What affects the light transmittance of windows and how to increase it

Over the past decades, tinting auto glass in cars has been the subject of serious controversy and frequent changes in Russian legislation, as well as one of the most “popular” traffic violations, for which traffic police inspectors are often fined.

Over the past 5-6 years, the country has already formed a whole legislative package on tinting car windows, on the basis of which employees of the Traffic Inspectorate regulate the rules, requirements, tolerances and restrictions for the level of light transmission of car windows. What are we talking about, and how to understand the rules of auto-tinting?

Comparison of double-glazed windows by light transmission

Sunlight energizes you for great things or simply gives you a good mood. For free. Light enters our apartments through the windows. The mood and well-being for many years depends on which windows we choose. Therefore, if you want more positive things, add maximum light to your window requirements. Technical information: a double-glazed window is not the entire window, it is only its glass part, occupying 70-80% of the structure’s area. The basic principles of gaining light due to double-glazed windows are as follows:

1. The higher the grade of glass, the more light
2. The thinner the glass, the more light
3. The less glass in a double-glazed window, the more light
4. The fewer bells and whistles in the glass (energy-saving, tinted, triplex, etc.) - the more light

Operating instructions for taumeter

We will describe the instructions for the most popular device among police officers - “Blik-N”. If measurements are made in the field, it is attached to a strap that is worn around the neck.

To take measurements, you need to connect the device cord to the car's cigarette lighter, which has a 12V power supply. Next, the taumeter warms up for several minutes. If the device is moved from indoors to fresh air or vice versa, the inspector must make sure that the glass on the head of the device has not fogged up or frozen.

Brand of glass and light

Glass, in accordance with its optical distortions and standardized defects, is divided into grades M0-M7.

GOST 111-2001 Sheet glass, clause 5.1.1, Table 4 Defects and optical distortions affect light transmission. Glass in windows can be used from M0 to M7. However, the recommended glass from the point of view of a minimum of defects is M0 (which is rarely recycled) and M1 (which can be found much more often).

Who and when can check the technical condition of the car?

Tinting that is contrary to the Regulations is the operation of a vehicle in violation of the established rules. Traffic police officers have the right to monitor the technical condition of vehicles, preventing the operation of vehicles with violations.

The powers of the State Traffic Safety Inspectorate regarding monitoring the technical condition of vehicles participating in road traffic are assigned to:

• In the Code of Administrative Offenses of the Russian Federation, which stipulates offenses related to the technical malfunction of a vehicle, the traffic police are indicated as officials authorized to identify these violations and draw up material about violations (Article 23.3 and Part 2 of Article 28.3 of the Code of Administrative Offenses of the Russian Federation);
• In paragraph 31 of the Administrative Regulations.
• In paragraph 111 of the same regulations, which provides the grounds for checking the technical condition of the car.

In fact, the authority of the traffic police when checking the light transmission of tinting in this part is not in doubt. The previously valid order of the Ministry of Internal Affairs No. 1240 provided for the conditions for monitoring the technical condition. In particular, it indicated the possibility of carrying out such control exclusively at stationary posts or specialized inspection stations, however, there are no such restrictions in the current Administrative Regulations.

The thinner the glass, the more light

One of the most important characteristics of glass is the coefficient of directional light transmittance*. The higher the value of this coefficient, the greater the degree of transparency the glass has and the lower its color shade. As thickness increases, the directional transmittance of light decreases, and the greenish or bluish tint of the glass becomes more noticeable. Table 1 Glass thickness and amount of light**

* The coefficient of directional transmission of light is the ratio of the value of the light flux normally passing through the sample to the value of the light flux normally incident on the sample (GOST 26302-93 Glass. Methods for determining the coefficients of directional transmittance and reflection of light, clause 3). **GOST 111-2001 “Sheet glass for construction purposes”, Table 6

The typical thickness of glass used in modern windows is 4 mm. Thicker glass (5 or 6 mm) is used if they want to increase noise protection or the glass unit has a large area (more than 2-2.5 m²), so that the glass unit does not collapse/there is no lens effect (sticking of glass). The thickness of the glass is also related to the maximum wind load that the product must withstand.

Glass with a thickness of 3 mm or less is usually not used for the production of double-glazed windows, due to the lower strength stability of the structure.*** The risk of destruction of a double-glazed window is greater if the glass in it is 3 rather than 4 mm.

***The exception is triplex. These are 2 glasses glued together using a special film or resin.

Rules for window tinting

In order to avoid being brought to administrative liability, you must strictly comply with the requirements for installing a tinting coating. The only legal requirement is throughput, but even this is not always easy to fulfill if tinting occurs in a garage and with unknown materials.

IMPORTANT !!! In addition to the throughput requirements established in GOST, the technical regulations contain an indication that mirror tinting is prohibited. Unlike a regular one, a mirror one does not simply prevent light from entering the cabin, it reflects it back. Such phenomena are extremely dangerous on the roads due to the possibility of blinding another driver. For this reason, it is recommended to refrain from purchasing metallized film with coefficients of more than 50%.

Most car owners perform tinting using regular film, which can be purchased at any store. However, when saving money and purchasing film from an unknown manufacturer, it is extremely difficult to independently determine the level of throughput. This can only be done using a special device, which not everyone has. In this regard, it is recommended not to purchase a product from an unknown manufacturer, or to carry out installation by a special service.

If there are no doubts about tinting, you can carry out the entire procedure yourself, since the law does not provide for any restrictions. Drivers should be aware that applying more than one layer of sticker is highly undesirable, due to a significant reduction in visibility.

The less glass in a double-glazed window, the more light

Table 2 Number of glasses and light****

****GOST 24 866-99 Double-glazed windows for construction purposes, clause 4.1.7, Table 4

In a single-chamber double-glazed window there are 2 glasses, which means the amount of light from the total luminous flux will pass through such a structure 80%. If we replace the double-glazed window with a double-chamber one, i.e. of three glasses – the light will decrease by 8%. Please note that the indicators “Heat transfer resistance” (the higher, the warmer the window) and “Sound insulation” (the higher, the quieter) for a double-chamber double-glazed window are higher by 27 and 7%, respectively. It is not recommended to install windows with standard single-chamber double-glazed windows (aluminum spacers, ordinary glass) in heated rooms, such as apartments, school classrooms, etc.

The fewer bells and whistles in the glass (energy-saving, tinted, triplex, etc.) - the more light

Table 3 Glass shutters and light****

If one glass in a double-glazed window is energy-saving, then there will be less light by 5% if the double-glazed window is 2 glasses (single-chamber) and by 7% if the double-glazed window is 3 glasses (double-chamber).

At the same time, double-glazed windows with energy-saving glass are 60-80% warmer than standard ones (calculated by a simple proportion according to Table 3).

Those. in this case, the benefit from energy saving is much greater than the benefit from light.

Table 4 Type of glass unit and light*****

***** GOST 24 866-99 Double-glazed windows for construction purposes, Appendix A, Table A1

Source: www.wikipro.ru

Weather

Tinting is checked only under certain weather conditions:

• Atmospheric pressure should be within 760 mmHg (+/-30).
• Permissible air humidity is 60% (+/-15).
• The air temperature should vary between 20-25 degrees. Some taumeters can also be used at higher temperatures.
• In winter, air temperatures should not be lower than -10 degrees.

Tinting is not measured in rain or fog. Many people are interested in the question of whether it is possible to check the tint at night. There are no restrictions regarding the time frame - measurements can be taken even late at night.

Light transmission coefficient of double-glazed windows

GLUED GLASS UNITS FOR CONSTRUCTION PURPOSE

OKS 91.060.50* OKSTU 5913 _______________ * In the index “National Standards” 2013 OKS 81.040.20; 91.060.50, 13.200. – Note from the database manufacturer.

Date of introduction 2001-01-01

1 DEVELOPED by JSC Institute of Glass, JSC TsNIIPromzdaniy, Department of Standardization, Technical Standards and Certification of the Gosstroy of Russia with the participation of Glastechniche Industrie Peter Lisec GmbH and the State Institution Federal Scientific and Technical Center for Certification in Construction

INTRODUCED by the State Construction Committee of Russia

2 ADOPTED by the Interstate Scientific and Technical Commission for Technical Standardization and Certification in Construction (INTKS) on December 2, 1999.

Voted for acceptance

Name of the state construction management body

Ministry of Urban Development of the Republic of Armenia

Committee for Construction Affairs of the Ministry of Energy, Industry and Trade of the Republic of Kazakhstan

State Inspectorate for Architecture and Construction under the Government of the Kyrgyz Republic

Ministry of Territorial Development, Construction and Communal Services of the Republic of Moldova

Committee for Architecture and Construction of the Republic of Tajikistan

State Committee for Construction, Architecture and Housing Policy of Uzbekistan

State Committee for Construction, Architecture and Housing Policy of Ukraine

4 ENTERED INTO EFFECT on January 1, 2001 as a state standard of the Russian Federation by Decree of the State Construction Committee of Russia dated May 6, 2000 N 39.

Amendments have been made, published in BLS N 2, 2002, Information Bulletin on normative, methodological and standard design documentation N 4-2004 (BLS N 1, 2004, IUS N 3-2004).

Amendments made by the database manufacturer

What are the requirements for a taumeter?

To measure tint according to GOST, you need to check the taumeter on time. Certification is carried out by the commission on measuring devices. There are some rules that determine the state of the taumeter:

• The certification commission checks the taumeter once every 12 months.
• The person responsible for the inspection puts an individual seal on it and issues a certificate.
• If there are no identification marks on the taumeter, the readings from the device can be considered unreliable. Such results cannot be included in regulations and a fine cannot be issued for them.
• The supply voltage range should be from 11.4 to 12.6 V.
• The certificate can be kept in the traffic police department, and a plate containing the verification date must be attached to the device.

GOST light transmission of double-glazed windows

Sunlight contains ultraviolet radiation, without which a person cannot live. In large doses it is harmful, but you can’t live without it.

Sunlight contains ultraviolet radiation, without which a person cannot live. In large doses it is harmful, but you can’t live without it. This is precisely the argument put forward by opponents of plastic windows, arguing that double-glazed windows do not transmit ultraviolet radiation, and this negatively affects people and plants. Most often, special energy-saving double-glazed windows are subject to such doubts. This type of glass appeared not so long ago, and according to the technology, this requires special equipment. By the way, these are the windows installed in most European countries.

Do I need to go to a stationary traffic police post to take measurements?

If a police officer stopped a driver at a traffic police post and asked him to undergo a check for the light transmittance of car windows, the motorist has the right to refuse to do this, even if the windows of his vehicle are completely tinted.

In this case, the inspector may suggest driving to a stationary post in order to comply with all the rules for measuring tint. Even in this case, the driver may refuse. To force a motorist to go to the inspection point, a police officer must carry out administrative detention. Is this legal?

No, it's not legal. The Code of Contraventions states that it is possible to restrict the freedom of a motorist or any other person only in situations where it is necessary to promptly consider the case of an offense. In this case, detention cannot be used to detect an offense. You can detain a car only if a violation has already been detected, but not before it.

Sunlight standards

Windows that transmit ultraviolet light are installed taking into account a number of requirements, without which installation is impossible. This is a certain light transmittance that provides natural light. There are also standards for ultraviolet transmission; it should also not be less than established sanitary standards.

The comparison table shows which GOST light transmission is established for each type of double-glazed window.

Thus, the average value for a single-chamber package should be no less than 75%, and for a two-chamber package - no less than 72%. Energy-saving glass also complies with international standards, so the fears of fans of sunlight are often unfounded and are not based on knowledge of the manufacture of modern double-glazed windows and sanitary standards.

Ultraviolet radiation, like sunlight, has a beneficial effect on humans, increases immunity, reduces the risk of infections and allergies, and normalizes metabolic processes in the body. When choosing between a single-chamber and a double-chamber package, you don’t have to focus on light transmittance, since it is within normal limits, and increasing the ultraviolet dose, on the contrary, can be harmful. The difference will be that the weight of the two cameras is much greater, and, accordingly, the entire structure will be heavier. Such windows require special fittings with a high degree of strength and reliability. But installing such windows that transmit ultraviolet radiation in the required amount will be much more profitable than choosing wooden frames with ordinary glass.

Films Chameleon

Chameleon has become a popular trend in athermal films. This coating not only has all the useful heat-protective properties, but also has a rich and original color. As a result, the car windshield takes on an unusual shade that shimmers in the sun, similar to the tinting of a business class vehicle. Such films are distinguished by their impeccable quality and high service life.

Chameleon is an excellent design solution for changing the appearance of a car. In the manufacture of this material, a unique technology for applying various metals using magnetron sputtering is used. The result is a coating consisting of almost 20 layers that provide the required protective properties and an eye-catching color effect.

Thanks to the manufacturing technology of Chameleon film:

• does not fade from exposure to direct sunlight;
• provides light transmission in the range from 83 to 90%;
• does not differ at all from factory-made glass for business and premium class cars.

In the sun, such an athermal coating, which initially has a purple tint, shimmers very beautifully with all sorts of delicate colors, which is why it got its name “Chameleon”. When purchasing and installing a coating, special attention should be paid to its throughput. If the Chameleon has it equal to 83%, and the windshield has 90%, then the result will be a maximum permissible figure of 75%. Lower rates will lead to violation of traffic rules and GOST.

Myths about ultraviolet

There can be too much sunlight; this is due to old windows, which can only block part of the radiation. That is why modern manufacturers began to produce double-glazed windows with special protection. Studies have been conducted in Europe that have shown that triplex glass is the best way to protect from a heavy dose of radiation. Companies that produce double-glazed windows provide protection from ultraviolet radiation even in the window profile, which contains special substances that prevent the destructive power of these waves. Such components are called stabilizers. You can find out whether they are contained in a double-glazed window and what quality they are after several years of operation. The trick is that low-quality stabilizers deteriorate in the sun and this causes the profile to turn yellow.

Source: www.oknarosta.ru

How to check glass for light transmittance

The rules for measuring tint provide the following algorithm of actions:

• The inspector measures the current air temperature and humidity, and atmospheric pressure.
• The glass must be wiped until clean and dry.
• You can measure if the device has an error of 2% or less.
• The inspector presents the driver with a certificate or shows a sign containing the date of inspection of the tuamere, a protocol, or a personal document according to which he has the right to carry out measurements.

What affects the light transmittance of windows and how to increase it

Windows in openings with the same area can let in different amounts of light. This parameter is directly influenced by the brand of glass and a number of secondary factors. Much depends on the type and dimensions of the profile system, the model of the glass unit, the presence of reinforcement or sun protection films. However, the determining factor is the light transmittance of the glass, which can differ significantly for products of different brands and configurations.

How to determine the light transmission of film

You can find out this parameter by the marking of the film. The number on the packaging gives an accurate indicator of possible visibility. Let's see how standard films affect the final result:

Scheme of blind tinting “in a circle”«:

• rear (including door windows) - 5%;
• side front doors - 15%;
• windshield - 35%.

In practice, the part of the cabin behind the front seats is completely invisible. If you look closely, you can see the outlines of those sitting in front. There is no need to talk about compliance with standards with such a scheme.

Partial tinting scheme:

• rear windows - 15%;
• front doors - 15%;
• windshield is not processed.

The driver is provided with satisfactory visibility of the road in front of the car, visibility of the side areas and behind the vehicle is reduced. on the windows The requirements are violated on the windows of the front doors.

Rear semicircle pattern:

• the “forehead” and front side windows remain clean;
• The rear door glazing is covered with a film with any light tolerance rating.

This option practically corresponds to GOST.

Video: Tinting car windows according to GOST requirements. What tint is acceptable?

A selection for you!

Download forms and sample documents for motorists to a safe place.

What determines the light transmittance of glass?

Glass is an amorphous material that is produced industrially by supercooling a molten mass, which includes silicate materials - limestone, quartz sand, soda and other substances. It is these components, together with production and processing technologies, that form the overall characteristics of glass, including their light transmittance. Moreover, the amount of light passing through a sheet of glass simultaneously depends on two properties of this material:

• absorption - the components included in the glass partially absorb a certain amount of rays of the visible spectrum;
• reflection – the surface of glass sheets “mirrors” a certain percentage of light.

All rays of the visible spectrum that are not absorbed or reflected pass through the glass. The better the surface is polished and the fewer impurities and cavities inside, the higher its light transmittance.

Also, the degree of light transmission is affected by the thickness of the sheets, since as it increases, the amount of absorbed light also increases.

Fines for tinting a windshield

Previously, as a punishment for the fact that a motorist used tinting that did not meet the requirements of GOST and technical regulations of the vehicle, the license plate number was removed from the car.

The car owner could not drive the car until he paid the fine. Today this preventive measure is not in effect. However, this does not mean that you can not comply with GOST requirements. Fully tinted car windows are allowed only on special vehicles that have the legal right to travel within the territory of the Russian Federation, even with tinting.

In addition, it should be remembered that according to the law, a fine is imposed at certain intervals. For example, if a police officer draws up a report because the tinting does not meet the requirements of GOST, it must be dated. According to the rules, a repeated protocol can be issued only one day after the first one is issued.

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This means that if you are stopped twice by police officers within 24 hours, you can show the previously drawn up report, which indicates the day it was issued. The police do not have the right to impose a second fine or subject the owner of the car to administrative detention (or arrest). This can only be done through the courts.

A fine will be issued even if you have installed removable tinting on the front side windows: double glass or curtains.

What to do if you don't want to be fined? After your car is stopped by police officers to check the tint, you have the right to remove it even in front of a traffic police inspector present. This action will allow you to avoid a fine.

Also, if you notice that a police officer is checking the tint in violation of the requirements, you must inform him about it. In such a situation, you will have the opportunity to prove in court that the test was performed incorrectly and its results are invalid. Then you won't have to pay a fine.

Many motorists are against the new GOST; they demand changes to the requirements for tinting car windows. For example, one of their requirements is to set the permitted degree of light transmittance for the windshield to 60%, and for side car windows to 40%.

Also, many drivers are in favor of allowing mirror tinting. It is impossible to answer unequivocally whether the state will meet them halfway or not. To avoid fines, you must comply with the current requirements of GOST and technical regulations of the CU.

Glass brand

Sheet glass in our country is marked according to GOST 111-90. The following short notations are used to classify it:

• “M” – brand of glass;
• “SVR” – sheets of free sizes that are produced without customer specifications;
• “TR” is glass with rigid dimensions, in the production of which the dimensions provided by the client are strictly adhered to.

Glass marked “M” is used for the production of windows. Depending on the thickness, quality of polishing, amount of impurities and defects, they are assigned a number from 1 to 8. The highest light transmission capacity is for “M1” glass, and the lowest is for “M8”. Traditionally, the brands “M3” and “M4” are usually used for windows.

What to consider when tinting

There are points that will have to be taken into account when styling:

• mirror tinting is absolutely prohibited;
• In addition to maintaining the visibility of the glass, the driver’s color perception should not be distorted. And even without film tricks it worsens in the dark;
• Even new glass does not initially transmit light completely: up to 90-95%. Road dust will further reduce visibility by 5-10%. If “worn-out” glass is installed, then its ability to transmit visible rays is reduced by about 20%. Therefore, even a film that meets the requirements of GOST can fail when meeting an inspector on the road;
• Cars of some foreign brands are already coming off the assembly line with tinted windows. Additional devices will definitely lead to non-compliance with standards.

When a car is purchased second hand, before applying light protection, you should measure how much light the windshield, side and rear windows initially transmit in daytime conditions, as well as at dusk. For a new car, the data can be found in the owner's manual.

Clarified and float glass

Sheets obtained using thermal polishing technology are called float glass. The essence of this technique is that the silicate mass from the smelting furnace is poured into baths filled with tin. When poured over a perfectly flat and smooth metal surface, glass acquires similar characteristics. An absolute minimum of defects and optical distortions ensures virtually unhindered passage of light through such sheets. Thanks to this technology, it became possible not to resort to grinding and polishing glass. Currently, three types of float technology are known - Soviet, English and American. Float glass can be tinted and transparent, and untinted sheets have a light transmission percentage of over 88%, which is an excellent indicator.

Lightened glass (Optiwhite) not only provides the highest possible light transmittance, but also natural color rendition. This effect was achieved through “enlightenment”. This technology allows us to minimize the percentage of iron impurities that give ordinary glass a greenish-turquoise tint and are involved in the reflection and absorption of light. Optiwhite sheets are actively used for glazing shop windows and facades of luxury buildings. Triplex made using Optiwhite glass transmits visible rays significantly better.

Who has the right to measure the light transmittance of glass?

Road Technical Supervision, as well as any other traffic police officer who has a rank, can check the technical condition of a car. Other services do not have the right to check the level of light transmittance of car windows.

The special rank is regulated by the Law “On Police”. This can be absolutely any traffic police officer from junior to senior management.

The rules for measuring tinting imply checking the level of light transmittance of glass at a police control post, as well as at stationary traffic police posts.

Double-glazed windows

Regardless of the materials used to make sashes and frames, almost all modern window designs are made using double-glazed windows. It is these elements that are largely responsible for the light transmittance, which, in turn, depends on what kind of glass was chosen for the double-glazed window:

• triplex;
• lightened;
• regular brands “M(3-4)” and float;
• stained glass;
• energy efficient with ionic layer;
• self-cleaning;
• electrochromic;
• reinforced

All glass, with the exception of the “M(1-4)” grades, thermopolished (float) and lightened sheets, have a reduced light transmittance. This is due to the fact that for their manufacture additional materials were used (polymer films, dyes, metals) that reflect or absorb rays of the visible spectrum.

Single-chamber double-glazed windows transmit more light than double-chambered ones, since their production requires one less sheet of glass.

Responsibility for deviations from standards

Well, there’s so much you can’t read on the Internet. And 5 thousand, and one and a half. Sometimes they write about a “progressive” system of fines for repeated detections of incorrect tinting. However, this information is not true. As of December 2022, administrative responsibility in this part is insignificant:

• The punishment is provided for in Part 31 of Art. 12.5 of the Code of Administrative Offenses of the Russian Federation and amounts to 500 rubles . No options or warnings;
• Any State Traffic Inspectorate employee with a special rank has the right to draw up a protocol and issue a fine at the scene of the accident;
• no additional security measures (removal of license plates or detention of the vehicle) are applied.

But if the driver does not pay the fine within 70 days from the date of entry into force of the AR, he will be held accountable under Art. 20.25 p.1. This is where the fine can be doubled and more. According to the decision of the court that considers such cases, you can be sentenced to 15 days or receive up to 50 hours of compulsory work.

Failure to pay fines within the legal period is an independent type of offense. The same punishment threatens other fines for “delays”. Even if the driver has been punished under 20.25, the obligation to “settle” for the first accident is not removed from him.

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The influence of window frames on the light transmittance of structures

The number of component elements in the frames, which you can learn more about in the article on OknaTrade, and their dimensions have a direct impact on how much light transmittance the windows will have. For narrow profile products with fewer horizontal and vertical imposts, this figure is always higher.

Additionally, the decorative layout prevents the passage of visible rays. That is, if we compare these parameters for a fixed, double-leaf and three-leaf model with a window and decorative elements, then the highest light transmittance will be for a blind window, and the lowest for a three-leaf window with a window and a layout.

Source: www.oknatrade.ru

Become more invisible or is there a GOST after tinting?

The final light transmittance can be calculated by multiplying the initial indicators of glass and film. Let’s say a car repair shop applied a regular 50% film to good glass. We get 0.9 x 0.50 = 0.45.

Thus, applying standard films to the front “semicircle” will definitely make us violators. This is confirmed by traffic police officers.

But if you choose a high-quality thermal film, then the chances of not disturbing it are much greater.

Tinting is a special darkening coating on car windows designed to minimize the entry of light rays and visibility of the car interior.

Thanks to the tinting coating, it will be possible to reduce the light absorption of the glass, and this prevents heating of the interior.

However, excessively tinted vehicle windows directly contradict established laws of the Government of the Russian Federation, which will entail the imposition of a fine.

The law, which changed the standards for the use of tinting coatings for automobile windows, has already been in force in the country since January 1, 2017.

What is the essence of tightening glass tinting rules? What tinting is allowed according to GOST in 2022 and how will this affect ordinary motorists?

Double-glazed windows

The main element of a double-glazed window is glass.

A double-glazed window is a product made of two or more glasses, hermetically connected to each other using a spacer frame, as well as internal and external sealant, forming a closed cavity filled with dried air or inert gases.

Double-glazed windows are the most rational means of increasing the thermal and sound insulation of a room when filling the light openings of windows and doors with it.

Due to their high heat and sound insulation properties, double-glazed windows are widely used as an important building element; their production began to develop back in the 30s. The decisive role was played by the fact that dry air is a good heat insulator, its thermal conductivity is almost 27 times lower than glass. Heat loss in a double-glazed window made of two transparent glasses is distributed as follows: about 2/3 occurs due to radiation and 1/3 through heat transfer and convection combined.

The feasibility of using double-glazed windows to fill light openings is determined by the presence of a sealed air gap filled with dehydrated air or inert gas.

Between the glasses there is a thin-walled aluminum frame with perforations, filled with a so-called molecular sieve, which absorbs residual moisture and protects the glasses from fogging, as well as several lines of durable seals. Not only dried air can be used as filling, but also inert gas argon, which improves the heat-shielding properties of the glass unit.

The finished double-glazed window is filled around the entire perimeter with two-component thiokol mastic, which prevents moisture or dust from getting inside.

The tightness of the double-glazed window is ensured by two sealants (sealants): the first is applied to the gap between the frame and the glass, ensuring their tight fit to each other, the second is a connecting edge that is poured from the outside. For the production of double-glazed windows, sealants of the brand of the recognized world leader - “Kommerling” are used.

Thanks to the tightness, moisture and dust do not enter the air gap, and the illumination of the premises does not deteriorate.

A double-glazed window performs two main functions: heat preservation and sound insulation. For our climate zone, double-chamber double-glazed windows with energy-saving glass (k - glass or i - glass) are optimal. To reduce heat losses, you can also fill the space between the glasses with inert gases or increase the distance between the glasses.

For the manufacture of double-glazed windows, glass of various thicknesses is used - 4, 5 or 6 (mm).

Double-glazed windows can be single-chamber - a system consisting of two glasses at a fixed distance (the usual standard is 12 and 16 (mm)) and double-chamber - consisting of three glasses.

Double-glazed windows have different thicknesses: 24 (mm), 28 (mm), 30 (mm), 32 (mm), 42 (mm). The expression “formula of a single-chamber double-glazed window of 24 (mm): 4 – 16 – 4” means that two glasses 4 (mm) thick are connected into a “sandwich” with a distance of 16 (mm) between them.

Double-glazed windows are used to improve thermal performance and reduce noise levels. In order for noise to be dampened most effectively, the distances between the glasses in one block of double-glazed windows must be different.

Energy-saving glass can be installed in double-glazed windows - glass with a special coating that reflects infrared rays. Double-glazed windows can be assembled from safety laminated glass using protective films; reinforced glass, colored or mosaic glass.

In the manufacture of double-glazed windows, different types of glass can be used - tinted solar control, colored decorative, tempered, especially durable. Popular are double-glazed plastic windows with energy-saving glass that has the ability to reflect thermal radiation. Low-emissivity glass has a high heat transfer resistance coefficient of 0.52 m20C/W and in the cold season does not allow heat from the apartment to escape into the street, and in the summer, on the contrary, does not allow heat from outside to enter the home.

There is low-emissivity k-glass with a heat-reflecting coating and glass with a soft, effective, expensive coating but not very durable. To protect it from damage, soft glass is placed with a coating inside the glass unit. Hard coating is resistant to mechanical stress and is much cheaper than soft coating. A single-chamber package with k-glass retains heat like a two-chamber package made of ordinary M-1 glass.

All our double-glazed windows comply with the requirements of GOST 24866 - 99 “Glued double-glazed windows for construction purposes”.

The guaranteed service life of the glass unit is at least 15 years.

• SPO – single-chamber double-glazed window
• SPD – double-glazed window

Glass marking of double glazed unit

• Sheet (GOST 111) – “M1”, “M2”, “M4”, “M7”
• Energy-saving with hard coating – “K” “K-glass”
• Energy-saving with soft coating – “I” “Low E”

An example of a symbol for a two-chamber double-glazed window, consisting of three sheet glasses 4 (mm) thick, grade “M1”, with a distance between the glasses of 12 (mm), filled with air: SPD 4M1 – 12 – 4M1 – 12 – 4M1

Technical characteristics of glass and double-glazed windows

Characteristics of various types of glass, thickness 4 (mm) of various brands

Characteristics of various types of glass Brand of glass Light transmittance of glass, % Light transmittance of double-layer glazing, % Light transmittance of three-layer glazing, % M1 (GOST 111-90) 88 81.9 73.4 M4 (GOST 111-90) 85 72, 7 62.5 The best tested at the Steklo Research Center 91.5 84.3 78.0 The worst tested at the Steklo Research Center 82.5 68.5 57.1 Requirements for the light transmission of double-glazed windows for general construction purposes GOST 24866-99 – >=80 >=72 Requirements for light transmission of energy-saving double-glazed windows GOST 24866-99 – >=75 >=68

As can be seen from this table, the difference in the light transmittance of sheet glass of the same thickness can reach 9%, with double-layer glazing - 16%, with three-layer glazing - 21%. As already noted, coatings on glass reduce its light transmittance, therefore, in order to “keep” the overall transmittance of coated glass within acceptable limits and ensure standard glazing transmittances, coatings must be applied to glass with a high transmittance.

Source: www.profti.ru

Bandwidth Measurement

The driver can only be held accountable for failure to comply with established standards. To prove the fact of a violation, it is necessary to make special measurements with instruments. Any words of the inspector about non-compliance without documentary evidence (even if there really is a non-compliance with the norm) have no legal force. It is impossible to hold the driver accountable without carrying out special measurements in accordance with all the rules.

Today, all measurement rules are enshrined in regulations and regulations.

Each inspector is obliged to comply with all requirements of the documents to recognize evidence as valid:

• verification is carried out at special posts where certified equipment is available. The driver has every right to ask for documentation for the device;
• measurements are taken only in dry and clear weather. Air humidity should not exceed 80%;
• the glass should not be dirty or wet;
• the final result is the sum of the arithmetic average of three measurements at different points of the glass;
• measurements are taken only at normal pressure levels;
• the device must be certified, have a seal, and the measurements are made by an employee trained in this.

In practice, it is quite difficult to fulfill all the requirements, so you should pay attention to the main ones: glass contamination, air humidity and the availability of documentation for the device.

Inspectors may take measurements with violations, but then this evidence must be invalidated. To do this, you will need to make a comment in the protocol and subsequently appeal the decision in an administrative or judicial manner.

Terms and Definitions

Low emission coating

Low-emissivity coating: A coating, when applied to glass, the thermal characteristics of the glass are significantly improved (the heat transfer resistance of glazing using glass with a low-emissivity coating increases, and the heat transfer coefficient decreases).

Sun protection coating

Solar control coating: A coating that, when applied to glass, improves the protection of a room from the penetration of excess solar radiation.

Emission factor

Emissivity (corrected emissivity): The ratio of the emissive power of a glass surface to the emissive power of a black body.

Normal emission factor

Normal emissivity (normal emissivity): The ability of glass to reflect normally incident radiation; is calculated as the difference between unity and the reflectance in the direction normal to the glass surface.

Solar factor

Solar factor (total solar energy transmittance coefficient): The ratio of the total solar energy entering the room through a translucent structure to the energy of incident solar radiation. The total solar energy entering the room through a translucent structure is the sum of the energy directly passing through the translucent structure and that part of the energy absorbed by the translucent structure that is transferred into the room.

Directional light transmittance

The coefficient of directional light transmission (equivalent terms: light transmittance, light transmission coefficient), is denoted as τv (LT) - the ratio of the value of the light flux normally passing through the sample to the value of the light flux normally incident on the sample (in the wavelength range of visible light) .

Light reflectance

Light reflection coefficient (equivalent term: coefficient of normal light reflection, light reflectance coefficient) is denoted as ρv (LR) - the ratio of the value of the luminous flux normally reflected from the sample to the value of the luminous flux normally incident on the sample (in the wavelength range of visible light).

Light absorption coefficient

The light absorption coefficient (equivalent term: light absorption coefficient) is denoted as av (LA) - the ratio of the value of the light flux absorbed by the sample to the value of the light flux normally incident on the sample (in the wavelength range of the visible spectrum).

Solar transmittance

The solar energy transmittance coefficient (equivalent term: direct solar energy transmittance coefficient) is denoted as τе (DET) - the ratio of the value of the solar radiation flux normally passing through the sample to the value of the solar radiation flux normally incident on the sample.

Solar reflectance

The solar energy reflectance coefficient is denoted as ρе (ER) - the ratio of the value of the solar radiation flux normally reflected from the sample to the value of the solar radiation flux normally incident on the sample.

Solar absorption coefficient

The solar energy absorption coefficient (equivalent term: energy absorption coefficient) is denoted as ae (EA) - the ratio of the value of the solar radiation flux absorbed by the sample to the value of the solar radiation flux normally incident on the sample.

Shading coefficient

The shading coefficient is designated as SC or G - the shading coefficient is defined as the ratio of the flux of solar radiation passing through a given glass in the wave range from 300 to 2500 nm (2.5 microns) to the flux of solar energy passing through glass 3 mm thick. The shading coefficient shows the proportion of transmission not only of the direct flow of solar energy (near infrared radiation), but also radiation due to energy absorbed in the glass (far infrared radiation).

Heat transfer coefficient

Heat transfer coefficient - denoted as U, characterizes the amount of heat in watts (W) that passes through 1 m2 of a structure with a temperature difference on both sides of one degree on the Kelvin scale (K), unit W/(m2•K).

Heat transfer resistance

Heat transfer resistance is designated as R - the reciprocal of the heat transfer coefficient.

Source: www.salstek.com

Does the visibility of the front windows worsen?

There is a clear opinion on this question, which no one has yet attempted to refute: the windshield should have maximum transparency. Traffic safety depends on how well the driver sees the road and the situations around the car.

You can tint a car with any film: 50, and even 70 percent, the photo of which is given above. However, it must be taken into account that visibility will be significantly reduced, and the car owner will sooner or later be detained by a traffic inspector.

He will issue him a decree and a fine under clause 3 of Art. 12.5 of the Code of Administrative Offenses of the Russian Federation “Driving a vehicle in the presence of a malfunction or a condition that does not allow its use.” As a comparison, you can look at the photo: a car with 70 percent tint and one with 30, according to the American standard.

The difference is quite noticeable, it’s strange why domestic traffic rules, which have recently become more and more similar to American and European ones, do not strive to adopt this standard.