency is the advantage of using a thermal imager (compared to assessing the presence of a metal layer on glass).

Varieties, method of determining energy-saving double-glazed windows

Most often, there is air between the glasses of a simple double-glazed window. The energy-saving package is filled with inert gas; most often it is argon. Thanks to this technology, the glass does not freeze or fog up when there is a difference in temperature outside and inside the room.

When choosing a design, carefully study the markings. A regular window is designated by the following combination: 4-16-3, a double-glazed window with energy-saving glass is designated as 4-16 Ar-4I. The last letter indicates that a special coating has been applied to the glass. The combination Ar indicates the presence of argon between the glasses. Installing such glass can significantly save money, since a single-chamber energy-saving kit is an analogue of a three-chamber plastic window. The design is durable and can last no less than simple windows from leading manufacturers.

Looking for plastic windows? Read what are the advantages and disadvantages of Funke Kunstoffe profiles.

VEKA windows have long been very popular and many have already purchased them. Read reviews about VEKA windows in our material on the website.

Advantages and disadvantages

Among the main advantages of energy-saving designs it is worth highlighting:

• condensation does not form on the glass - the temperature of the inner glass does not allow the air in the room to pass the dew point upon contact with it, the outer glass also does not freeze in cold weather;
• in the hot season, hot air does not penetrate through the windows, you can save on air conditioning;
• comfortable temperature all year round - warm in winter, cool in summer;
• furniture upholstery, floor coverings, paints and wallpaper on the walls fade more slowly.

Even a single-chamber energy-saving double-glazed window can provide good heat saving parameters.

Among the relative disadvantages is the high cost of energy-saving window designs. Energy-saving spraying on glass may also lose its technical characteristics if the glass unit gradually depressurizes. Manufacturers set the service life of “warm” glass to be the same as that of the entire double-glazed window – 20-25 years.

What is a double-glazed window with energy-saving glass?

Energy-saving glass appeared on the market recently, but has already gained popularity. Thanks to the installation of “K” and “l” glass, the performance characteristics of the double-glazed window are significantly improved.

It is distinguished by increased heat conservation. It should be noted that glass is rapidly being replaced by glass produced using more recent technology.

Energy-saving “i” glass is obtained by vacuum deposition of a thin layer of metal onto previously prepared glass. Moreover, its thickness does not exceed 0.08-0.12 microns.

The film is practically invisible, and the heat-reflecting characteristics are quite high. Titanium oxide and silver are mainly used as metal when applying a heat-reflecting layer.

If we consider energy-saving double-glazed windows with heat-reflecting films, it should be noted that they can be guaranteed to be used for no more than 15 years.

In terms of durability, they are clearly inferior to similar products that have metal layers. The film contains a thin layer of chromium, nickel, gold, and silver. It is often used to improve the properties of old windows.

If we consider the design of the window, it becomes obvious that the double-glazed window takes up a lot of space. Therefore, how comfortable the climate will be maintained in the house largely depends on it.

Double-glazed windows with energy-saving glass are highly effective for saving both energy and money. If we compare it with a conventional two-chamber double-glazed window, it consists of two glasses, one of which has a low-emission coating applied, while the double-chamber one consists of 3 glasses and 2 air chambers formed between them.

In winter, energy-saving windows guarantee heat savings, and in summer they protect the room from heat.

Soviet windows

Soviet windows, wooden, without insulation

“Old” wooden windows, without insulation.

In houses and buildings that were built before 2000, such windows were installed.

Let's talk about their device.

The frame is made of solid pine wood, painted white, the same window profile.

They installed two glasses and provided the ability to open the sash to wash the glass from the inside.

The windows were not sealed; dust got inside.

The glass was inserted into a wooden frame simply into a groove and secured with a wooden strip.

Such a window did not retain heat well.

Before each winter, the windows had to be insulated with foam rubber and the joints sealed with paper.

Functions

1. What is energy-saving glass and why is it needed??

This is ordinary glass with a thin coating, which has limited transparency in the infrared part of the spectrum (corresponding to thermal radiation). Reflection of IR rays can significantly reduce heat loss in winter and heating of the room through windows in summer.

1. Does the energy-saving layer affect heat transfer due to convection?

Spraying has no effect on convection. But filling the cavity between the glasses with argon, which is practiced when assembling energy-saving double-glazed windows, can reduce heat loss due to convection by 10-12%. The effect is associated with the higher viscosity of argon compared to air, as well as its lower thermal conductivity.

Argon significantly reduces heat loss due to convection.

Films

1. How effective is energy-saving window film??

High-quality film from reputable manufacturers (for example, Nanofilm) truly provides filtration in the infrared part of the spectrum and has an efficiency approaching that of i-glass. At the same time, it practically does not darken the room.

Structure of energy-saving film Nanofilm.

In addition to energy-saving, there are mirror and color light-protective films. They are useful on the south side of the house to protect against heating of the room in sunny weather and from excess light.

1. How to properly stick such a film with your own hands?

To apply the film, I strongly advise you to remove the glass unit from the frame. There are two reasons for this:

• When cutting it along the contour of a double-glazed window installed in the frame, it is very easy to damage the rubber seal;
• The inevitable gaps around the edges will look untidy and collect dirt.

To remove a glass unit from the frame, you need:

• Pry the middle of one of the beads (the longer one) with a knife blade or a thin steel spatula and pull it out of the frame. Don’t be afraid of the bead bending, it won’t break;
• Repeat the operation with the remaining glazing beads one by one. The last one to be removed is the top one: it will hold the glass unit in the frame until the last moment.

Dismantling double-glazed windows begins with removing the glazing beads.

The released glass unit is placed on a table covered with a cloth and thoroughly washed to remove any dirt - first with water and any detergent, then with a glass cleaner.

By the time the film is applied, the glass should be clean, transparent and dry.

The film together with the base (the so-called liner) is cut to the size of the glass unit using ordinary scissors. You cannot cut the film after sticking it with a stationery knife. This is simpler, but there is a high risk of breaking the seal of the double-glazed window around the perimeter of the glass.

Then the glass lying on the table is generously moistened with soapy water. This will prevent the formation of air bubbles under the film.

The next stage: the film is peeled off from the liner (it’s best to do this together), after which its adhesive surface is also moistened with soapy water. Then the film is placed with the adhesive side on the glass. All that remains is to drive the water out from under it; this is done by sliding movements of a dry cloth or plastic card from the center to the edges.

If there are still bubbles of water under the film, don't worry about it. It will quickly evaporate.

All that remains is to install the double-glazed window. It is displayed on plastic spacers with a small gap between the bottom edge and the frame; then beads are installed and driven into the frame one by one, starting from the top (with a rubber mallet or a hammer through a block).

The most convenient way to hammer in the bead is with a rubber mallet.

The last bead is pressed into the frame along the edges and hammered in the middle.

Energy-saving window film is glued to the left (blind) sash.

And here is the same window, shot through an infrared filter. The result is obvious: the left valve is opaque.

Technologies

1. What technology is used to produce energy-saving glass??

Until the 1990s, the only technology available was the so-called hard coating (K-glass). It is produced by applying a layer of metal oxides to the hot surface of a glass plate.

During pyrolysis (high temperature chemical reaction) a layer of InSnO2 (a compound of indium, tin and oxygen) is formed on the surface. The main feature of K-glass is the high mechanical strength of the spraying (which is why, in fact, it is called hard).

At the turn of the century, first abroad and then in Russia, i-glass with soft coating became widespread. It is multi-layered; the main components are silver and titanium oxide. The coating is applied in a vacuum by cathode sputtering: metals are deposited on the surface of the glass under the influence of an electromagnetic field.

The advantages of i-glass compared to older technology are greater light transmittance in the visible part of the spectrum (90-92 percent versus 70) and lower permeability to infrared rays.

K-glass transmits only about 70 percent of the light in the visible spectrum.

Currently, K-glass accounts for no more than 10% of market sales. The bulk of the market has been successfully captured by more advanced technology.

1. The coating is applied over the entire glass area?

Initially, yes. But the 10 mm edge along the entire perimeter of the i-glass is cleared of spray when assembling the glass into a double-glazed window. This is necessary in order to ensure adhesion of the sealant. K-glass does not require surgery: its spraying has sufficient strength and adhesive properties.

When assembling a double-glazed window, the edges are cleaned of i-spraying.

1. How long can energy-saving glass be stored before being assembled into a double-glazed unit??

With hard coating - indefinitely, with soft coating - no more than 3 months.

What else affects the energy efficiency of windows?

The energy efficiency of windows depends not only on the type of heat-saving layer, the injection of inert gas and the number of chambers in the double-glazed window. It is directly influenced by profiles, fittings and installation quality. If you don’t take at least one of the points seriously, the windows will retain heat worse.

PVC profiles

The stability of the shapes of window structures and their tightness depend on the choice of these elements. Also, they should not serve as cold bridges, causing a decrease in temperature in the interior and the formation of condensation. To do this, high-quality profiles must have:

• thickness of external and internal walls corresponding to GOST;
• reinforcing liners made of steel;
• smooth surface without defects or yellow spots.

If PVC profiles do not meet the listed criteria, then purchasing energy-efficient double-glazed windows makes no sense. Due to the low quality of plastic and the lack of reinforcement in winter, the structure of the frames and sashes is deformed, and the windows become depressurized.

Fittings and sealing contours

These elements of window structures also provide airtightness. The tight fit of the active sashes to the frame structure will depend on their quality, reliability and functionality. As a result, it is recommended:

1. Choose two-chamber silicone seals to complete the windows and care for them regularly - wipe and lubricate with glycerin every 6 months.

1. Order the integration of microlifts that prevent premature wear of fittings.

1. Ask the manufacturer to use hidden hinges for hanging the sashes, which have a higher level of tightness.

1. Additionally, install micro-slit ventilation devices or supply ventilation valves. This is necessary to reduce heat loss in winter when ventilating rooms.

All these measures are best taken at the stage of ordering windows. Such timely actions will help reduce heat loss by approximately 3-5%.

Installation

Energy-efficient windows made of plastic, wood or aluminum will automatically lose all their heat-saving qualities if the installation is not carried out in accordance with GOST. Ignoring this recommendation entails depressurization of structures around the perimeter of the frames. Other unpleasant problems are also possible - deformation of the window frame, regular fogging of windows due to poor ventilation and the appearance of mold. Buyers are advised to independently familiarize themselves with the list of standards that are displayed in GOST 30971-2012. If the installation was carried out incorrectly and problems arose during the operation of the windows, the client has the right to demand that the deficiencies be corrected. In this case, all responsibility rests with the company that performed the poor-quality installation. When ordering plastic energy-saving windows, the PVC profile can be selected in such a way as to achieve visual similarity with products made from natural wood. This can be done using lamination technology.