Estimated transmission resistance of pvc entrance doors. Data on the resistance to heat transfer of windows, balcony doors and skylights of various designs. Steel entrance exterior doors

Thermal insulation (thermal protection)

Thermal insulation is one of the main functions of a window, which provides comfortable conditions indoors.
The heat loss of a room is determined by two factors:

• transmission losses, which are made up of heat flows that the room gives off through walls, windows, doors, ceiling and floor.
• ventilation losses, which is understood as the amount of heat required to heat up to room temperature cold air penetrating through window leaks and as a result of ventilation.

In Russia, to assess the heat-shielding characteristics of structures, it is accepted heat transfer resistance R o(m² · °C/W), the reciprocal of the thermal conductivity k, which is accepted in DIN standards.

Thermal conductivity coefficient k characterizes the amount of heat in watts (W) that passes through 1m² of construction with a temperature difference on both sides of one degree on the Kelvin (K) scale, the unit of measurement is W / m² K. The lower the value k, the less heat transfer through the structure, i.e. higher insulating properties.

Unfortunately, a simple recalculation k V R o(k=1/R o) is not quite correct due to the difference in measurement methods in Russia and other countries. However, if the product is certified, then the manufacturer is obliged to provide the customer with an indicator of resistance to heat transfer.

The main factors affecting the value of the reduced heat transfer resistance of the window are:

• window size (including the ratio of the glazing area to the area of ​​the window block);
• cross section of the frame and sash;
• window block material;
• type of glazing (including the width of the distance frame of the double-glazed window, the presence of selective glass and special gas in the double-glazed window);
• number and location of seals in the frame/sash system.

From the value of indicators R o also depends on the surface temperature of the enclosing structure facing the inside of the room. At big difference temperature, heat is radiated towards the cold surface.

Poor heat-shielding properties of windows inevitably lead to the appearance of cold radiation in the area of ​​windows and the possibility of condensation on the windows themselves or in the area of ​​​​their junction with other structures. Moreover, this can occur not only as a result of the low heat transfer resistance of the window structure, but also due to poor sealing of the frame and sash joints.

Heat transfer resistance of enclosing structures is standardized SNiP II-3-79*"Construction Heat Engineering", which is a reissue SNiP II-3-79"Construction Heat Engineering" with amendments approved and put into effect on July 1, 1989 by Decree of the USSR Gosstroy of December 12, 1985 No. 241, Amendment 3, put into effect on September 1, 1995 by Decree of the Ministry of Construction of Russia of August 11, 1995 18-81 and change 4, approved by the Decree of the Gosstroy of Russia of January 19, 1998 18-8 and put into effect on March 1, 1998

In accordance with this document, when designing, the reduced resistance to heat transfer of windows and balcony doors R o should take at least the required values, R o tr(see table 1).

Table 1. Reduced heat transfer resistance of windows and balcony doors

Degree-days of the heating period(GSOP) should be determined by the formula:

GSOP \u003d (t in - t from.per.) · z from.per.

Where
t in- design temperature of internal air, °C (according to GOST 12.1.005-88 and design standards for relevant buildings and structures);
t from.per.- average temperature of the period with average daily air temperature below or equal to 8°C; °C;
z from.trans.- duration of the period with an average daily air temperature below or equal to 8°C, Days (according to SNiP 2.01.01-82"Construction climatology and geophysics").

By SNiP 2.08.01-89* when calculating the enclosing structures of residential buildings, it should be taken: the temperature of the internal air is 18 ° C in areas with the temperature of the coldest five-day period (determined in accordance with SNiP 2.01.01-82) above -31 ° C and 20 ° C at -31 ° C and below; relative humidity air equal to 55%.

Table 2. Outside air temperature(optional, see SNiP 2.01.01-82 in full)

To facilitate the work of designers in SNiP II-3-79*, the appendix also contains a reference table containing the reduced heat transfer resistance of windows, balcony doors and lanterns for various designs. It is necessary to use these data if the values R missing from the standards or specifications on construction. (see note to table 3)

Table 3. Reduced heat transfer resistance of windows, balcony doors and skylights(reference)

In addition to the all-Russian regulatory documents, there are also local ones in which certain requirements for a given region can be tightened.

For example, according to the Moscow city building codes MGSN 2.01-94"Energy supply in buildings. Standards for thermal protection, heat and water supply.", Reduced resistance to heat transfer (Ro) must be at least 0.55 m² °C/W for windows and balcony doors (0.48 m² °C/W is allowed in the case of double-glazed windows with heat-reflecting coatings).

The same document contains other clarifications. To improve the thermal protection of the fillings of light apertures in the cold and transitional periods of the year without increasing the number of glazing layers, it is necessary to provide for the use of glass with a selective coating, placing them on the warm side. All porches of window frames and balcony doors must contain sealing gaskets made of silicone materials or frost-resistant rubber.

Speaking of thermal insulation, it must be remembered that in summer windows should perform the opposite function of winter conditions: to protect the room from penetration solar heat to a cooler area.

It should also be taken into account that blinds, shutters, etc. act as temporary heat shields and significantly reduce heat transfer through windows.

Table 4. Heat transmission coefficients of sun protection devices
(SNiP II-3-79*, Appendix 8)

In one of the previous articles, we discussed composite doors and briefly touched upon blocks with a thermal break. Now we dedicate a separate publication to them, since this is quite interesting products, we can say - already a separate niche in the door industry. Unfortunately, in this segment, not everything is clear, there are achievements, there is a farce. Now our task is to understand the features new technology, to understand where technological "goodies" end, and where marketing games begin.

To understand how thermally separated doors work, and which of them can be considered as such, you will have to delve into the details and even remember a little school physics.

If you are still undecided, check out our offers

1. This is a natural process of striving for balance. It consists in the exchange / transfer of energy between bodies with different temperatures.
2. Interestingly, hotter bodies give off energy to colder ones.
3. Naturally, with such a return, warmer parts cool down.
4. Substances and materials with different intensity transfer heat.
5. The definition of the thermal conductivity coefficient (denoted as c) calculates how much heat will pass through a sample of a given size, at a given temperature, per second. That is, in applied matters, the area and thickness of the part, as well as the characteristics of the substance from which it is made, will be important. Some metrics to illustrate:
   • aluminum - 202 (W/(m*K))
   • steel - 47
   • water - 0.6
   • mineral wool - 0.35
   • air - 0.26

Thermal conductivity in construction and for a metal door in particular

All enclosing building construction transfer heat. Therefore, in our latitudes, there is always heat loss in a dwelling, and heating is necessarily used to replenish them. Windows and doors installed in openings have a disproportionately thinner thickness than walls, which is why there is usually an order of magnitude more heat loss here than through walls. Plus, the increased thermal conductivity of metals.

What problems look like.

Naturally, the doors that are installed at the entrance to the building suffer the most. But not at all, but only if the temperature differs greatly from inside and outside. For example, the common entrance door is always completely cold in winter, there are no particular troubles with steel doors for an apartment, because it is warmer in the entrance than on the street. But the door blocks of cottages work at the temperature limit - they need special protection.

Obviously, in order to exclude or reduce heat transfer, it is necessary to artificially equalize the internal and "outboard" temperatures. In fact, a large air layer is created. Traditionally, there are three ways:

• Allow the door to freeze by installing the second door block from the inside. The heating air does not make its way to the front door, and there is no sharp temperature drop - no condensate.
• They make the door always warm, that is, they build a vestibule outside without heating. It equalizes the temperature on the outer surface of the door, and heating warms up its inner layers.
• Sometimes the organization of an air thermal curtain helps, electric heating linen or underfloor heating near the front door.

Of course, the steel door itself should be insulated as much as possible. This applies to both the cavities of the box and the canvas, and the slopes. In addition to cavities, linings work to resist heat transfer (the thicker and "fluffier" - the better).

Thermal break technology

The eternal dream of the developer to forever and irrevocably defeat heat transfer. The disadvantages are that the most warm materials, as a rule, the most brittle and weakly bearing, due to the fact that the resistance to heat transfer is highly dependent on density. To strengthen porous materials(which contain gases) they need to be combined with stronger layers - this is how sandwiches appear.

However, the door unit is a self-supporting spatial structure that cannot exist without a frame. And then other unpleasant moments appear, which are called "cold bridges". This means that no matter how well the steel front door is insulated, there are elements that pass through the door. These are: the walls of the box, the perimeter of the canvas, stiffeners, locks and hardware - and all this is made of metal.

At one point, manufacturers aluminum structures found a solution to some topical issues. One of the most thermally conductive materials ( aluminum alloys) decided to separate the less thermally conductive material. The multi-chamber profile was “cut” approximately in half and a polymer insert (“thermal bridge”) was made there. So that the bearing capacity would not be particularly affected, a new and rather expensive material was used - polyamide (often in combination with fiberglass).

The main idea of ​​such constructive solutions is to increase the insulating properties, avoiding the creation of additional door blocks and vestibules.

Recently, high-quality entrance doors with thermal breaks assembled from imported profiles have appeared on the market. They are made using a similar technology as the "warm" aluminum systems. Only the bearing profile is created from rolled steel. Of course, there is no extrusion here - everything is done on bending equipment. The profile configuration is very complex; special grooves are made for the installation of a thermal bridge. Everything is arranged in such a way that the polyamide part with an H-shaped section becomes along the line of the canvas and connects both halves of the profile. The assembly of products is carried out by pressure (rolling), the connection of metal and polyamide can be glued.

From such profiles, the power frame of the canvas, racks and lintels of the frame, as well as the threshold are assembled. Naturally, there are some differences in the configuration of the section: the stiffener can be a simple square, and to provide a quarter or an influx of the web on the porch, it is a little more complicated. sheathing power frame produced according to the traditional scheme, only with sheets of metal on both sides. The peephole is often abandoned.

By the way, there is an interesting system when the canvas on polymer harpoons (with elastic seals) is literally completely recruited from a profile with a thermal break. Its walls replace the sheathing sheets.

Naturally, “funny” doors appeared on the market, which mercilessly exploit the concept of a thermal break. At best, some tuning of an ordinary steel door is performed.

1. First of all, manufacturers remove stiffeners. Immediately there are problems with the spatial rigidity of the canvas, resistance to deflection, "spike" opening of the skin, etc. As an exit to metal sheets skins sometimes attach underdeveloped stiffeners. Some of them are fixed on the outer sheet, the other part - on the inner. In order to somehow stabilize the structure, the cavity is filled with foam, which simultaneously performs a shaping function and glues both sheets together. There are models where a metal mesh / grate is inserted into the foam so that an attacker cannot cut a through hole in the canvas.
2. The extreme end faces of the leaf and the box can even have small separating inserts, however, with unknown characteristics. In general, the whole structure is not much different from ordinary Chinese doors. We just have a thin shell, only filled with foam.

Another trick is to take an ordinary door with ribs (given the cunning approach to business - usually low-grade) and insert cotton wool into the canvas and, in addition, a layer, for example, foam. After that, the product is awarded the title of "thermal break sandwich" and it is quickly sold as an innovative model. According to this principle, all steel door blocks can be recorded in this category, because the insulation and decorative trim significantly reduce heat loss.

The required total heat transfer resistance for external doors (except for balcony doors) must be at least 0.6
for the walls of buildings and structures, determined at the calculated winter temperature of the outside air, equal to the average temperature of the coldest five-day period with a security of 0.92.

We accept the actual total resistance to heat transfer of external doors
=
, then the actual heat transfer resistance of the outer doors
, (m 2 С) / W,

, (18)

where t in, t n, n, Δt n, α in is the same as in equation (1).

The heat transfer coefficient of external doors k dv, W / (m 2 С), is calculated according to the equation:

.

Example 6. Thermotechnical calculation of external fences

Initial data.

The building is residential, t в = 20С .

The values ​​of thermal characteristics and coefficients t xp (0.92) = -29С (Appendix A);

α in \u003d 8.7 W / (m 2 С) (table 8); Δt n \u003d 4С (table 6).

Calculation procedure.

Determine the actual heat transfer resistance of the outer door
according to equation (18):

(m 2 С) / W.

The heat transfer coefficient of the outer door k dv is determined by the formula:

W / (m 2 С).

2 Calculation of heat resistance of external fences in the warm period

External fences are tested for heat resistance in areas with an average monthly air temperature in July of 21°C and above. It has been established that fluctuations in the outdoor air temperature A t n, С, occur cyclically, obey the law of a sinusoid (Figure 6) and, in turn, cause fluctuations in the actual temperature on the inner surface of the fence
, which also flow harmonically according to the sinusoid law (Figure 7).

Heat resistance is the property of the fence to maintain a relatively constant temperature on the inner surface τ in, С, with fluctuations in external thermal influences
, С, and provide comfortable conditions in the room. As you move away from the outer surface, the amplitude of temperature fluctuations in the thickness of the fence, A τ , С, decreases mainly in the thickness of the layer closest to the outside air. This layer of thickness δ rk, m, is called the layer of sharp temperature fluctuations A τ , С.

Figure 6 - Fluctuations in heat flows and temperatures on the surface of the fence

Figure 7 - Attenuation of temperature fluctuations in the fence

The heat resistance test is carried out for horizontal (covering) and vertical (wall) fences. First, the permissible (required) amplitude of the temperature fluctuations of the inner surface is set
external fences, taking into account sanitary and hygienic requirements according to the expression:

, (19)

where t nl is the average monthly outdoor air temperature for July (summer month), С, .

These fluctuations are due to fluctuations in the calculated outdoor temperatures.
,С, determined by the formula:

where A t n is the maximum amplitude of daily fluctuations of outdoor air in July, С, ;

ρ is the coefficient of absorption of solar radiation by the material outer surface(table 14);

I max, I cf - respectively, the maximum and average values ​​​​of total solar radiation (direct and diffuse), W / m 3, taken:

a) for external walls - as for vertical surfaces of western orientation;

b) for coatings - as for a horizontal surface;

α n - heat transfer coefficient of the outer surface of the fence under summer conditions, W / (m 2 С), equal to

where υ is the maximum of the average wind speeds for July, but not less than 1 m/s.

Table 14 - Solar radiation absorption coefficient ρ

The magnitude of the actual fluctuations on the inner plane
,С, will depend on the properties of the material, characterized by the values ​​D, S, R, Y, α n and contributing to the attenuation of the amplitude   of temperature fluctuations in the thickness of the fence А t . Attenuation factor determined by the formula:

where D is the thermal inertia of the enclosing structure, determined by the formula ΣD i = ΣR i ·S i ;

e = 2.718 is the base of the natural logarithm;

S 1 , S 2 , ..., S n - calculated coefficients of heat absorption of the material of individual layers of the fence (Appendix A, Table A.3) or Table 4;

α n is the heat transfer coefficient of the outer surface of the fence, W / (m 2 С), is determined by the formula (21);

Y 1 , Y 2 ,…, Y n is the coefficient of heat absorption of the material of the outer surface of the individual layers of the fence, determined by the formulas (23 ÷ 26).

,

where δ i is the thickness of the individual layers of the building envelope, m;

λ i is the coefficient of thermal conductivity of individual layers of the building envelope, W/(m С) (Appendix A, Table A.2).

The heat absorption coefficient of the outer surface Y, W / (m 2 С), of a separate layer depends on the value of its thermal inertia and is determined during the calculation, starting from the first layer from the inner surface of the room to the outer one.

If the first layer has D i ≥1, then the coefficient of heat absorption of the outer surface of the layer Y 1 should be taken

Y 1 = S 1 . (23)

If the first layer has D i< 1, то коэффициент теплоусвоения наружной поверхности слоя следует определить расчетом для всех слоев ограждающей конструкции, начиная с первого слоя:

for the first layer
; (24)

for the second layer
; (25)

for the nth layer
, (26)

where R 1, R 2, ..., R n - thermal resistance of the 1st, 2nd and nth layers of the fence, (m 2 С) / W, determined by the formula
;

α в - heat transfer coefficient of the inner surface of the fence, W / (m 2 С) (table 8);

For known values And
determine the actual amplitude of temperature fluctuations of the inner surface of the building envelope
,C,

. (27)

The enclosing structure will meet the requirements of heat resistance if the condition is met

(28)

In this case, the enclosing structure provides comfortable conditions for the room, protecting it from the effects of external heat fluctuations. If
, then the enclosing structure is non-heat-resistant, then it is necessary to take for the outer layers (closer to the outside air) a material with a high heat absorption coefficient S, W / (m 2 С).

Example 7. Calculation of the thermal resistance of an external fence

Initial data.

Enclosing structure, consisting of three layers: cement-sand mortar plaster with bulk density γ 1 = 1800 kg / m 3, thickness δ 1 = 0.04 m, λ 1 = 0.76 W / (m С); a layer of insulation made of ordinary clay bricks γ 2 = 1800 kg / m 3, thickness δ 2 = 0.510 m, λ 2 = 0.76 W / (m С); facing silicate brickγ 3 \u003d 1800 kg / m 3, thickness δ 3 \u003d 0.125 m, λ 3 \u003d 0.76 W / (m С).

Construction area - Penza.

Estimated temperature of internal air t in = 18 С .

The humidity regime of the room is normal.

Operating condition a.

Estimated values ​​of thermal characteristics and coefficients in the formulas:

t nl \u003d 19.8С;

R 1 \u003d 0.04 / 0.76 \u003d 0.05 (m 2 ° C) / W;

R 2 \u003d 0.51 / 0.7 \u003d 0.73 (m 2 ° C) / W;

R 3 \u003d 0.125 / 0.76 \u003d 0.16 (m 2 ° C) / W;

S 1 \u003d 9.60 W / (m 2 ° C); S 2 \u003d 9.20 W / (m 2 ° C);

S 3 \u003d 9.77 W / (m 2 ° C); (Appendix A, Table A.2);

V \u003d 3.9 m / s;

And t n \u003d 18.4 С;

I max \u003d 607 W / m 2,, I cf \u003d 174 W / m 2;

ρ= 0.6 (table 14);

D = R i S i = 0.05 9.6 + 0.73 9.20 + 0.16 9.77 = 8.75;

α in \u003d 8.7 W / (m 2 ° C) (table 8),

Calculation procedure.

1. Determine the permissible amplitude of fluctuations in the temperature of the inner surface
external fence according to equation (19):

2. We calculate the calculated amplitude of fluctuations in the outdoor temperature
by formula (20):

where α n is determined by equation (21):

W / (m 2 С).

3. Depending on the thermal inertia of the building envelope D i = R i S i = 0.05 9.6 = 0.48<1, находим коэффициент теплоусвоения наружной поверхности для каждого слоя по формулам  (24 – 26):

W / (m 2 ° C).

W / (m 2 ° C).

W / (m 2 ° C).

4. We determine the attenuation coefficient of the calculated amplitude of the oscillations of the outside air V in the thickness of the fence according to the formula (22):

5. We calculate the actual amplitude of temperature fluctuations of the inner surface of the building envelope
, С.

If the condition, formula (28), is met, the design meets the requirements for thermal stability.

According to table A11, we determine the thermal resistance of external and internal doors: R nd \u003d 0.21 (m 2 0 C) / W, therefore, we accept double outer doors; R vd1 \u003d 0.34 (m 2 0 C) / W, R vd2 \u003d 0.27 (m 2 0 C) / W.

Then, using formula (6), we determine the heat transfer coefficient of external and internal doors:

W / m 2 about C

W / m 2 about C

2 Calculation of heat losses

Heat losses are conditionally divided into basic and additional.

Heat losses through the internal enclosing structures between the premises are calculated if the temperature difference on both sides is >3 0 С.

The main heat losses of the premises, W, are determined by the formula:

where F is the estimated area of ​​\u200b\u200bthe fence, m 2.

Heat losses, according to formula (9), are rounded up to 10 W. The temperature t in the corner rooms is taken 2 0 C higher than the standard. We calculate heat losses for external walls (NS) and internal walls (VS), partitions (Pr), floors above the basement (PL), triple windows (TO), double external doors (DD), internal doors (DV), attic floors(PT).

When calculating heat losses through the floors above the basement, the outside air temperature t n is taken to be the temperature of the coldest five-day period with a security of 0.92.

Additional heat losses include heat losses that depend on the orientation of the premises in relation to the cardinal points, on wind blowing, on the design of external doors, etc.

The addition to the orientation of the enclosing structures along the cardinal points is taken in the amount of 10% of the main heat losses if the fence is facing east (E), north (N), northeast (NE) and northwest (NW) and 5% - if west (W) and southeast (SE). Additive for heating the cold air rushing in through the outer doors at the height of the building H, m, we take 0.27N from the main heat losses outer wall.

Heat consumption for heating the supply ventilation air, W, is determined by the formula:

where L p - supply air consumption, m 3 / h, for living rooms we accept 3m 3 / h per 1m 2 of living quarters and kitchen area;

 n - the density of the outside air, equal to 1.43 kg / m 3;

c - specific heat capacity, equal to 1 kJ / (kg 0 С).

Household heat releases supplement the heat transfer of heating devices and are calculated by the formula:

, (11)

where F p is the floor area of ​​the heated room, m 2.

The total (total) heat loss of the building Q floor is defined as the sum of the heat loss of all rooms, including staircases.

Then we calculate the specific thermal characteristic of the building, W / (m 3 0 C), according to the formula:

, (13)

where  is a coefficient that takes into account the influence of local climatic conditions (for Belarus
);

V zd - the volume of the building, taken according to the external measurement, m 3.

Room 101 - kitchen; t in \u003d 17 + 2 0 C.

We calculate the heat loss through the outer wall with a northwest orientation (C):

outer wall area F = 12.3 m 2;

temperature difference t= 41 0 C;

coefficient taking into account the position of the outer surface of the building envelope in relation to the outside air, n=1;

heat transfer coefficient taking into account window openings k \u003d 1.5 W / (m 2 0 C).

The main heat losses of the premises, W, are determined by the formula (9):

Additional heat loss for orientation is 10% of Qbase and is equal to:

Tue

Heat consumption for heating the supply ventilation air, W, is determined by the formula (10):

Household heat emissions were determined by the formula (11):

Heat costs for heating the supply ventilation air Q veins and household heat emissions Q household remain the same.

For triple glazing: F=1.99 m 2 , t=44 0 С, n=1, heat transfer coefficient K=1.82W/m 2 0 С, it follows that the main heat loss of the window Q main = 175 W, and additional Q ext \u003d 15.9 W. The heat loss of the outer wall (B) Q main \u003d 474.4 W, and the additional Q ext \u003d 47.7 W. The heat loss of the floor is: Q pl. \u003d 149 W.

We sum up the obtained values ​​of Q i and find the total heat loss for this room: Q \u003d 1710 W. Similarly, we find heat losses for other rooms. The results of the calculation are entered in table 2.1.

Continuation of table 2.1

Continuation of table 2.1

Continuation of table 2.1

After the calculation, it is necessary to calculate the specific thermal characteristic of the building:

,

where α-coefficient, taking into account the influence of local climatic conditions (for Belarus - α≈1.06);

V zd - the volume of the building, taken according to the external measurement, m 3

The resulting specific thermal characteristic is compared by the formula:

,

where H is the height of the calculated building.

If the calculated value of the thermal characteristic deviates by more than 20% compared to the standard value, it is necessary to find out the reasons for this deviation.

,

Because <we assume that our calculations are correct.

Changes to the Federal Law "On Technical Regulation", which allowed the sale in the territory of the Russian Federation of products certified for compliance with the norms and requirements of foreign regulatory legal acts, greatly facilitated the activities of importing companies and retail chains, but by no means the choice of metal doors by Russians. Even with European EN, international ISO and the German DIN standards most commonly used in Russia, it is quite difficult to get acquainted for free, and with the regulatory legal acts of the USA (ANSI), Japan (JISC) or Israel (SII) and China (GB / T), from where a large share of imported metal doors is supplied to our country - it is simply unrealistic for the vast majority of our compatriots.

If you are still undecided, check out our offers

As a result, the risks of buying metal doors that do not meet the very concept of a protective steel door with their performance characteristics are very high. Moreover, advertising labels (“elite”, “prestigious”, “safe”, “armored” metal doors) everywhere “hung” on steel door blocks by selling companies do not in the vast majority of cases correspond to the meaning put into these symbols. So, “elite” metal doors with visually good cladding with wooden linings can have a honeycomb filling of the canvas with cardboard, which makes them an effective heat exchanger in winter, and the hall or corridor behind the entrance doors according to the temperature regime - an internal refrigerator chamber. “Armored” metal doors - a sheathing metal sheet of a leaf with a thickness of 0.6-0.8 mm, which is opened with an ordinary can opener, and the leafs of “safe” metal doors with a good set of insanely expensive locks can be removed from the door frame or together with the box from the opening using a mount and a nail puller or kicked out.

A higher probability of getting an entrance door with good operational properties is to buy metal doors certified for compliance with the norms and requirements of Russian standards, but you need to know at least the basic normalized parameters that determine the level of quality and operational suitability metal door. The basic standard that determines the design and main operational properties of a metal door in Russia is GOST 31173-2003 “Steel door blocks”, and the level of protection of locking mechanisms is GOST 5089-2003 “Locks and latches for doors. Specifications".

Fireproof metal doors in terms of fire resistance, smoke and gas impermeability, but not protective properties, are regulated by GOST R 53307-2009 “Building structures. Fire doors and gates. Fire resistance test method”, and bulletproof and explosion-proof metal doors - by a number of provisions of GOST R 51113-97 “Bank protective equipment. Burglary resistance requirements and test methods”.

Frames of metal door leafs are made of rolled products in accordance with GOST 1050-88 “Calibrated rolled products with special surface finish from high-quality carbon structural steel”, sheet metal is used for sheathing in accordance with GOST 16523-97 “Thin-sheet rolled products from carbon steel of high quality and ordinary quality of general purpose" or GOST 16523-97 "Rolled plate of carbon steel of ordinary quality" (for metal doors reinforced or protective), less often according to GOST 5632-72 "High-alloy steels and alloys corrosion-resistant, heat-resistant and heat-resistant".

Important: "Armored", "safe" metal doors, as well as "iron" doors do not exist by definition. Metal doors for residential premises are not manufactured in burglary resistance classes higher than V (GOST R 51113-97) for technical reasons - strengthening the strength properties entails an increase in the mass of the finished door block to values ​​that are incompatible with installation in ordinary wall openings and operation of doors with manual opening of the canvas. Massive doors of large classes of burglary resistance are used in bank vaults and have electromechanical control drives.

Simplified for understanding standards GOST 31173-2003.

GOST 31173-2003 classifies and standardizes metal doors according to:

resistance to burglary, determined by the class of strength characteristics and the class of protective properties of locking mechanisms - metal doors of conventional design with strength class M3 and III - IV class of security properties of locks according to GOST 5089-2003, reinforced metal doors with strength class M2 and III - IV class security properties of locks, protective metal doors with strength class M1 and IV class of security properties of locks;



Important: Strengthening the protective properties of metal doors (burglary resistance) depends on the strength properties of the door block (with an increase in strength characteristics from class M3 to M1, the resistance to burglary of a metal door increases). Even ordinary doors cannot have locks with security properties lower than class III, and the level of security properties increases from class I to class IV. The class of security properties of a lock is determined not by its design or trademark, but by the number of secrets that should be for locks with: class III cylinder mechanism - 10 thousand, class IV - 25 thousand; disk cylinder mechanism of class III - 200 thousand, class IV - 300 thousand; lever mechanism class III - 50 thousand, class IV - 100 thousand.

mechanical characteristics (strength classes) determined by the magnitude of static loads applied in the plane, in the zone of the free corner, in the zone of the web loops, as well as dynamic loads applied in the direction of opening the web and shock loads in both directions of opening the web.

Important: Strength class M1 has the best mechanical characteristics, strength class M3 - the worst, but any metal door sold today must have mechanical characteristics not lower than strength class M3;

• according to heat-shielding properties determined by the reduced heat transfer resistance - class 1 with reduced heat transfer resistance of at least 1.0 m2 °C / W, class 2 with reduced heat transfer resistance from 0.70 to 0.99 m2 °C / W, class 3 with a reduced heat transfer resistance of 0.40 -0.69 m2 ° C / W.

  Important: Metal doors of class 1 have the best heat-shielding properties, the worst - class 3, but any metal doors cannot have a reduced heat transfer resistance below the threshold value of class 3 - 0.4 m2. ° C / W, which corresponds to that used in European regulatory legal acts, the heat transfer coefficient Uwert is not more than 1/0.4 = 2.5 W/(m2K). It must be remembered that for Moscow from October 1, 2010, according to the norms of the City Program "Energy-saving housing construction in the city of Moscow for 2010-2014. and for the future until 2020 "the reduced resistance to heat transfer of enclosing structures (windows, balconies and external entrance doors) should be at least 0.8 m2. ° С / W, and according to EnEV2009 standards for external doors, the upper threshold value of the heat transfer coefficient is normalized no more than 1.3 W /(m2K). Therefore, in the capital, metal doors entering from the street must be certified for heat-shielding properties for classes 1 or 2;

air and water permeability, determined by the indicators of volume air tightness and water tightness limit - classes 1-3.

Important: The air and water permeability of a metal door deteriorates from class 1 to class 3, but the airtightness of any metal door for residential premises must be at least class 3 and not more than 27 m3 / (h m2);

according to sound insulation, determined by the airborne noise insulation index Rw - class 1 with a reduction in airborne noise from 32 dB, class 2 with a reduction in airborne noise of 26-31 dB, class 3 with a reduction in airborne noise of 20-25 dB.



Important: Metal doors of class 1 have the best soundproofing properties, the worst - class 3, but the airborne noise insulation index is determined in the frequency band from 100 to 3000 Hz, corresponding to colloquial speech, phone or alarm calls, a TV with built-in speakers, a radio, and does not characterize the ability a metal door to block the noise of cars, aircraft, etc., as well as structural noise transmitted through the rigidly connected structure of the house / building;

non-failure operation, determined by the number of door leaf opening/closing cycles. This value for internal metal doors must be at least 200 thousand, and for external entrance metal doors at least 500 thousand.

Important: A metal door must be certified for compliance with the norms / requirements of Russian regulatory legal acts, but with differentiation in terms of basic operational properties and burglary resistance. If the manufacturer/sales company claims that the metal door complies with foreign regulatory legal acts, then comparative information with similar (or similar) indicators of Russian standards must be provided.

Metal doors deserve more trust, for which not only a certificate has been provided, but also test reports confirming the compliance of operational parameters and resistance to burglary with the norms of Russian standards. Ideally, a metal door should have a passport in accordance with the requirements of GOST 31173-2003, which, in addition to manufacturing details and design features, indicates:

• mechanical class;
• reliability (opening cycles);
• breathability at P0 = 100 Pa (value in m3/(h.m2) or class);
• airborne sound insulation index Rw in dB;
• reduced resistance to heat transfer in m2. ° C / W.