One of the most important issues in creating comfortable living conditions in a house or apartment is a reliable, correctly calculated and installed, well-balanced heating system. That is why creating such a system is the most important task when organizing the construction of your own home or when carrying out major renovations in a high-rise apartment.

Despite the modern variety of heating systems of various types, the leader in popularity still remains a proven scheme: pipe circuits with coolant circulating through them, and heat exchange devices - radiators installed in the premises. It would seem that everything is simple, the radiators are located under the windows and provide the required heating... However, you need to know that the heat transfer from the radiators must correspond to both the area of ​​the room and a number of other specific criteria. Thermal calculations based on the requirements of SNiP are a rather complex procedure performed by specialists. However, you can do it on your own, naturally, with acceptable simplification. This publication will tell you how to independently calculate heating radiators for the area of ​​a heated room, taking into account various nuances.

But, first, you need to at least briefly familiarize yourself with existing heating radiators - the results of the calculations will largely depend on their parameters.

Briefly about existing types of heating radiators

• Steel radiators of panel or tubular design.
• Cast iron batteries.
• Aluminum radiators of several modifications.
• Bimetallic radiators.

Steel radiators

This type of radiator has not gained much popularity, despite the fact that some models are given a very elegant design. The problem is that the disadvantages of such heat exchange devices significantly exceed their advantages - low price, relatively low weight and ease of installation.

The thin steel walls of such radiators do not have enough heat capacity - they heat up quickly, but also cool down just as quickly. Problems can also arise with water hammer - welded joints of sheets sometimes leak. In addition, inexpensive models that do not have a special coating are susceptible to corrosion, and the service life of such batteries is short - usually manufacturers give them a fairly short warranty in terms of service life.

In the vast majority of cases, steel radiators are a one-piece structure, and it is not possible to vary the heat transfer by changing the number of sections. They have a rated thermal power, which must be immediately selected based on the area and characteristics of the room where they are planned to be installed. An exception is that some tubular radiators have the ability to change the number of sections, but this is usually done to order, during manufacture, and not at home.

Cast iron radiators

Representatives of this type of battery are probably familiar to everyone from early childhood - these are the types of accordions that were previously installed literally everywhere.

Perhaps such batteries MC -140-500 were not particularly elegant, but they faithfully served more than one generation of residents. Each section of such a radiator provided a heat output of 160 W. The radiator is prefabricated, and the number of sections, in principle, was not limited by anything.

There are currently many modern cast iron radiators on sale. They are already distinguished by a more elegant appearance, smooth outer surfaces that make cleaning easier. Exclusive versions are also produced, with an interesting relief pattern of cast iron casting.

With all this, such models fully retain the main advantages of cast iron batteries:

• The high heat capacity of cast iron and the massiveness of the batteries contribute to long-term retention and high heat transfer.
• Cast iron batteries, with proper assembly and high-quality sealing of connections, are not afraid of water hammer and temperature changes.
• Thick cast iron walls are little susceptible to corrosion and abrasive wear. Almost any coolant can be used, so such batteries are equally good for autonomous and central heating systems.

If we do not take into account the external characteristics of old cast iron batteries, then the disadvantages include the fragility of the metal (accentuated impacts are unacceptable), the relative complexity of installation, which is associated largely with massiveness. In addition, not all wall partitions can support the weight of such radiators.

Aluminum radiators

Aluminum radiators, having appeared relatively recently, quickly gained popularity. They are relatively inexpensive, have a modern, quite elegant appearance, and have excellent heat dissipation.

High-quality aluminum batteries can withstand pressures of 15 atmospheres or more and high coolant temperatures of about 100 degrees. At the same time, the thermal output from one section of some models sometimes reaches 200 W. But at the same time, they are lightweight (section weight is usually up to 2 kg) and do not require a large volume of coolant (capacity - no more than 500 ml).

Aluminum radiators are offered for sale as stacked batteries, with the ability to change the number of sections, and as solid products designed for a certain power.

Disadvantages of aluminum radiators:

• Some types are highly susceptible to oxygen corrosion of aluminum, with a high risk of gas formation. This places special demands on the quality of the coolant, which is why such batteries are usually installed in autonomous heating systems.
• Some aluminum radiators of a non-separable design, sections of which are made using extrusion technology, may, under certain unfavorable conditions, leak at the joints. In this case, it is simply impossible to carry out repairs, and you will have to replace the entire battery as a whole.

Of all aluminum batteries, the highest quality ones are those made using anodic oxidation of the metal. These products are practically not afraid of oxygen corrosion.

Externally, all aluminum radiators are approximately similar, so you need to read the technical documentation very carefully when making a choice.

Bimetallic heating radiators

Such radiators compete with cast iron ones in terms of reliability, and with aluminum ones in terms of thermal output. The reason for this is their special design.

Each section consists of two, upper and lower, steel horizontal collectors (item 1), connected by the same steel vertical channel (item 2). The connection into a single battery is made with high-quality threaded couplings (item 3). High heat transfer is ensured by the outer aluminum shell.

Steel internal pipes are made of metal that is not subject to corrosion or has a protective polymer coating. Well, under no circumstances does the aluminum heat exchanger come into contact with the coolant, and it is absolutely not afraid of corrosion.

This results in a combination of high strength and wear resistance with excellent thermal performance.

Prices for popular heating radiators

Heating radiators

Such batteries are not afraid of even very large pressure surges and high temperatures. They are, in fact, universal and suitable for any heating systems, however, they still show the best performance characteristics under conditions of high pressure in the central system - they are of little use for circuits with natural circulation.

Perhaps their only drawback is their high price compared to any other radiators.

For ease of reference, there is a table showing the comparative characteristics of radiators. Symbols in it:

• TS – tubular steel;
• Chg – cast iron;
• Al – ordinary aluminum;
• AA – aluminum anodized;
• BM – bimetallic.

	Chg	TS	Al	AA	BM
Maximum pressure (atm.)
working	6-9	6-12	10-20	15-40	35
crimping	12-15	9	15-30	25-75	57
destruction	20-25	18-25	30-50	100	75
Limitation on pH (hydrogen value)	6,5-9	6,5-9	7-8	6,5-9	6,5-9
Susceptibility to corrosion when exposed to:
oxygen	No	Yes	No	No	Yes
stray currents	No	Yes	Yes	No	Yes
electrolytic pairs	No	weak	Yes	No	weak
Section power at h=500 mm; Dt=70 ° , W	160	85	175-200	216,3	up to 200
Warranty, years	10	1	3-10	30	3-10

Video: recommendations for choosing heating radiators

You might be interested in information about what it is

How to calculate the required number of heating radiator sections

It is clear that a radiator installed in the room (one or more) must provide heating to a comfortable temperature and compensate for the inevitable heat loss, regardless of the weather outside.

The basic value for calculations is always the area or volume of the room. The professional calculations themselves are very complex and take into account a very large number of criteria. But for household needs you can use simplified methods.

The simplest methods of calculation

It is generally accepted that to create normal conditions in a standard living space, 100 W per square meter of area is sufficient. Thus, you just need to calculate the area of ​​the room and multiply it by 100.

Q = S× 100

Q– required heat transfer from heating radiators.

S– area of ​​the heated room.

If you plan to install a non-separable radiator, then this value will become a guideline for selecting the required model. In the case where batteries are installed that allow the number of sections to be changed, another calculation should be made:

N = Q/ Qus

N– calculated number of sections.

Qus– specific thermal power of one section. This value must be indicated in the technical data sheet of the product.

As you can see, these calculations are extremely simple and do not require any special knowledge of mathematics - just a tape measure to measure the room and a piece of paper for calculations. In addition, you can use the table below - it shows already calculated values ​​for rooms of different sizes and certain capacities of heating sections.

Section table

However, you need to remember that these values ​​are for the standard ceiling height (2.7 m) of a high-rise building. If the height of the room is different, then it is better to calculate the number of battery sections based on the volume of the room. For this, an average indicator is used - 41 V t t heat output per 1 m³ of volume in a panel house, or 34 W in a brick house.

Q = S × h× 40 (34 )

Where h– ceiling height above floor level.

Further calculations are no different from those presented above.

Detailed calculation taking into account features premises

Now let's move on to more serious calculations. The simplified calculation method given above can present a “surprise” to the owners of a house or apartment. When installed radiators do not create the required comfortable microclimate in residential premises. And the reason for this is a whole list of nuances that the considered method simply does not take into account. Meanwhile, such nuances can be very important.

So, the area of ​​the room and the same 100 W per m² are again taken as a basis. But the formula itself already looks a little different:

Q = S× 100 × A × B × C ×D× E ×F× G× H× I× J

Letters from A before J Coefficients are conventionally designated that take into account the characteristics of the room and the installation of radiators in it. Let's look at them in order:

A is the number of external walls in the room.

It is clear that the higher the contact area between the room and the street, that is, the more external walls there are in the room, the higher the overall heat loss. This dependence is taken into account by the coefficient A:

• One external wall A = 1.0
• Two external walls - A = 1.2
• Three outer walls - A = 1.3
• All four external walls are A = 1.4

B – orientation of the room to the cardinal points.

The maximum heat loss is always in rooms that do not receive direct sunlight. This is, of course, the northern side of the house, and the eastern side can also be included here - the rays of the Sun appear here only in the mornings, when the luminary has not yet reached its full power.

The southern and western sides of the house are always heated by the Sun much more strongly.

Hence the coefficient values IN :

• The room faces north or east - B = 1.1
• South or west rooms – B = 1, that is, it may not be taken into account.

C is a coefficient that takes into account the degree of insulation of the walls.

It is clear that heat loss from the heated room will depend on the quality of the thermal insulation of the external walls. Coefficient value WITH are taken equal to:

• Middle level - the walls are laid with two bricks, or their surface insulation is provided with another material - C = 1.0
• External walls are not insulated - C = 1.27
• High level of insulation based on thermal engineering calculations – C = 0.85.

D – features of the climatic conditions of the region.

Naturally, it is impossible to put all the basic indicators of the required heating power “with the same brush” - they also depend on the level of winter negative temperatures characteristic of a particular area. This takes into account the coefficient D. To select it, the average temperatures of the coldest ten-day period of January are taken - usually this value is easy to check with the local hydrometeorological service.

• — 35° WITH and below - D= 1.5
• — 25÷ — 35 ° WITH – D= 1.3
• up to – 20 ° WITH – D= 1.1
• not lower than – 15 ° WITH – D= 0.9
• not lower than – 10 ° WITH – D= 0.7

E – coefficient of ceiling height of the room.

As already mentioned, 100 W/m² is an average value for standard ceiling heights. If it differs, a correction factor must be entered E:

• Up to 2.7 m – E = 1,0
• 2,8 – 3, 0 m – E = 1,05
• 3,1 – 3, 5 m – E = 1, 1
• 3,6 – 4, 0 m – E = 1.15
• More than 4.1 m – E = 1.2

F – coefficient taking into account the type of room located higher

Installing a heating system in rooms with cold floors is a pointless exercise, and owners always take action in this matter. But the type of room located above often does not depend on them in any way. Meanwhile, if there is a living or insulated room on top, then the overall need for thermal energy will significantly decrease:

• cold attic or unheated room - F= 1.0
• insulated attic (including insulated roof) – F= 0.9
• heated room - F= 0.8

G – factor taking into account the type of windows installed.

Different window designs are subject to heat loss differently. This takes into account the coefficient G:

• conventional wooden frames with double glazing – G= 1.27
• the windows are equipped with single-chamber double-glazed windows (2 glasses) – G= 1.0
• single-chamber double-glazed window with argon filling or double-glazed window (3 glasses) - G= 0.85

N – coefficient of the glazing area of ​​the room.

The total amount of heat loss also depends on the total area of ​​windows installed in the room. This value is calculated based on the ratio of the window area to the room area. Depending on the result obtained, we find the coefficient N:

• Ratio less than 0.1 – H = 0, 8
• 0.11 ÷ 0.2 – H = 0, 9
• 0.21 ÷ 0.3 – H = 1, 0
• 0.31÷ 0.4 – H = 1, 1
• 0.41 ÷ 0.5 – H = 1.2

I is a coefficient that takes into account the radiator connection diagram.

Their heat transfer depends on how the radiators are connected to the supply and return pipes. This should also be taken into account when planning the installation and determining the required number of sections:

• a – diagonal connection, supply from above, return from below – I = 1.0
• b – one-way connection, supply from above, return from below – I = 1.03
• c – two-way connection, both supply and return from below – I = 1.13
• d – diagonal connection, supply from below, return from above – I = 1.25
• d – one-way connection, supply from below, return from above – I = 1.28
• e – one-sided bottom connection of return and supply – I = 1.28

J is a coefficient that takes into account the degree of openness of installed radiators.

Much also depends on how open the installed batteries are to free heat exchange with the room air. Existing or artificially created barriers can significantly reduce the heat transfer of the radiator. This takes into account the coefficient J:

a – the radiator is located openly on the wall or not covered by a window sill – J= 0.9

b – the radiator is covered from above with a window sill or shelf – J= 1.0

c – the radiator is covered from above by a horizontal projection of the wall niche – J= 1.07

d – the radiator is covered from above by a window sill, and from the front sides — partsdirectly covered with a decorative casing - J= 1.12

e – the radiator is completely covered with a decorative casing– J= 1.2

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Well, finally, that's all. Now you can substitute the required values ​​and coefficients corresponding to the conditions into the formula, and the output will be the required thermal power for reliable heating of the room, taking into account all the nuances.

After this, all that remains is to either select a non-separable radiator with the required thermal output, or divide the calculated value by the specific thermal power of one section of the battery of the selected model.

Surely, to many, such a calculation will seem overly cumbersome, in which it is easy to get confused. To make the calculations easier, we suggest using a special calculator - it already contains all the required values. The user can only enter the requested initial values ​​or select the required items from the lists. The “calculate” button will immediately lead to an exact result, rounded up.

You can calculate heating radiators by area using a calculator posted on any website. But the data will not be accurate. There are many calculators (programs) for calculating sections of heating radiators, but accurate information can only be obtained if you carry out the calculation manually individually for each room.

Simplified options for calculating heating radiators in a house

First method: Calculation by room volume

It is prescribed in the provisions of SNiP and is applicable for panel houses. The Rules propose as a norm to take 41 W of heating power per cubic meter of heated space. To calculate the number of required sections, it is enough to divide the volume of the room by the power of one section of installed radiators (this parameter is indicated by the manufacturer in the accompanying technical documentation).

Second method: Calculation by area of ​​premises

This calculation method is aimed at rooms with ceilings up to 2500 mm, and 100 W of power per square square of area is taken as the norm. To calculate the number of sections, it is necessary to divide the area of ​​the room by the power of one section (indicated in the technical documentation of the radiators).

Approximate calculation of the number of radiator sections for a typical room

N=S/P*100, Where:

• N- Number of sections (the fractional part is rounded according to the rules of mathematical rounding))
• S- Room area in m2
• P- Heat transfer of 1 section, Watt

For these calculation options, we apply a number of amendments. For example, if the room has a balcony, or more than two windows, or it is located on the corner of the building, then it is recommended to add another 20% to the resulting number of sections. If the calculation results in the final result (number of sections) being a fractional number, then it should be rounded up to the nearest whole number.

Note: the resulting value is calculated for ideal conditions. That is, there is no additional heat loss in the house, the heating system itself works efficiently, windows and doors are hermetically closed, and neighboring rooms are also heated. In real conditions, more sections may be required.

Accurate calculation of the required number of radiator sections

Above are simplified methods for calculating radiators, which are relevant for typical apartments with standard parameters. With their help, it is unrealistic to obtain adequate results for private residential buildings and apartments in modern new buildings. To do this, use a special formula:
KT = 100W/m2 * S * K1 * K2 * K3 * K4 * K5 * K6 * K7,

Where the standard of 100 W per square meter is also taken as a basis, the total area of ​​​​the room is also supplemented with coefficients, the values ​​of which are given below:

K1 - coefficient taking into account the glazing of window openings:

• for windows with conventional double glazing: 1.27;
• for windows with double glazing: 1.0;
• for windows with triple glazing: 0.85;

K2 - wall thermal insulation coefficient:

• low degree of thermal insulation: 1.27;
• good thermal insulation (masonry in two bricks or a layer of insulation): 1.0;
• high degree of thermal insulation: 0.85;

K3 - ratio of window area to floor area in the room:

• 50%: 1.2;
• 40%: 1.1;
• 30%: 1.0;
• 20%: 0.9;
• 10%: 0.8;

K4 is a coefficient that allows you to take into account the average air temperature in the coldest week of the year:

• for -35°C: 1.5;
• for -25°C: 1.3;
• for -20°C: 1.1;
• for -15°C: 0.9;
• for -10°C: 0.7;

K5 - adjusts the heat demand taking into account the number of external walls:

• one wall: 1.1;
• two walls: 1.2;
• three walls: 1.3;
• four walls: 1.4;

K6 - taking into account the type of room located above:

• cold attic: 1.0;
• heated attic: 1.0;
• heated living space: 1.0;

K7 - coefficient taking into account the height of ceilings:

• at 2.5 m: 1.0;
• at 3.0 m: 1.05;
• at 3.5 m: 1.1;
• at 4.0 m: 1.15;
• at 4.5 m: 1.2;

When building a house, people wonder how to calculate the number of heating radiator sections? An insufficient number of sections will not warm the room to a comfortable level, and an excess of them will make the temperature in it too high, which will force you to open the windows, creating the risk of catching a cold. Therefore, this issue should be approached with special care.

The type of radiator is one of the first components that must be taken into account when performing calculations. When purchasing radiators, you should also remember about the relevant documentation, which guarantees that the product will last for a certain minimum period of time.

Today, the most common are cast iron radiators, which, despite their large mass and rather large dimensions, are considered to be of the highest quality.

More modern ones are bimetallic radiators. They have many advantages, but are not cheap. Because of this, most people are interested in the question of how to calculate the number of radiator sections, because one extra section is an impressive additional cost. Therefore, the correct calculation of their quantity is the first thing that needs to be done before purchasing and installing them.

Indicators required for calculations

When making calculations to determine the required number of radiator sections, the following data should be taken into account:

1. S premises.
2. Total number of window openings.
3. Type and power indicators.
4. Interior floor thickness.

It is also necessary to take into account the fact that all radiators have technical documentation with the specified power. Accordingly, the technical indicators of each radiator are purely individual.

Important! In order for the room temperature to be comfortable, the heating power per 1 m2 of area should be in the range of 39-40 W.

Calculation by area

The calculation of the number of radiator sections and the required heated surface area is carried out taking into account many indicators.

Calculation of the number of radiator sections

The standard power value, depending on the material used for manufacturing, has the following indicators:

1. Cast iron - 160 W.
2. Aluminum - 200 W.
3. Bimetallic - 180 W.
4. Steel - from 110 to 150 W.

The number of radiators is often equal to the number of windows installed. Sometimes radiators are installed on blank walls, which significantly lower the temperature level.

For example, S of a room is 25m2:

25 x100(W) = 2500W = 2.5 kW.

We divide the resulting number by the power value of the section. Let's say we have a steel radiator with a factory power of 150 W. Respectively:

2500/150 = 17 pcs.

It is advisable to round to a larger value; it is rounded to a smaller value only if the room has minimal heat loss or is equipped with another heat source, for example, a gas stove.

Important! Do not install radiators with more than 10 sections, as when this numerical threshold is exceeded, the outer sections become ineffective.

Multi-section cast iron radiator

The above calculation of the number of sections of heating radiators is rough and generalized, since no additional indicators are taken into account here, which include:

1. Temperature range.
2. Number of installed double-glazed windows.
3. Overall value of installed windows.
4. Size and number of external walls.
5. Thickness and type of insulation used to insulate walls.
6. The width of the masonry material used in the construction of walls.

Table for calculating the number of radiator sections by area

Additional conditions taken into account in calculations

There are a large number of additional indicators that are taken into account when making calculations. We have already discussed some of them above, and we will consider others, which imply additional conditions, below. These include the following:

1. If the room is equipped with a balcony, 20% is added to the result obtained.
2. If there are two window openings in the room, the result increases by 30%.
3. High-quality and well-installed double-glazed windows reduce the value by 10-15%.
4. If you plan to install a grille or some kind of decor, the figure increases by 10-15%.
5. To obtain some power reserve, which may be useful when the temperature of the region drops below average, a certain reserve is provided. Accordingly, the obtained value must be increased by 15%.
6. The coolant does not always have the temperature specified by the standard. Sometimes it is 10-15 degrees cooler. Therefore, the radiator power must be increased by 18-23%.

Bimetallic radiator with diagonal connection

As you already understand, calculating the required number of radiators is quite a responsible and serious issue that requires a serious approach. Based on this, it is recommended to make an accurate calculation taking into account all of the above components and some correction factors.

Important! Be sure to consider as many additional conditions as possible. The more there are, the more accurate the result of the calculations.

The procedure for performing accurate calculations

Multi-storey buildings in most cases have a standard layout, but in the private sector everything is completely different. How to calculate the required number of sections in this case? When carrying out such calculations, it will be necessary to take into account many indicators, including the height of the ceilings, the number of windows, their sizes and more.

The peculiarity of this calculation is that it uses a variety of correction factors, which make it possible to obtain the most accurate value, taking into account all the features of the room.

Bimetallic radiator with bottom connection. Heat transfer with this connection is 10-30% lower

The formula for calculating the number of sections of heating radiators using this method is as follows:

Kt*P*K1*K2*K3*K4*K5*K6*K7, Where:

• Kt - the amount of heat required for a single room is equal to 100 W per 1 m2.
• P - total area.
• K1 - degree of window glazing - 0.85 - 1.3.
• K2 - thermal insulation degree - 1.0 - 1.27.
• K3 - ratio S of floor and window - 0.8 - 1.2.
• K4 - average outside air t on the coldest day - 1.5-0.7.
• K5 - presence of walls - 1.1 - 1.4.
• K6 - type of room located on the floor above - 0.8 - 1.0.
• K7- Ceiling height - 1.0 - 1.2.

Application of the above formula makes it possible to take into account most of the existing nuances, which makes the result the most accurate. Next, the result is divided by the heat transfer value of one section and rounded up to the nearest whole number.

A properly constructed heating system creates comfortable living conditions in a house, apartment or any other type of room. Its main element is a battery or, as it is often called, a heating radiator. When designing a system yourself, it is important not only to select a product according to its technical characteristics, but also to calculate the heating radiators. Only in this case will the system be effective and balanced.

When installing radiators in a house, not only the characteristics are important, but also the number of batteries

Heating system design

In any heating system that uses water as a coolant, two basic elements always apply- pipes and radiators. Heating of the room occurs in the following way: heated water is supplied through pipes under pressure or by gravity into the water supply system. This system contains batteries that are filled with water. Having filled the radiator, the water enters the pipe leading it back to the place of heating. There it is again heated to the required temperature and again sent to the battery. That is, the coolant moves in a circle.

The heating system must have pipes and radiators

To achieve the greatest efficiency, batteries are located according to developed rules. It is common to place them in places where cold air enters, so they are mounted under window sills.

As a result, cold air mixes faster with warm air coming from the radiator, and fewer different temperature zones arise.

During installation, the following recommendations should be observed:

Installing a wide heating device forms a thermal curtain, but it is not advisable to exceed the calculated number of radiator sections so as not to lose battery power. Therefore, if the window is wide, you should select a heating device so that it has an elongated shape, or install several radiators.

Covering the heaters with any objects may reduce the heat transfer efficiency of the system.

This is due to an increase in dust formation due to increased air speed and an artificial barrier to warm flows.

Types of heating devices

Batteries are used to transfer heat from heated water to the surrounding area. The operating principle of the products is based on the use of materials as heaters that are capable of taking energy from the coolant and transferring it in the form of heat radiation. Therefore, one of the main characteristics of a radiator is transmission efficiency.

The efficiency of radiators is affected by the material and shape of the sections

In addition to the material used, this characteristic is also influenced by the design features of the products. They must take into account that warm air, due to its rarefied state, is lighter than cold air. Passing through the heating radiator, it heats up and rises, drawing in a portion of cold air, which also heats up.

There are several options that differ in appearance, shape of sections and material used to create the product. Modern batteries, depending on the material used for their manufacture, are divided into the following types:

• cast iron;
• aluminum;
• steel;
• bimetallic;
• copper;
• plastic.

Modern radiators can consist of different metals, and also contain several types of metals

In addition to heat transfer, an important parameter is the ability of radiators to withstand the required pressure created in the heating system. Thus, when heating a multi-storey building, a pressure of about 8-9.5 atmospheres is considered normal. But when the circuit is built incorrectly, it can drop to 5 atmospheres. For two-story buildings, the optimal indicator is considered to be 1.5−2 atmospheres. The same value is acceptable for private households.

If the battery is designed for less pressure and a hydraulic shock occurs in the circuit, it will simply rupture with all the ensuing consequences. Therefore, preference is most often given to cast iron, aluminum and bimetallic structures.

Cast iron products

Cast iron radiators resemble an accordion in appearance. Their distinguishes simplicity of design and accuracy. Today they are especially popular among designers when creating retro style. Cast iron batteries are characterized by low thermal conductivity: in order to warm the radiator to +45°C, the carrier temperature must be about +70...+80°C. The devices are mounted on reinforced brackets or mounted on special legs.

Cast iron batteries have fairly low thermal conductivity, but take a long time to cool down

Batteries of this type are assembled from sections that are connected to each other using a key. The connection points of the parts are carefully sealed with paronite or rubber gaskets. As a rule, one section of a modern radiator has a thermal power of about 140 W (versus 170 W of the Soviet model). One section holds about one liter of water.

The advantages of cast iron are that it is not subject to corrosion, so it can be used with water of any quality.

The service life of the device is about 35 years. No special care is needed for this type of battery. Cast iron batteries take a long time to heat up, but at the same time they take a long time to cool down. They can easily withstand pressure of 12 atmospheres. On average, one section can heat from 0.66 m² to 1.45 m² of area.

Aluminum heater

There are two ways to make aluminum batteries - casting and extrusion. The first type of device is made in the form of a single piece, and the second - sectional. Cast batteries are designed for use at a pressure of 16-20 atmospheres, and extruded batteries - from 10 to 40 atmospheres. Preference is given to cast radiators due to greater reliability.

Aluminum radiators have good thermal conductivity, but are susceptible to rapid contamination

The heat transfer of the battery, according to the manufacturers, can reach 200 W at a carrier temperature of +70°C. In practice, when the coolant is heated to +50°C, an aluminum section measuring 100 x 600 x 80 mm heats about 1.2 m³, which corresponds to a heat transfer of 120 W. The volume of one section is about 500 ml.

It should be noted that such heaters are sensitive to the quality of the coolant and quickly become dirty with the risk of gas formation. When installing them, a water purification system must be provided.

Recently, aluminum models have appeared on the market that use anodic oxidation treatment. This makes it possible to virtually eliminate the occurrence of oxygen corrosion.

Bimetallic structures

Bimetallic radiators are assembled from steel pipes and aluminum panels. Due to the use of aluminum, they are characterized by high heat transfer. This type of battery is durable and has a service life of about 20 years. At a coolant temperature of +70°C, the average heat transfer is 170−190 W. Such a device can withstand pressure up to 35 atmospheres.

This type of radiator contains two types of metals and combines their properties

Bimetallic radiators are available with different center distances: 20, 30, 35, 50, 80 cm. This allows them to be built into various niche shapes, even completely square ones. Sections can be assembled in any quantity, and they are completely identical on the left and right.

To protect against corrosion, the internal pipes are coated with polymers. They are not subject to electrochemical corrosion. Such radiators are not afraid of water hammer and high temperatures. Therefore, bimetallic radiators are products with the best performance provided by the aluminum casing, they are strong, durable and stable due to the internal steel structure.

Their only drawback is their high price.

Simple calculation

If everything has been decided on the type of batteries used, then you can begin to determine the optimal number of batteries and their sections. To do this, you need to measure the area of ​​the room in which you plan to install radiators, and find out the power of one section of the battery planned for installation. Its value is taken from the product passport. After which it will be quite easy to calculate the required number of batteries per room.

It is very easy to calculate the number of sections in a house using the formula

The volume of a room is calculated using the formula: V = S *H, m³, where:

• S - room area (width times length), m².
• H - room height, m.

It is believed that to heat 1 m² it is necessary to provide a thermal power of 100 W per hour. This rule was applied in Soviet times for rooms with a ceiling height of 2.5–2.7 m and did not take into account the thickness and type of partitions in the building, the number of windows and doors, and the climate zone.

K = Q1 / Q2, where:

• K - number of sections, pcs.
• Q1 - required thermal power, W.
• Q2 - heat transfer of one section, W.

For example, for a room of 20 m² with two windows and a ceiling height of 2.7 meters, you will need 2 kW of power per hour. Therefore, when using a bimetallic radiator with a section power of 170 W, you will need their number equal to: K = 2000 W / 170 W = 11.7. That is, 12 battery sections are needed for the entire area. Since radiators are located under the windows, depending on their number, the number of batteries is determined. For the case under consideration, it will be necessary to purchase 2 batteries of 6 sections each.

But if the height of the room differs from 2.7 m, then the number of sections should be determined taking into account the volume. To do this, a coefficient is introduced equal to 41 W of thermal power per 1 m² in the case of a panel house and 34 W if the house is brick. The calculation is carried out using the formula: P = V* k, where:

• P - calculated power, W.
• V is the volume of the room, m³.
• k - thermal power coefficient, W.

Calculation taking into account coefficients

In order to accurately calculate heating radiators based on the area of ​​the room, you need to take into account a number of parameters. The calculation is still based on the rule of needing 100 W per 1 m² of area, but the formula taking into account the coefficients will look different:

Q = S * 100 * K1 * K2 * K3 * K4 * K5 * K6* K7 * K8 * K9, where:

1. K1 - number of external walls. By adding this parameter to the formula, it is taken into account that the more walls border the external environment, the more heat loss occurs. So, for one wall it is taken equal to one, for two - 1.2, three - 1.3, four - 1.4.
2. K2 - location relative to cardinal directions. There are so-called cold sides - northern and eastern, which are practically not warmed by the sun. If the external walls are located relative to the north and east, then the coefficient is taken equal to 1.1.
3. K3 - insulation. Takes into account the thickness of the walls and the material from which they are made. If the external walls are not insulated, the coefficient is 1.27.
4. K4 - features of the region. To calculate its value, the average temperature of the coldest month in the region is taken. If it is -35°C and below, K4 = 1.5, when the temperature is in the range from -25°C to -35°C, K4 = 1.3, not lower than -15°C - K4 = 0.9 , more than -10°C - K4 = 0.7.
5. K5 - room height. If the ceiling is up to 3 meters, K5 is taken equal to 1.05. From 3.1 to 3.5 - K5 = 1.1, if 3.6−4.0 m, K5 = 1.15, and more than 4.1 m - K5 = 1.2.
6. K6 takes into account heat loss through the ceiling. If the room above is unheated, then the coefficient is taken equal to one. If it is insulated, K6 = 0.9, heated - K6 = 0.8.
7. K7 - window openings. With a single-chamber package installed, K7 is taken equal to one, with a two-chamber package - 0.85. If frames with two glasses are installed in the openings, K7 = 0.85.
8. K8 takes into account the radiator connection diagram. So, this coefficient can vary from one to 1.28. The best connection is diagonal, in which the coolant is supplied from above and the return is connected from below, and the worst is one-sided.
9. K9 takes into account the degree of openness. The best position is when the battery is located on the wall, then the coefficient is taken equal to 0.9. If it is closed at the top and front with a decorative grille, K7 = 1.2, only at the top - K7 = 1.0.

Substituting all the values, the answer gives the thermal power required to heat the room, taking into account many factors. And then the calculation of sections and the number of batteries is done by analogy with a simple calculation.

It is very important to buy modern, high-quality and efficient batteries. But it is much more important to correctly calculate the number of radiator sections so that during the cold season it properly warms the room and does not have to think about installing additional portable heating devices that will increase the cost of heating.

SNiP and basic regulations

Today we can name a huge number of SNiPs that describe the rules for the design and operation of heating systems in various premises. But the most understandable and simple is the document “Heating, ventilation and air conditioning” numbered 2.04.05.

It describes in detail the following sections:

1. General provisions regarding the design of heating systems
2. Rules for the design of building heating systems
3. Features of the heating system

Heating radiators must also be installed in accordance with SNiP number 3.05.01. It prescribes the following installation rules, without which the calculations made for the number of sections will be ineffective:

1. The maximum width of the radiator should not exceed 70% of the same characteristic of the window opening under which it is installed
2. The radiator must be mounted in the center of the window opening (a minor error is allowed - no more than 2 cm)
3. Recommended space between radiators and wall is 2-5 cm
4. The height above the floor should not be more than 12 cm
5. The distance to the window sill from the top point of the battery is at least 5 cm
6. In other cases, to improve heat transfer, the surface of the walls is covered with reflective material

It is necessary to follow such rules so that air masses can circulate freely and replace each other.

Read also, different types of heating radiators

Calculation by volume

In order to accurately calculate the number of heating radiator sections required for efficient and comfortable heating of a living space, its volume should be taken into account. The principle is quite simple:

1. Determining the heat requirement
2. Find out the number of sections capable of giving it away

SNiP prescribes taking into account the heat requirement for any room - 41 W per 1 cubic meter. However, this indicator is very relative. If the walls and floor are poorly insulated, it is recommended to increase this value to 47-50 W, because some of the heat will be lost. In situations where a high-quality heat insulator has already been laid on the surfaces, high-quality PVC windows have been installed and drafts have been eliminated, this figure can be taken as 30-34 W.

If there are heating systems in the room, the heat demand must be increased to 20%. Part of the thermal heated air masses will not be passed through the screen, circulating inside and quickly cooling.

Formulas for calculating the number of sections by room volume, with an example

Having decided on the need for one cube, you can begin calculations (example using specific numbers):

1. In the first step, we calculate the volume of the room using a simple formula: [height length Width] (3x4x5=60 cubic meters)
2. The next stage is to determine the heat requirement for the specific room in question using the formula: [volume]*[requirement per cubic meter] (60x41=2460 W)
3. You can determine the desired number of ribs using the formula: (2460/170=14.5)
4. It is recommended to round up - we get 15 sections

Many manufacturers do not take into account that the coolant circulating through the pipes is far from the maximum temperature. Consequently, the power of the ribs will be lower than the specified limit value (this is what is written in the passport). If there is no minimum power indicator, then the available one is underestimated by 15-25% to simplify calculations.

Calculation by area

The previous calculation method is an excellent solution for rooms with a height of more than 2.7 m. In rooms with lower ceilings (up to 2.6 m), you can use another method, taking the area as a basis.

In this case, calculating the total amount of thermal energy, the need per square meter. m is taken equal to 100 W. There is no need to make any adjustments to it for now.

Formulas for calculating the number of sections by room area, with an example

1. At the first stage, the total area of ​​the room is determined: [length Width] (5x4=20 sq.m.)
2. The next step is to determine the heat required to heat the entire room: [area]* [requirement per sq. m.] (100x20=2000 W)
3. In the passport attached to the heating radiator, you need to find out the power of one section - the average for modern models is 170 W
4. To determine the required number of sections, use the formula: [total heat demand]/[power of one section] (2000/170=11.7)
5. We introduce correction factors ( discussed below)
6. It is recommended to round up – we get 12 sections

The methods discussed above for calculating the number of radiator sections are perfect for rooms whose height reaches 3 meters. If this figure is greater, it is necessary to increase the thermal power in direct proportion to the increase in height.

If the entire house is equipped with modern plastic windows, in which the heat loss coefficient is as low as possible, it becomes possible to save money and reduce the result by up to 20%.

It is believed that the standard temperature of the coolant circulating through the heating system is 70 degrees. If it is below this value, it is necessary to increase the result by 15% for every 10 degrees. If it is higher, on the contrary, reduce it.

Premises with an area of ​​more than 25 square meters. m. heating with one radiator, even consisting of two dozen sections, will be extremely problematic. To solve this problem, it is necessary to divide the calculated number of sections into two equal parts and install two batteries. In this case, the heat will spread throughout the room more evenly.

If there are two window openings in the room, heating radiators should be placed under each of them. They must be 1.7 times more powerful than the nominal power determined in the calculations.

Having purchased stamped radiators where sections cannot be divided, it is necessary to take into account the total power of the product. If it is not enough, you should consider buying a second battery of the same type or one with a slightly lower heat capacity.

Correction factors

Many factors can influence the final result. Let's consider in what situations it is necessary to make correction factors:

• Windows with regular glazing – magnifying factor 1.27
• Insufficient thermal insulation of walls - increasing factor 1.27
• More than two window openings per room - magnifying factor 1.75
• Manifolds with bottom wiring – magnifying factor 1.2
• Reserve in case of unforeseen situations – increasing factor 1.2
• Use of improved thermal insulation materials – reduction factor 0.85
• Installation of high-quality thermal insulating double-glazed windows – reduction factor 0.85

The number of amendments made to the calculation can be huge and depends on each specific situation. However, it should be remembered that it is much easier to reduce the heat output of a heating radiator than to increase it. Therefore, all roundings are made upward.

Let's sum it up

If you need to make the most accurate calculation of the number of radiator sections in a complex room, do not be afraid to turn to specialists. The most accurate methods, which are described in specialized literature, take into account not only the volume or area of ​​the room, but also the temperature outside and inside, the thermal conductivity of the various materials from which the frame of the house is built, and many other factors.

Of course, you can not be afraid and add several edges to the result. But an excessive increase in all indicators can lead to unjustified expenses, which are not immediately, sometimes and not always, able to be recouped.