Standards for sections of heating batteries in an apartment. Steel heating radiators. Calculation of the power of steel heating radiators, taking into account the area of the room and heat loss. Approximate calculation for standard premises

Comfortable living conditions in winter depend entirely on the adequacy of the heat supply to residential premises. If this is a new building, for example, on a summer cottage or personal plot, then you need to know how to calculate heating radiators for a private house.

All operations boil down to calculating the number of radiator sections and are subject to a clear algorithm, so there is no need to be a qualified specialist - every person will be able to make a fairly accurate thermal calculation of their home.

Why is an accurate calculation necessary?

The heat transfer of heat supply devices depends on the material of manufacture and the area of individual sections. Not only the warmth in the house, but also the balance and efficiency of the system as a whole depends on correct calculations: an insufficient number of installed radiator sections will not provide adequate warmth in the room, and an excessive number of sections will hurt your pocket.

For calculations, it is necessary to determine the type of batteries and heating system. For example, the calculation of aluminum heat supply radiators for a private house differs from other elements of the system. Radiators are made of cast iron, steel, aluminum, anodized aluminum and bimetallic:

The most famous are cast iron batteries, the so-called “accordions”. They are durable, resistant to corrosion, have a section power of 160 W at a height of 50 cm and a water temperature of 70 degrees. A significant drawback of these devices is the unsightly appearance, but modern manufacturers produce smooth and quite aesthetic cast iron batteries, retaining all the advantages of the material and making them competitive.

Aluminum radiators are superior in thermal power to cast iron products; they are durable and light in weight, which gives an advantage during installation. The only drawback is susceptibility to oxygen corrosion. To eliminate it, the production of anodized aluminum radiators has been adopted.

Steel appliances do not have sufficient thermal power, cannot be disassembled and sections can be enlarged if necessary, and are susceptible to corrosion, so they are not popular.

Bimetallic heating radiators are a combination of steel and aluminum parts. The coolants and fasteners in them are steel pipes and threaded connections covered with an aluminum casing. The disadvantage is the rather high cost.

Based on the type of heating system, a distinction is made between single-pipe and two-pipe connection of heating elements. In multi-storey residential buildings, a single-pipe heating system is mainly used. The disadvantage here is the rather significant difference in the temperature of the incoming and outgoing water at different ends of the system, which indicates the uneven distribution of thermal energy among the battery devices.

To evenly distribute thermal energy in private homes, you can use a two-pipe heating system, when hot water is supplied through one pipe, and cooled water is discharged through the other.

In addition, the exact calculation of the number of heating radiators in a private house depends on the connection diagram of the devices, the height of the ceiling, the area of window openings, the number of external walls, the type of room, and the closeness of the devices. decorative panels and from other factors.

Remember! It is necessary to correctly calculate the required number of heating radiators in a private house in order to guarantee sufficient heat in the room and ensure financial savings.

Types of heating calculations for a private house

The type of calculation of heating radiators for a private house depends on the goal, that is, how accurately you want to calculate heating radiators for a private house. There are simplified and exact methods, as well as by area and volume of the calculated space.

According to the simplified or preliminary method, calculations are reduced to multiplying the area of the room by 100 W: the standard value of sufficient thermal energy per square meter, and the calculation formula will take the following form:

Q = S*100, where

Q – required heat power;

S – estimated area of the room;

The required number of sections of collapsible radiators is calculated using the formula:

N = Q/Qx, where

N – required number of sections;

Qx – specific power of the section according to the product data sheet.

Since these formulas for the height of the room are 2.7 m, correction factors must be entered for other values. Calculations boil down to determining the amount of heat per 1 m3 of room volume. The simplified formula looks like this:

Q = S*h*Qy, where

H – room height from floor to ceiling;

Qy – average thermal power depending on the type of fencing, for brick walls it is 34 W/m3, for panel walls– 41 W/m3.

These formulas cannot guarantee comfortable conditions. Therefore, accurate calculations are required that take into account all the associated features of the building.

Accurate calculation of heating devices

The most accurate formula for the required thermal power is as follows:

Q = S*100*(K1*K2*…*Kn-1*Kn), where

K1, K2 ... Kn – coefficients depending on various conditions.

What conditions affect the indoor microclimate? For accurate calculation, up to 10 indicators are taken into account.

K1 is an indicator depending on the number of external walls; the more surface is in contact with the external environment, the greater the loss of thermal energy:

with one external wall the indicator is equal to one;
if there are two external walls - 1.2;
if there are three external walls - 1.3;
if all four walls are external (i.e. the building is one-room) - 1.4.

K2 - takes into account the orientation of the building: it is believed that rooms are well heated if they are located in the south and west direction, here K2 = 1.0, and vice versa is not enough - when the windows face north or east - K2 = 1.1. One can argue with this: in the eastern direction the room still warms up in the morning, so it is more advisable to use a coefficient of 1.05.

K3 – indicator of insulation of external walls, depends on the material and degree of thermal insulation:

for external walls of two bricks, as well as when using insulation for non-insulated walls, the indicator is equal to one;
for non-insulated walls – K3 = 1.27;
when insulating a home based on thermal engineering calculations according to SNiP - K3 = 0.85.

K4 is a coefficient that takes into account the lowest temperatures of the cold period of the year for a specific region:

up to 35 °C K4 = 1.5;
from 25 °C to 35 °C K4 = 1.3;
up to 20 °C K4 = 1.1;
up to 15 °C K4 = 0.9;
up to 10 °C K4 = 0.7.

K5 - depends on the height of the room from floor to ceiling. The standard height is h = 2.7 m with an indicator equal to one. If the height of the room differs from the standard, a correction factor is introduced:

2.8-3.0 m – K5 = 1.05;
3.1-3.5 m – K5 = 1.1;
3.6-4.0 m – K5 = 1.15;
more than 4 m – K5 = 1.2.

K6 is an indicator that takes into account the nature of the room located above. The floors of residential buildings are always insulated, the rooms above can be heated or cold, and this will inevitably affect the microclimate of the calculated space:

for a cold attic, and also if the room above is not heated, the indicator will be equal to one;
with an insulated attic or roof - K6 = 0.9;
if there is a heated room on top - K6 = 0.8.

K7 is an indicator that takes into account the type of window blocks. The design of the window significantly affects heat loss. In this case, the value of coefficient K7 is determined as follows:

since double-glazed wooden windows do not sufficiently protect the room, the highest indicator is K7 = 1.27;
double-glazed windows have excellent properties of protection against heat loss; with a single-chamber double-glazed window made of two glasses, K7 is equal to one;
improved single-chamber double-glazed window with argon filling or double-glazed window consisting of three glasses K7 = 0.85.

K8 – coefficient depending on the glazing area of window openings. Heat loss depends on the quantity and area installed windows. The ratio of window area to room area should be adjusted so that the coefficient has the lowest values. Depending on the ratio of the window area to the room area, the required indicator is determined:

less than 0.1 – K8 = 0.8;
from 0.11 to 0.2 – K8 = 0.9;
from 0.21 to 0.3 – K8 = 1.0;
from 0.31 to 0.4 – K8 = 1.1;
from 0.41 to 0.5 – K8 = 1.2.

K9 – takes into account the connection diagram of devices. Depending on the method of connecting hot and cold water, heat transfer depends. This factor must be taken into account when installing and determining the required area of heat supply devices. Taking into account the connection diagram:

with diagonal pipe arrangement, supply hot water is carried out from above, return - from below on the other side of the battery, and the indicator is equal to one;
when connecting the supply and return from one side and from above and below one section K9 = 1.03;
the connection of pipes on both sides implies both supply and return from below, with coefficient K9 = 1.13;
diagonal connection option, when the supply is from below, the return is from above K9 = 1.25;
one-sided connection option with supply from below, return from above and one-sided bottom connection K9 = 1.28.

K10 is a coefficient depending on the degree of covering of devices with decorative panels. The openness of devices for free exchange of heat with the room space is of no small importance, since the creation of artificial barriers reduces the heat transfer of batteries.

Existing or artificially created barriers can significantly reduce the efficiency of the battery due to the deterioration of heat exchange with the room. Depending on these conditions, the coefficient is equal to:

with the radiator open on the wall on all sides 0.9;
if the device is covered from above by the unit;
when the radiators are covered from above the wall niche 1.07;
if the device is covered by a window sill and decorative element 1,12;
when the radiators are completely covered with a decorative casing 1,2.

In addition, there are special regulations for the location of heating devices that must be observed. That is, the battery should be placed on no less than:

10 cm from the bottom of the window sill;
12 cm from the floor;
2 cm from the surface of the outer wall.

By substituting all the necessary indicators, you can obtain a fairly accurate value of the required thermal power of the room. By dividing the results obtained by the passport data of the heat transfer of one section of the selected device and rounding to an integer, we obtain the number of required sections. Now you can, without fear of consequences, select and install the necessary equipment with the required thermal output.

Ways to simplify calculations

Despite the apparent simplicity of the formula, in reality the practical calculation is not so simple, especially if the number of rooms being calculated is large. The use of special calculators posted on the websites of some manufacturers will help simplify the calculations. It is enough to enter all the necessary data in the appropriate fields, after which you can get the exact result. You can also use the tabular method, since the calculation algorithm is quite simple and uniform.

06/25/2019 at 16:49

When designing heating systems, a mandatory step is to calculate the power of heating devices. The result obtained largely influences the choice of one or another equipment - heating radiators and heating boilers (if the project is carried out for private houses not connected to central heating systems).

The most popular batteries at the moment are those made in the form of interconnected sections. In this article we will talk about how to calculate the number of radiator sections.

Methods for calculating the number of battery sections

In order to calculate the number of sections of heating radiators, you can use three main methods. The first two are quite easy, but they give only an approximate result, which is suitable for typical premises multi-storey buildings. This includes the calculation of radiator sections by room area or volume. Those. in this case, it is enough to find out the required parameter (area or volume) of the room and insert it into the appropriate formula for calculation.

The third method involves the use of many different coefficients for calculations that determine the heat loss of the room. This includes the size and type of windows, floor, type of wall insulation, ceiling height and other criteria that affect heat loss. Heat loss can also occur for various reasons related to errors and shortcomings during the construction of a house. For example, there is a cavity inside the walls, the insulation layer has cracks, defects in the building material, etc. Thus, searching for all the causes of heat leakage is one of the mandatory conditions to perform an accurate calculation. For this purpose, thermal imagers are used, which display on the monitor the places of heat leakage from the room.

All this is done in order to select a radiator power that compensates for the total heat loss. Let's consider each method of calculating battery sections separately and give a clear example for each of them.

Calculation of the number of heating radiator sections by room volume calculator. Number of radiator sections

Section (heating radiator) is the smallest structural element of a heating radiator battery.

Usually it is a hollow cast iron or aluminum double-tube structure, finned to improve thermal transfer by radiation and convection.

The sections of the heating radiator are connected to each other into batteries using radiator nipples, the supply and removal of coolant (steam or hot water) is made through screwed couplings, excess (unused) holes are plugged with threaded plugs into which a valve is sometimes screwed in to drain air from the heating system. The assembled battery is usually painted after assembly.

Calculator for the number of sections in heating radiators

Power of 1 section (W)

Room length

Room width

Thermal insulation of walls

High-quality modern insulation Brick (2 bricks) or insulation Poor insulation

Online calculator for calculating the required number of radiator sections for heating a given room with a known heat transfer

Formula for calculating the number of radiator sections

N = S/t*100*w*h*r

N - number of radiator sections;
S is the area of the room;
t is the amount of heat to heat the room;

The required amount to heat a room (t) is calculated by multiplying the area of the room by 100 W. That is, to heat a room of 18 m2, you need 18*100=1800 W or 1.8 kW of heat

Synonyms: radiator, heating, heat, battery, sections of the radiator, radiator.

Calculation of the number of sections of cast iron heating radiators by room volume. How to calculate the number of radiators

Calculating the number of heating radiators can be done in three ways:

Determining the required heating system based on the area of the heated room.
Calculation of the required radiator sections based on the volume of the room.
The most complex, but at the same time the most accurate calculation method, which takes into account the maximum number of factors influencing the creation of a comfortable temperature in the room.

Before dwelling on the above calculation methods, we cannot ignore the radiators themselves. Their ability to transfer the thermal energy of the carrier to the environment, as well as power, depends on the material from which they are made. In addition, radiators differ in durability (ability to resist corrosion), have different maximum permissible operating pressure and weight.

Since the battery consists of a set of sections, it is necessary to take into account the types of materials from which radiators are made and to know their positive and negative qualities. The material chosen will determine how many battery sections will need to be installed. Now we can distinguish 4 types of heating radiators on the market. These are cast iron, aluminum, steel and bimetallic structures.

Cast iron radiators perfectly accumulate heat, withstand high pressure and have no restrictions on the type of coolant. But at the same time, they are heavy and require special attention to fastening. Steel radiators have less weight compared to cast iron, operate at any pressure and are the most budget option, but their heat transfer coefficient is lower than that of all other batteries.

Aluminum radiators give off heat well, they are lightweight, have a reasonable price, but do not withstand high pressure in the heating network. Bimetallic radiators take the best from steel and aluminum radiators, but have the highest price among the options presented.

It is believed that the power of one section of a cast iron battery is 145 W, aluminum - 190 W, bimetallic - 185 W and steel - 85 W.

The way in which the structure is connected to the heating network is of great importance. The calculation of the power of heating radiators directly depends on the methods of supply and removal of coolant, and this factor also affects the number of heating radiator sections required for normal heating of a given room.

Video Calculation of heating radiators Part 1

A simple calculation does not take into account many factors. The result is distorted data. Then some rooms remain cold, others too hot. The temperature can be controlled using shut-off valves, but it is better to accurately calculate everything in advance in order to use the right amount of materials.

For accurate calculations, decreasing and increasing thermal coefficients are used. First you should pay attention to the windows. For single glazing, a coefficient of 1.7 is used. Double windows do not require a factor. For triples the figure is 0.85.

If the windows are single and there is no thermal insulation, then the heat loss will be quite large.

When calculating, take into account the ratio of the area of floors and windows. The ideal ratio is 30%. Then a coefficient of 1 is applied. When the ratio increases by 10%, the coefficient increases by 0.1.

Coefficients for different ceiling heights:

If the ceiling is below 2.7 m, the coefficient is not needed;
For indicators from 2.7 to 3.5 m, a coefficient of 1.1 is used;
When the height is 3.5-4.5 m, a coefficient of 1.2 will be required.

In the presence of attics or upper floors, certain coefficients are also applied. For a warm attic, an indicator of 0.9 is used, for a living room - 0.8. For unheated attics take 1.

The easiest way. Calculate the amount of heat required for heating, based on the area of the room in which the radiators will be installed. You know the area of each room, and the heat requirement can be determined according to SNiP building codes:

for the average climate zone, 60-100 W are required for heating 1 m 2 of living space;
for areas above 60 o, 150-200 W are required.

Based on these standards, you can calculate how much heat your room will require. If the apartment/house is located in the middle climate zone, heating an area of 16 m2 will require 1600 W of heat (16*100=1600). Since the standards are average, and the weather is not constant, we believe that 100W is required. Although, if you live in the south of the middle climate zone and your winters are mild, count 60W.

Calculation of heating radiators can be done according to SNiP standards

A power reserve in heating is needed, but not very large: with an increase in the amount of power required, the number of radiators increases. And the more radiators, the more coolant in the system. If for those who are connected to central heating this is not critical, then for those who have or plan to individual heating, a large volume of the system means large (extra) costs for heating the coolant and greater inertia of the system (the set temperature is maintained less accurately). And a logical question arises: “Why pay more?”

Having calculated the room's heat requirement, we can find out how many sections are required. Each heating device can produce a certain amount of heat, which is indicated in the passport. Take the found heat requirement and divide it by the radiator power. The result is the required number of sections to make up for losses.

Let's count the number of radiators for the same room. We determined that 1600W needed to be allocated. Let the power of one section be 170W. It turns out 1600/170 = 9.411 pieces. You can round up or down at your discretion. You can round it to a smaller one, for example, in the kitchen - there are enough additional heat sources there, and to a larger one - it is better in a room with a balcony, a large window or in a corner room.

The system is simple, but the disadvantages are obvious: ceiling heights can be different, wall material, windows, insulation and a number of other factors are not taken into account. So the calculation of the number of sections of heating radiators according to SNiP is approximate. For an accurate result, you need to make adjustments.

Calculation of the number of sections of heating radiators by area calculator. Selection of heating power

When selecting a heating scheme for a small private house, it is this indicator that is decisive.

To calculate sections bimetallic radiators heating by area, you need to determine the following parameters:

the amount of necessary compensation for heat losses;
total area of the heated room.

In construction practice, it is customary to use the first indicator in the given form as 1 kW of power per 10 square meters, i.e. 100 W/m2. Thus, the ratio for calculation will be the following expression:

N = S x 100 x 1.45,

where S is the total area of the heated room, 1.45 is the coefficient of possible heat loss.

If we look at a specific example of calculating the heating power for a room of 4x5 meters, it will look like this:

5 x 4 = 20 (m2);

A typical place to install a radiator is under a window, so we use two radiators of the same power of 1450 W. This indicator can be influenced by adding or reducing the number of sections installed in the battery. It should be taken into account that the power of one of them is:

for bimetallic ones with a height of 50 centimeters - 180 watts;
for cast iron radiators – 130 watts.

Therefore, you will need to install: bimetallic - 1450: 180 = 8 x2 = 16 sections; cast iron: 1450: 130 = 11.

When using glass bags, heat loss on windows can be reduced by approximately 25%.

Calculation of sections of bimetallic heating radiators by area gives a clear initial idea of their required quantity.

To determine the volume of a room, you will have to use indicators such as ceiling height, width and length. Having multiplied all the parameters and obtained the volume, it should be multiplied by the power indicator determined by SNiP in the amount of 41 W.

For example, the room area (width x length) is 16 m2, and the ceiling height is 2.7 m, which gives a volume (16x2.7) equal to 43 m3.

To determine the power of the radiator, the volume should be multiplied by the power indicator:

After this, the result obtained is also divided by the power of one radiator section. For example, it is equal to 160 W, which means that for a room with a volume of 43 m3, 11 sections will be required (1771: 160).

And such a calculation of bimetallic heating radiators per square meter will also not be accurate. To make sure how many sections in the battery are actually required, you need to make calculations using a more complex but accurate formula that takes into account all the nuances, right down to the air temperature outside the window.

This formula looks like this:

S x 100 x k1 x k2 x k3 x k4 x k5 x k6 * k7 = radiator power, where K is the heat loss parameters:

k1 – glazing type;

k2 – quality of wall insulation;

k3 – window size;

k4 – outside temperature;

k5 – external walls;

k6 is the room above the room;

k7 – ceiling height.

If you are not too lazy and calculate all these parameters, you can get the actual number of sections of a bimetallic radiator per 1 m2.

It’s not difficult to make such calculations, and even an approximate figure is better than buying a battery at random.

Bimetallic radiators are expensive and high-quality products, so before purchasing and installing, you should carefully familiarize yourself with not only such parameters as thermal power and resistance to high pressures, but also with their device.

Each manufacturer has its own attractive features for customers. You can't buy batteries just for the sake of promotions. A high-quality calculation of the thermal power of a bimetallic radiator will provide the room with heat for the next 20 - 30 years, which is much more attractive than a one-time discount.

Table for calculating the required number of sections depending on the area of the heated room and the power of one section.

Calculating the number of sections of heating batteries using a calculator gives good results. Let's give a simple example for heating a room of 10 square meters. m - if the room is not corner and has double glazed windows, the required thermal power will be 1000 W. If we want to install aluminum batteries with a heat dissipation of 180 W, we will need 6 sections - we simply divide the resulting power by the heat dissipation of one section.

Accordingly, if you buy radiators with a heat output of one section of 200 W, then the number of sections will be 5 pieces. Will the room have high ceilings up to 3.5 m? Then the number of sections will increase to 6 pieces. Does the room have two external walls (corner room)? In this case, you need to add another section.

You also need to take into account the thermal power reserve in case of a too cold winter - it is 10-20% of the calculated one.

You can find out information about the heat transfer of batteries from their passport data. For example, the number of sections of aluminum heating radiators is calculated based on the heat transfer of one section. The same applies to bimetallic radiators (and cast iron ones, although they are not removable). When using steel radiators, the rated power of the entire device is taken (we gave examples above).

Calculation of heating radiators in a private house. Calculation of the number of radiators in a private house

If for apartments it is possible to take the average parameters of heat consumption, since they are designed for standard room dimensions, then in private construction this is incorrect. After all, many owners build their houses with ceiling heights exceeding 2.8 meters, in addition, almost all private premises are corner, so heating them will require more power. In this case, calculations based on the area of the room are not suitable: you need apply the formula taking into account the volume of the room and make adjustments by applying coefficients for reducing or increasing heat transfer. The values of the coefficients are as follows:

0.2 - the resulting final power number is multiplied by this indicator if multi-chamber plastic double-glazed windows are installed in the house.
1.15 – if the boiler installed in the house operates at its capacity limit. In this case, every 10 degrees of heated coolant reduces the power of the radiators by 15%.
1.8 is the magnification factor that needs to be applied if the room is corner and has more than one window.

To calculate the power of radiators in a private house, the following formula is used:

P = V x 41, where

V – volume of the room;
41 – average power required to heat 1 sq. m of a private house.

Calculation example If you have a room of 20 sq. m (4x5 m - the length of the walls) with a ceiling height of 3 meters, then its volume is easy to calculate: 20 x 3 = 60 W. The resulting value is multiplied by the power accepted by the standards: 60 x 41 = 2460 W - this is how much heat is required to heat the area in question. Calculation of the number of radiators comes down to the following (taking into account that one radiator section emits 160 W on average, and their exact data depends on the material from which the batteries are made): 2460 / 160 = 15.4 pieces. Let's assume that a total of 16 sections are needed, then There is a need to purchase 4 radiators of 4 sections for each wall or 2 of 8 sections. At the same time, one should not forget about the adjustment coefficients.

Types of steel heating radiators

Let's consider panel-type steel radiators, which vary in size and power level. Devices can consist of one, two or three panels. Another important design element is fins (corrugated metal plates). To achieve certain thermal output values, several combinations of panels and fins are used in the design of the devices. Before choosing the most suitable device for high-quality room heating, you need to familiarize yourself with each type.

Main types of steel radiators

Steel panel batteries are available in the following types:

Type 10. Here the device is equipped with only one panel. Such radiators are light in weight and have the lowest power.

Steel heating radiators type 10

Type 11. Consists of one panel and a fin plate. The batteries are slightly heavier and larger than the previous type, and have higher thermal power parameters.

Steel panel radiator type 11

Type 21. The radiator has two panels, between which there is a corrugated metal plate.
Type 22. The battery consists of two panels, as well as two fin plates. The device is similar in size to type 21 radiators, however, compared to them, they have greater thermal power.

Steel panel radiator type 22

Type 33. The design consists of three panels. This class is the most powerful in terms of thermal output and the largest in size. In its design, 3 fin plates are attached to three panels (hence the type number - 33).

Steel panel radiator type 33

Each of the presented types may vary in the length of the device and its height. Based on these indicators, the thermal power of the device is formed. It is impossible to calculate this parameter independently. However, each model of panel radiator undergoes appropriate testing by the manufacturer, so all results are entered into special tables. Using them, it is very convenient to choose a suitable battery for heating various types of premises.

When installing and replacing heating radiators, the question usually arises: how to correctly calculate the number of sections of heating radiators so that the apartment is cozy and warm even in the coldest time of the year? It’s not difficult to do the calculation yourself; you just need to know the parameters of the room and the power of the batteries of the selected type. For corner rooms and rooms with ceilings higher than 3 meters or panoramic windows, the calculation is slightly different. Let's consider all calculation methods.

Rooms with standard ceiling heights

The number of heating radiator sections for a typical house is calculated based on the area of the rooms. The area of a room in a typical house is calculated by multiplying the length of the room by its width. To heat 1 square meter, 100 W of heating device power is required, and to calculate the total power, you need to multiply the resulting area by 100 W. The resulting value means the total power of the heating device. The documentation for the radiator usually indicates the thermal power of one section. To determine the number of sections, you need to divide the total power by this value and round the result up.

Calculation example:

A room with a width of 3.5 meters and a length of 4 meters, with a normal ceiling height. The power of one radiator section is 160 W. You need to find the number of sections.

We determine the area of the room by multiplying its length by its width: 3.5·4 = 14 m2.
We find the total power of heating devices 14·100 = 1400 W.
Find the number of sections: 1400/160 = 8.75. We round up to a higher value and get 9 sections.

For rooms located at the end of the building, the estimated number of radiators must be increased by 20%.

Rooms with a ceiling height of more than 3 meters

The number of heating sections for rooms with a ceiling height of more than three meters is calculated based on the volume of the room. Volume is the area multiplied by the height of the ceilings. For heating 1 cubic meter the room requires 40 W of the thermal power of the heating device, and its total power is calculated by multiplying the volume of the room by 40 W. To determine the number of sections, this value must be divided by the capacity of one section according to the passport.

Calculation example:

A room with a width of 3.5 meters and a length of 4 meters, with a ceiling height of 3.5 m. The power of one radiator section is 160 W. It is necessary to find the number of sections of heating radiators.

You can also use the table:

As in the previous case, for a corner room this figure must be multiplied by 1.2. It is also necessary to increase the number of sections if the room has one of the following factors:

Located in a panel or poorly insulated house;
Located on the first or last floor;
Has more than one window;
Located next to unheated rooms.

In this case, the resulting value must be multiplied by a factor of 1.1 for each factor.

Calculation example:

Corner room with a width of 3.5 meters and a length of 4 meters, with a ceiling height of 3.5 m. Located in panel house, on the ground floor, has two windows. The power of one radiator section is 160 W. It is necessary to find the number of sections of heating radiators.

Find the area of the room by multiplying its length by its width: 3.5·4 = 14 m2.
We find the volume of the room by multiplying the area by the height of the ceilings: 14·3.5 = 49 m3.
We find the total power of the heating radiator: 49·40 = 1960 W.
Find the number of sections: 1960/160 = 12.25. Round up and get 13 sections.
We multiply the resulting amount by the coefficients:

Corner room - coefficient 1.2;

Panel house – coefficient 1.1;

Two windows - coefficient 1.1;

First floor - coefficient 1.1.

Thus, we get: 13·1.2·1.1·1.1·1.1 = 20.76 sections. We round them up to a larger integer - 21 sections of heating radiators.

When making calculations, it should be borne in mind that different types of heating radiators have different thermal output. When choosing the number of heating radiator sections, you must use exactly those values that correspond.

In order for the heat transfer from radiators to be maximum, it is necessary to install them in accordance with the manufacturer’s recommendations, observing all the distances specified in the passport. This promotes better distribution of convective flows and reduces heat loss.

During the cold season, heating is the most important communication system, which is responsible for comfortable living in the house. Heating radiators are part of this system. The overall temperature of the room will depend on their number and area. Therefore, correctly calculating the number of radiator sections is the key to efficient operation of the entire system, plus saving on fuel used to heat the coolant.

In this article:

What you need for independent calculations

Things to consider:

the size of the rooms where they will be installed;
number of windows and entrance doors, their area;
the materials from which the house is built (in this case, the walls, floor and ceiling are taken into account);
location of the room relative to the cardinal directions;
technical parameters of the heating device.

If you are not a specialist, it will be very difficult to carry out calculations on your own using all the listed criteria. Therefore, many private developers use a simplified methodology that allows you to calculate only the approximate number of radiators for a room.

If you want to make accurate calculations, use calculation calculations according to SNiP.

Calculation method according to SNiP

Table of approximate calculations

SNiP stipulates that best option the required number of radiator sections depends on the thermal energy they emit. It should be equal to 100 W per 1 m² of room area.

The formula used for calculation is: N=Sx100/P

N is the number of battery sections;
S – room area;
P – section power (this indicator can be viewed in the product data sheet).

But since additional indicators must be taken into account in the calculation, new variables are added to the formula.

Amendments to the formula

If the house has plastic windows, you can reduce the number of sections by 10%. That is, a coefficient of 0.9 is added for calculation.
If ceiling height is 2.5 meters, a coefficient of 1.0 is applied. If the ceiling height is greater, then the coefficient increases to 1.1-1.3
The number and thickness of external walls also affects this parameter: the thicker the walls, the lower the coefficient.
The number of windows also affects heat loss. Each window adds 5% to the coefficient.
If there is a heated attic or attic above the room, the number of sections can be reduced specifically in this room.
Corner room or room with balcony add an additional 1.2 coefficients to the formula.
Batteries hidden in a niche and covered with a decorative screen add 15% to the final figure.

Using additional adjustments, you will find out how many sections you need to put in each room. And you can easily find out how many radiators you need per square meter.

How to calculate the number of sections: example on cast iron batteries

Let's calculate how many cast iron radiator sections need to be installed in a room with two two-chamber plastic windows with a ceiling height of 2.7 m, the area of which is 22 m².

Mathematical formula: (22x100/145)x1.05x1.1x0.9=15.77

We round the resulting number to a whole number - we get 16 sections: two batteries for each window, 8 sections each.

Explanation of odds:

1.05 is a five percent surcharge for the second window;
1.1 is an increase in ceiling height;
0.9 is a reduction for installing plastic windows.

Let's be honest - this option, as noted above, is difficult for the average consumer. But there are simplified methods, which will be discussed below.

Influence of material on the number of sections

Developers often face a question in the context of the material from which they are made. After all, steel, cast iron, copper, aluminum have their own heat transfer rate, and this also must be taken into account when making calculations.

As mentioned above, this parameter can be found in the product passport.

For example:

The cast iron radiator has a heat output of 145 W.
Aluminum – 190 W.
Bimetallic – 185 W.

From this list we can conclude that the number of aluminum sections will be used less than, say, cast iron. And more than bimetallic ones. And this is with all the other parameters mentioned above being the same.

Calculation by room area

The same formula is used here - N=Sx100/P, with one caveat: ceiling height should not exceed 2.6 m.

We will use the parameters that were taken into account in the example with a cast iron battery, but we will make some changes regarding the number of windows.

To simplify the example, let’s take just one window: 22x100/145=15.17

You can round down to 15 sections, but keep in mind that the missing section can reduce the temperature by a couple of degrees, which will lead to an overall decrease in the comfort of being in the room.

Calculation by room volume

In this case The main indicator is thermal energy, equal to 41 W per 1 m³. This is also a standard value. True, in rooms with double-glazed windows, a value equal to 34 W is used.

22x2.6x41/145=16.17 – round up, resulting in 16 sections.

Pay attention to one very subtle nuance.

Manufacturers, when indicating the heat transfer value in the product data sheet, take it into account according to the maximum parameter. In other words, they believe that the hot water temperature in the system will be at its maximum. In life this is not always true. Therefore, we strongly recommend rounding the final result up.

And if the power of the section is determined by the manufacturer in a certain range (a fork is installed between two indicators), then choose a lower indicator for calculations.

Calculation by eye

Heat loss in an apartment building

This option is suitable for those who know absolutely nothing about mathematical calculations. Divide the area of the room by the standard indicator - 1 section per 1.8 m².

22/1.8=12.22 – round up, resulting in 13 sections.

Keep in mind: the ceiling height should not exceed 2.7 m. If the ceiling is higher, you will have to calculate using a more complex formula.

As you can see, there are different ways to calculate the required number of sections for a room. If you want to get an accurate result, use the calculation according to SNiP. If you can’t decide on additional coefficients, choose any other simplified option.

One of the main goals of preparatory activities before installing a heating system is to determine how many heating devices will be needed in each room, and what power they should have. Before calculating the number of radiators, it is recommended that you familiarize yourself with the basic techniques of this procedure.

Calculation of heating radiator sections by area

This is the simplest type of calculation of the number of sections of heating radiators, where the volume of heat required to heat the room is determined based on the square meters of the home.

The average climate zone requires 60-100 W to heat 1 m2 of housing.
For northern regions, this norm corresponds to 150-200 W.

With these numbers in hand, the required heat is calculated. For example, for middle-class apartments, heating a room with an area of 15 m2 will require 1500 W of heat (15x100). It should be understood that we are talking about average standards, so it is better to focus on the maximum indicators for a particular region. For areas with very mild winters, a coefficient of 60 W can be used.

When making a power reserve, it is advisable not to overdo it, as this will require the use of a large number of heating devices. Consequently, the volume of required coolant will also increase. For residents of apartment buildings with central heating this question is not fundamental. Residents of the private sector have to increase the cost of heating the coolant, against the backdrop of increasing inertia of the entire circuit. This implies the need for careful calculation of heating radiators by area.

After determining all the heat needed for heating, it becomes possible to find out the number of sections. The accompanying documentation for any heating device contains information about the heat it produces. To calculate the sections, the total volume of heat required must be divided by the battery power. To see how this happens, you can refer to the example already given above, where, as a result of the calculations, the required volume for heating a room of 15 m2 was determined - 1500 W.

Let’s take the power of one section as 160 W: it turns out that the number of sections will be 1500:160 = 9.375. In which direction to round is the user's choice. Usually, the presence of indirect sources of heating the room and the degree of its insulation are taken into account. For example, in the kitchen the air is also heated by household appliances during cooking, so you can round down there.

The method for calculating sections of heating radiators by area is characterized by considerable simplicity, however, a number of serious factors will disappear from view. These include the height of the premises, the number of door and window openings, the level of wall insulation, etc. Therefore, the method of calculating the number of radiator sections according to SNiP can be called approximate: in order to get a result without errors, you cannot do without corrections.

Room volume

This calculation approach also involves taking into account the height of the ceilings, because The entire volume of air in the home is subject to heating.

The calculation method used is very similar - first the volume is determined, after which the following standards are used:

For panel houses, heating 1 m3 of air requires 41 W.
A brick house requires 34 W/m3.

For clarity, you can calculate the heating radiators of the same room of 15 m2 to compare the results. Let’s take the height of the home to be 2.7 m: in the end the volume will be 15x2.7 = 40.5.

Calculation for different buildings:

Panel house. To determine the heat required for heating, 40.5 m3x41 W = 1660.5 W. To calculate the required number of sections 1660.5:170 = 9.76 (10 pcs.).
Brick house. The total volume of heat is 40.5 m3x34 W = 1377 W. Radiator count – 1377:170 = 8.1 (8 pcs.).

It turns out that significantly fewer sections will be required to heat a brick house. When the calculation of radiator sections per area was carried out, the result was averaged - 9 pieces.

We adjust the indicators

To more successfully solve the question of how to calculate the number of radiators per room, it is necessary to take into account some additional factors that contribute to an increase or decrease in heat loss. The material used to make the walls and the level of their thermal insulation have a significant influence. The number and size of windows, the type of glazing used for them, external walls, etc. also play a significant role. To simplify the procedure for calculating a radiator for a room, special coefficients are introduced.

Window

Approximately 15-35% of heat is lost through window openings: this is influenced by the size of the windows and the degree of their insulation. This explains the presence of two coefficients.

Window to floor area ratio:

10% - 0,8
20% - 0,9
30% - 1,0
40% - 1,1
50% - 1,2

By type of glazing:

3-chamber double-glazed windows or 2-chamber double-glazed windows with argon - 0.85;
standard 2-chamber double-glazed window - 1.0;
simple double frames - 1.27.

Walls and roof

When performing an accurate calculation of heating radiators per area, one cannot do without taking into account the material of the walls and the degree of their thermal insulation. There are also coefficients for this.

Insulation level:

They take the norm brick walls in two bricks - 1.0.
Small (absent) - 1.27.
Good - 0.8.

External walls:

Not available - no losses, coefficient 1.0.
1 wall - 1.1.
2 walls - 1.2.
3 walls - 1.3.

The level of heat loss is closely related to the presence or absence of a residential attic or second floor. If such a room exists, the coefficient will be reducing 0.7 (for a heated attic - 0.9). As a given, it is assumed that the degree of influence on the room temperature of a non-residential attic is neutral (coefficient 1.0).

In situations where, when calculating sections of heating radiators by area, one has to deal with a non-standard ceiling height (2.7 m is considered the standard), decreasing or increasing factors are applied. To obtain them, the existing height is divided by the standard 2.7 m. Let's take an example with a ceiling height of 3 m: 3.0 m/2.7 m = 1.1. Next, the indicator obtained when calculating radiator sections by room area is raised to the power of 1.1.

When determining the above norms and coefficients, apartments were taken as a guideline. To find out the level of heat loss in a private house from the roof and basement, another 50% is added to the result. Thus, this coefficient will be equal to 1.5.

Climate

There is also an adjustment for average winter temperatures:

10 degrees and above - 0.7
-15 degrees - 0.9
-20 degrees - 1.1
-25 degrees - 1.3
-30 degrees - 1.5

After making all possible adjustments to the calculation of aluminum radiators by area, a more objective result is obtained. However, the above list of factors will not be complete without mentioning the criteria that affect the heating power.

Radiator type

If the heating system is equipped with sectional radiators, in which the axial distance has a height of 50 cm, then calculating the sections of heating radiators will not cause any particular difficulties. As a rule, reputable manufacturers have their own websites indicating the technical data (including thermal power) of all models. Sometimes, instead of power, coolant consumption may be indicated: converting it into power is very simple, because coolant consumption of 1 l/min corresponds to approximately 1 kW. To determine the axial distance, it is necessary to measure the distance between the centers of the supply pipe to the return pipe.

To make the task easier, many sites are equipped with a special calculation program. All that is needed to calculate batteries for a room is to enter its parameters in the specified lines. By pressing the “Enter” field, the number of sections of the selected model is instantly displayed at the output. When deciding on the type of heating device, take into account the difference in the thermal power of the heating radiator by area, depending on the material of manufacture (all other things being equal).

The simplest example of calculating sections of a bimetallic radiator, where only the area of the room is taken into account, will make it easier to understand the essence of the issue. When deciding on the number of bimetallic heating elements with a standard center distance of 50 cm, the starting point is the possibility of heating 1.8 m2 of a home in one section. In this case, for a room of 15 m2 you will need 15: 1.8 = 8.3 pcs. After rounding we get 8 pieces. Batteries made of cast iron and steel are calculated in a similar way.

This will require the following coefficients:

For bimetallic radiators - 1.8 m2.
For aluminum - 1.9-2.0 m2.
For cast iron - 1.4-1.5 m2.

These parameters are suitable for a standard center-to-center distance of 50 cm. Currently, radiators are produced where this distance can range from 20 to 60 cm. There are even so-called “curb” models with a height of less than 20 cm. It is clear that the power of these batteries will be different, which will require making certain adjustments. Sometimes this information is indicated in the accompanying documentation, in other cases you will need to calculate it yourself.

Considering that the heating surface area directly affects the thermal power of the device, it is easy to guess that as the height of the radiator decreases, this figure will fall. Therefore, the correction factor is determined by relating the height of the selected product to the standard of 50 cm.

For example, let's calculate an aluminum radiator. For a room of 15 m2, the calculation of heating radiator sections based on the area of the room gives the result 15:2 = 7.5 pieces. (rounded up to 8 pcs.) It was planned to use small-sized devices with a height of 40 cm. First you need to find the ratio 50:40 = 1.25. After adjusting the number of sections, the result is 8x1.25 = 10 pcs.

Taking into account the heating system mode

The accompanying documentation for the radiator usually contains information about its maximum power. If a high-temperature operating mode is used, then in the supply pipe the coolant heats up to +90 degrees, and in the return pipe - +70 degrees (marked 90/70). The temperature of the home should be +20 degrees. Similar mode of operation modern systems heating is practically not used. Medium (75/65/20) or low (55/45/20) power is more common. This fact requires adjustments to the calculation of the power of heating batteries by area.

To determine the operating mode of the circuit, the temperature difference of the system is taken into account: this is the name for the difference in temperature between the air and the surface of the radiator. The temperature of the heating device is taken as the arithmetic mean between the flow and return values.

For a better understanding, let's calculate cast iron batteries with standard sections of 50 cm in high and low temperature modes. The area of the room is the same - 15 m2. Heating of one cast iron section in high temperature mode is provided for 1.5 m2, so the total number of sections will be 15: 1.5 = 10. The use of low temperature mode is planned in the circuit.

Determination of the temperature pressure of each mode:

High temperature - 90/70/20- (90+70):20 =60 degrees;
Low temperature - 55/45/20 - (55+45):2-20 = 30 degrees.

It turns out that to ensure normal heating of the room at low temperatures, the number of radiator sections needs to be doubled. In our case, for a room of 15 m2, 20 sections are needed: this assumes the presence of a fairly wide cast-iron battery. This is why cast iron appliances are not recommended for use in low-temperature systems.

The desired air temperature can also be taken into account. If the goal is to raise it from 20 to 25 degrees, the thermal pressure is calculated with this amendment, calculating the required coefficient. Let's calculate the power of heating batteries based on the area of the same cast-iron radiator, introducing adjustments to the parameters (90/70/25). The calculation of the temperature difference in this situation will look like this: (90+70):2-25=55 degrees. Now we calculate the ratio 60:55 = 1.1. To ensure a temperature of 25 degrees, you need 11 pieces x1.1=12.1 radiators.

Influence of installation type and location

Along with the factors already mentioned, the degree of heat transfer from the heating device also depends on how it was connected. The most effective is considered to be diagonal switching with supply from above, which reduces the level of heat loss to almost zero. The greatest losses of thermal energy are demonstrated by the lateral connection - almost 22%. The remaining types of installation are characterized by average efficiency.

Various blocking elements also help reduce the actual power of the battery: for example, a window sill hanging from above reduces heat transfer by almost 8%. If the radiator is not completely blocked, losses are reduced to 3-5%. Partially covered decorative mesh screens provoke a drop in heat transfer at the level of the overhanging window sill (7-8%). If the battery is completely covered with such a screen, its efficiency will decrease by 20-25%.

How to calculate the number of radiators for a single-pipe circuit

It should be taken into account that all of the above applies to two-pipe heating circuits, which require the same temperature to be supplied to each radiator. Calculating sections of a heating radiator in a single-pipe system is much more difficult, because each subsequent battery in the direction of movement of the coolant is heated an order of magnitude less. Therefore, the calculation for a single-pipe circuit requires constant revision of the temperature: such a procedure takes a lot of time and effort.

To simplify the procedure, a technique is used when the calculation of heating per square meter is carried out as for a two-pipe system, and then, taking into account the drop in thermal power, sections are increased to increase the heat transfer of the circuit in general. For example, let's take a single-pipe type circuit that has 6 radiators. After determining the number of sections, as for a two-pipe network, we make certain adjustments.

The first of the heating devices in the direction of movement of the coolant is provided with fully heated coolant, so it does not need to be recalculated. The supply temperature to the second device is already lower, so you need to determine the degree of power reduction by increasing the number of sections by the resulting value: 15 kW-3 kW = 12 kW (the percentage of temperature reduction is 20%). So, to replenish heat losses, additional sections will be needed - if at first 8 pieces were needed, then after adding 20% we get the final number - 9 or 10 pieces.

When choosing which direction to round, take into account the functional purpose of the room. If we are talking about a bedroom or a nursery, rounding is carried out upward. When calculating the living room or kitchen, it is better to round down. It also has its share of influence on which side the room is located - southern or northern (northern rooms are usually rounded up, and southern ones - down).

This calculation method is not perfect, as it involves enlarging the last radiator on the line to truly gigantic proportions. It should also be understood that the specific heat capacity of the supplied coolant is almost never equal to its power. Because of this, boilers for equipping single-pipe circuits are selected with some reserve. The situation is optimized by the presence of shut-off valves and switching of batteries through a bypass: thanks to this, it is possible to adjust the heat transfer, which somewhat compensates for the decrease in coolant temperature. However, even these techniques do not free you from the need to increase the size of radiators and the number of its sections as you move away from the boiler when using a single-pipe circuit.

To solve the problem of how to calculate heating radiators by area, you won’t need a lot of time and effort. Another thing is to correct the result obtained, taking into account all the characteristics of the home, its size, switching method and location of radiators: this procedure is quite labor-intensive and time-consuming. However, this is how you can obtain the most accurate parameters for the heating system, which will ensure the warmth and comfort of the premises.