How to calculate the number of heating radiators per room. Calculation of sections of heating batteries by area

How to calculate heating radiators in an apartment? How many sections will be the minimum required with a known area of ​​the room?

About simple and relatively complex methods of calculation - this article.

Put aside the gas wrench and the grinder. Today our tool is a calculator.

Disclaimer

This article is not aimed at heating engineers, but at the owners of an apartment or a private house who are going to assemble a heating system with their own hands. If so, the calculation instructions should be simple and straightforward.

We will not use complex formulas and concepts such as "heat flow" and "thermal resistance of walls", trying to simplify the calculations as much as possible.

General Provisions

Any simple calculation method has a rather large error. However, from the practical point of view, it is important for us to ensure a guaranteed sufficient heat output. If it turns out to be more necessary even at the peak of the winter cold, so what?

In an apartment where heating is paid for by area, the heat of the bones does not ache; and regulating throttles and thermostatic temperature controllers are not something very rare and inaccessible.

In the case of a private house and a private boiler, the price of a kilowatt of heat is well known to us, and it would seem that excess heating will hit your pocket. However, in practice this is not the case. All modern gas and are equipped with thermostats that regulate heat transfer depending on the temperature in the room.

Even if our calculation of the power of heating radiators gives a significant error in a big way, we risk only the cost of a few additional sections.

By the way: in addition to the average winter temperatures, extreme frosts occur every few years.
There is a suspicion that due to global climatic changes, they will happen more and more often, so when calculating heating radiators, do not be afraid to make a big mistake.

How to calculate the heat output of a heater

• For all electric heating devices, without exception, the effective thermal power is exactly equal to their rated electrical power.
  Remember the school physics course: if useful work is not done (that is, the movement of an object with a nonzero mass against the gravity vector), all the energy spent goes to heating the environment.

• For most heating devices from decent manufacturers, their thermal power is indicated in the accompanying documentation or on the manufacturer's website.
  Often there you can even find a calculator for calculating heating radiators for a certain volume of a room and parameters of the heating system.

There is one subtlety here: almost always the manufacturer calculates the heat transfer of the radiator - heating batteries, convector or fan coil - for a very specific temperature difference between the coolant and the room, equal to 70C. For Russian realities, such parameters are often an unattainable ideal.

Finally, a simple, albeit approximate, calculation of the power of a heating radiator by the number of sections is possible.

Bimetal radiators

The calculation of bimetallic heating radiators is based on the overall dimensions of the section.

Let's take data from the site of the Bolshevik plant:

• For a section with a center-to-center distance of the connections of 500 millimeters, the heat transfer is 165 watts.
• For the 400mm section, 143 watts.
• 300 mm - 120 watts.
• 250 mm - 102 watts.

Aluminum radiators

Calculation of aluminum radiators is based on the following values ​​(data for Italian radiators Calidor and Solar):

• The section with a center distance of 500 millimeters gives off 178-182 watts of heat.
• With a center-to-center distance of 350 millimeters, the heat transfer of the section decreases to 145-150 watts.

Steel plate radiators

And how to calculate steel plate-type heating radiators? After all, they do not have sections, from the number of which the calculation formula can be based.

Here, the key parameters are, again, the center distance and the length of the radiator. In addition, manufacturers recommend taking into account the method of connecting the radiator: with different methods of inserting into the heating system, the heating and, therefore, the heat output may also differ.

In order not to bore the reader with the abundance of formulas in the text, we will simply refer it to the power table of the Korad radiator range.

Cast iron radiators

And only here everything is extremely simple: all cast-iron radiators produced in Russia have the same center-to-center distance of connections, equal to 500 millimeters, and heat transfer at a standard temperature delta of 70C, equal to 180 watts per section.

Half the job is done. Now we know how to calculate the number of sections or heating devices with a known required heat output. But where do we get the very thermal power that we need?

Calculation of thermal power

We will consider several calculation methods that take into account a different number of variables.

By area

The calculation by area is based on sanitary standards and rules, in which the Russians say in white: one kilowatt of thermal power should fall on 10 m2 of the area of ​​the room (100 watts per m2).

Clarification: the calculation uses a coefficient that depends on the region of the country. For the southern regions it is 0.7 - 0.9, for the Far East - 1.6, for Yakutia and Chukotka - 2.0.

It is clear that the method gives a very significant error:

• Panoramic glazing in one thread will clearly give greater heat loss compared to a solid wall.
• The location of the apartment inside the house is not taken into account, although it is clear that if there are warm walls of neighboring apartments nearby, with the same number of radiators it will be much warmer than in a corner room that has a common wall with the street.
• Finally, the main thing: the calculation is correct for the standard ceiling height in a Soviet-built house, equal to 2.5 - 2.7 meters. However, even at the beginning of the 20th century, houses with a ceiling height of 4 - 4.5 meters were being built, and stalinkas with three-meter ceilings would also require a more accurate calculation.

Let's still apply the method for a 3x4 meter room located in the Krasnodar Territory.

The area is 3x4 = 12 m2.

The required thermal power of heating is 12m2 x100W x0.7 regional coefficient = 840 watts.

With a power of one section of 180 watts, we need 840/180 = 4.66 sections. We will, of course, round the number up - up to five.

Advice: in the conditions of the Krasnodar Territory, a temperature delta between a room and a battery of 70C is unrealistic. It is better to install radiators with at least a 30% margin.

Simple calculation by volume

The calculation for the total volume of air in the room will clearly be more accurate, already because it takes into account the variation in the height of the ceilings. It is also very simple: for 1 m3 of volume, 40 watts of power of the heating system is needed.

Let's calculate the required power for our room near Krasnodar with a slight clarification: it is located in a stalinka built in 1960 with a ceiling height of 3.1 meters.

The volume of the room is 3x4x3.1 = 37.2 cubic meters.

Accordingly, the radiators must have a capacity of 37.2x40 = 1488 watts. Let's take into account the regional coefficient of 0.7: 1488x0.7 = 1041 watts, or six sections of cast-iron fierce horror under the window. Why horror? The appearance and constant leaks between the sections after several years of operation do not cause delight.

If you remember that the price of a cast-iron section is higher than that of an aluminum one, or - the idea of ​​buying such a heater really starts to cause slight panic.

Refined volume calculation

A more accurate calculation of heating systems is carried out taking into account a larger number of variables:

• The number of doors and windows. The average heat loss through a standard size window is 100 watts, through a door 200.
• The location of the room at the end or corner of the house will force us to use a coefficient of 1.1 - 1.3, depending on the material and thickness of the walls of the building.
• For private houses, a coefficient of 1.5 is used, since the heat loss through the floor and roof is much higher. Above and below, after all, not warm apartments, but the street ...

The base value is the same 40 watts per cubic meter and the same regional coefficients as when calculating the area of ​​the room.

Let's calculate the thermal power of heating radiators for a room with the same dimensions as in the previous example, but mentally transfer it to the corner of a private house in Oymyakon (the average January temperature is -54C, at least during the observation period - 82). The situation is aggravated by the door to the street and the window from which the cheerful reindeer herders can be seen.

We have already achieved the basic power, taking into account only the volume of the room: 1488 watts.

The window and door add 300 watts. 1488 + 300 = 1788.

Private house. Cold floor and heat leakage through the roof. 1788x1.5 = 2682.

The angle of the house will force us to apply a factor of 1.3. 2682x1.3 = 3486.6 watts.

Finally, the warm and gentle climate of the Oymyakonsky ulus of Yakutia leads us to the idea that the result obtained can be multiplied by a regional coefficient of 2.0. 6973.2 watts is required to heat a small room!

We are already familiar with the calculation of the number of heating radiators. The total number of cast iron or aluminum sections will be 6973.2 / 180 = 39 rounded sections. With a section length of 93 mm, the accordion under the window will have a length of 3.6 meters, that is, it will barely fit along the longer of the walls ...

“- Ten sections? A good start!" - with such a phrase a resident of Yakutia will comment on this photo.

Conclusion

You will find additional information on the calculation of heating systems in the video at the end of the article. In the end, the author wants to make an official statement: in Oymyakon, of his own free will - not a foot. Warm winters!

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 in a cold season it properly warms up 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, which describe the rules for the design and operation of heating systems in various rooms. But the most clear and simple is the document "Heating, ventilation and air conditioning" under the number 2.04.05.

It details the following sections:

1. General provisions for the design of heating systems
2. Building heating systems design rules
3. Features of the heating system

It is also necessary to install heating radiators in accordance with SNiP under the number 3.05.01... He prescribes the following installation rules, without which the calculations of 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 slight error is allowed - no more than 2 cm)
3. Recommended space between radiators and wall - 2-5 cm
4. Height above the floor should not be more than 12 cm
5. The distance to the windowsill 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 a reflective material.

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

Read also, different types of heating radiators

Volume calculation

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

1. We determine the need for heat
2. Find out the number of sections capable of giving it away

SNiP prescribes to take into account the need for heat 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 are eliminated - this indicator can be taken equal to 30-34 W.

If the room has heating, the heat demand must be increased up to 20%. Part of the heat heated air masses will not be passed by the screen, circulating inside and quickly cooling down.

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

Having decided on the need for one cube, you can start calculating (an example with specific numbers):

1. At the first step, we calculate the volume of the room using a simple formula: [height length Width] (3x4x5 = 60 cubic meters)
2. The next step is to determine the heat demand for a particular room under consideration using the formula: [volume] * [demand 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 (it is precisely it that is prescribed in the passport). If there is no minimum power indicator, then the existing one is underestimated by 15-25% to simplify the calculations.

Area calculation

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 heat energy, the need for one square meter. m. take equal to 100 watts. No adjustments to it are required as long as it is required.

Formulas for calculating the number of sections by area of ​​the room, 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] * [need 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 indicator of modern models is 170 W
4. To determine the required number of sections, use the formula: [total heat demand] / [capacity of one section] (2000/170=11.7)
5. We introduce correction factors ( considered further)
6. It is recommended to round up - we get 12 sections

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

If the whole 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 obtained 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, decrease it.

Premises with an area of ​​more than 25 sq. m. to heat 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. Heat in this case will spread more evenly throughout the room.

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

Having bought stamped radiators, which cannot be divided into sections, it is necessary to take into account the total power of the product. If it is not enough, you should think about buying a second battery of the same or slightly less 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 conventional glazing - magnification factor 1.27
• Insufficient thermal insulation of the walls - increasing factor 1.27
• More than two window openings per room - increasing factor 1.75
• Headers with bottom wiring - multiplying factor 1.2
• Reserve in case of unforeseen situations - increasing coefficient 1.2
• The use of improved thermal insulation materials - reduction factor 0.85
• Installation of high-quality insulating glass units - reduction factor 0.85

The number of corrections made to the calculation can be enormous and depends on each specific situation. However, it should be remembered that it is much easier to reduce the heat transfer of a heating radiator than to increase it. Therefore, all rounding is done upwards.

Summing 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 contact a specialist. The most accurate methods, which are described in special literature, take into account not only the volume or area of ​​the room, but also the temperature outside and inside, the thermal conductivity of various materials from which the box of the house is built, and many other factors.

Of course, you can not be afraid and sketch out a few edges to the result. But an excessive increase in all indicators can lead to unjustified expenses, which are not immediately, sometimes not always possible to recoup.

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 the creation of such a system is the most important task when organizing the construction of your own house or when carrying out major repairs in an apartment of a high-rise building.

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

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

Briefly about the existing types of heating radiators

• Steel radiators of panel or tubular construction.
• 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 small weight and ease of installation.

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

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

Cast iron radiators

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

Perhaps such MC-140-500 batteries did not differ in particular elegance, but they faithfully served more than one generation of residents. Each section of such a radiator provided a heat transfer of 160 watts. The radiator is prefabricated, and the number of sections, in principle, was not limited by anything.

Currently, there are many modern cast iron radiators on sale. They are already distinguished by a more elegant appearance, flat, 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 joints, are not afraid of water hammer, temperature changes.
• Thick cast iron walls are not susceptible to corrosion and abrasion. Almost any heat carrier can be used, so such batteries are equally good for both autonomous and central heating systems.

If you do not take into account the external data of old cast-iron batteries, then one of the shortcomings can be noted the fragility of the metal (accented blows are unacceptable), the relative complexity of installation, associated more with massiveness. In addition, not all wall partitions will be able to support the weight of such radiators.

Aluminum radiators

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

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

Aluminum radiators are on sale both as stackable 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 gassing. This imposes special requirements on the quality of the coolant, therefore, such batteries are usually installed in autonomous heating systems.
• Some non-separable aluminum radiators, sections of which are manufactured using extrusion technology, can leak at the joints under certain unfavorable conditions. At the same time, it is simply impossible to carry out repairs, and you will have to change the entire battery as a whole.

Of all the aluminum batteries, the highest quality is made with the use of anodic oxidation of the metal. These products are practically not afraid of oxygen corrosion.

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

Bimetallic heating radiators

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

Each of the sections consists of two, upper and lower, horizontal steel 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 (pos. 3). High heat dissipation is provided by the outer aluminum shell.

Steel inner pipes are made of metal that does not corrode or has a protective polymer coating. Well, the aluminum heat exchanger does not come into contact with the coolant under any circumstances, and corrosion is absolutely not terrible for it.

Thus, a combination of high strength and wear resistance with excellent thermal performance is obtained.

Prices for popular heating radiators

Heating radiators

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

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

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

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

	Chg	TS	Al	AA	BM
Maximum pressure (atmospheres)
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
PH limitation (hydrogen index)	6,5-9	6,5-9	7-8	6,5-9	6,5-9
Corrosion susceptibility by:
oxygen	No	Yes	No	No	Yes
stray currents	No	Yes	Yes	No	Yes
electrolytic vapors	No	weak	Yes	No	weak
Section capacity 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 may be interested in information about what constitutes

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

The easiest ways to calculate

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

Q = S× 100

Q- the required heat transfer from heating radiators.

S- the area of ​​the heated room.

If you plan to install a non-separable radiator, then this value will become a guideline for the selection of the required model. In the case when batteries will be installed that allow a change in the number of sections, one more calculation should be carried out:

N = Q/ Qus

N- the calculated number of sections.

Qus- specific thermal power of one section. This value is necessarily indicated in the technical passport of the product.

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

Section table

However, it must be remembered that these values ​​are for a 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 thermal power per 1 m³ of volume in a panel house, or 34 W - in a brick one.

Q = S × h× 40 (34)

where h- ceiling height above floor level.

Further calculation is no different from the one presented above.

Detailed calculation taking into account the features premises

Now let's move on to more serious calculations. The simplified calculation technique given above can give the owners of a house or apartment a "surprise". When the installed radiators will not create the required comfortable microclimate in the living quarters. 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 is again taken as a basis and all the same 100 W per m². But the formula itself already looks somewhat different:

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

Letters from A before J the coefficients are conventionally designated, taking into account the features of the room and the installation of radiators in it. Let's consider them in order:

A is the number of external walls in the room.

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

• One outer wall - A = 1.0
• Two outer walls - A = 1.2
• Three outer walls - A = 1.3
• All four walls are external - 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, of course, is the northern side of the house, and the eastern side can also be attributed here - the rays of the Sun are here only in the morning, when the luminary has not yet "reached its full capacity."

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

Hence, the values ​​of the coefficient V :

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

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

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

• The middle level - the walls are lined 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 equal all the basic indicators of the required heating power "one size fits all" - they also depend on the level of winter temperatures below zero, typical for a particular area. This takes into account the coefficient D. To select it, the average temperatures of the coldest decade 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 - 15 ° WITH – D = 0.9
• not lower - 10 ° WITH – D = 0.7

E is the coefficient of the height of the ceilings of the room.

As already mentioned, 100 W / m² is the average value for a standard ceiling height. If it differs, you should enter a correction factor 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 premises located above

Arranging a heating system in rooms with a cold floor is a pointless exercise, and the 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 the top is a residential or insulated room, then the total demand 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 - coefficient of account of the type of installed windows.

Different window structures are not equally susceptible to heat loss. This takes into account the coefficient G:

• ordinary wooden frames with double glazing - G = 1.27
• windows are equipped with a single-chamber double-glazed window (2 glasses) - G = 1.0
• single-chamber glass unit with argon filling or double glass unit (3 glasses) - G = 0.85

H - coefficient of the area of ​​the glazing of the room.

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

• 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 - coefficient taking 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 the bottom - 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 - coefficient taking into account the degree of openness of the installed radiators.

Much also depends on how open the installed batteries are for 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 with a horizontal protrusion of the wall niche - J = 1.07

d - the radiator is covered from above with a window sill, and from the front parties — parts ofwell covered with a decorative cover - 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 that, it remains either to pick up a non-separable radiator with the desired heat output, or to 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 excessively cumbersome, in which it is easy to get confused. To facilitate the calculations, we suggest using a special calculator - all the required values ​​are already included in it. The user only needs to enter the requested initial values ​​or select the necessary items from the lists. The "calculate" button will immediately lead to an accurate result with rounding up.

In the matter of maintaining the optimal temperature in the house, the main place is occupied by the radiator.

The choice is simply amazing: bimetallic, aluminum, steel of various sizes.

There is nothing worse than an incorrectly calculated required heat output in a room. In winter, such a mistake can be very expensive.

Thermal calculation of heating radiators is suitable for bimetallic, aluminum, steel and cast iron radiators. Experts identify three ways, each of which is based on certain indicators.

There are three methods here, which are based on general principles:

• the standard value of the power of one section can vary from 120 to 220 W, therefore the average value is taken
• to correct errors in calculations when buying a radiator, you should lay a 20% reserve

Now let's turn directly to the methods themselves.

Method one - standard

Based on building rules, for high-quality heating of one square meter, 100 watts of radiator power is required. Let's do the calculations.

Suppose the area of ​​the room is 30 m², the power of one section is taken equal to 180 watts, then 30 * 100/180 = 16.6. Let's round the value up and get that 17 sections of a heating radiator are needed for a room of 30 square meters.

However, if the room is angular, then the resulting value should be multiplied by a factor of 1.2. In this case, the number of required radiator sections will be 20

Method two - approximate

This method differs from the previous one in that it is based not only on the area of ​​the room, but also on its height. Please note that this method only works for medium to high power appliances.

At low power (50 watts or less), such calculations will be ineffective due to too large an error.

So, if we take into account that the average height of the room is 2.5 meters (the standard height of the ceilings of most apartments), then one section of a standard radiator is capable of heating an area of ​​1.8 m².

The calculation of sections for a room of 30 "squares" will be as follows: 30 / 1.8 = 16. Rounding up again, we find that 17 radiator sections are needed to heat this room.

Method three - volumetric

As the name implies, the calculations in this method are based on the volume of the room.

It is conventionally assumed that to heat 5 cubic meters of a room, 1 section with a capacity of 200 watts is needed. With a length of 6 m, a width of 5 and a height of 2.5 m, the formula for the calculation will be as follows: (6 * 5 * 2.5) / 5 = 15. Therefore, for a room with such parameters, you need 15 sections of a heating radiator with a capacity of 200 watts each.

If the radiator is planned to be located in a deep open niche, then the number of sections must be increased by 5%.

If the radiator is planned to be completely covered with a panel, then the increase should be made by 15%. Otherwise, it will be impossible to achieve optimal heat dissipation.

An alternative method for calculating the power of heating radiators

Calculating the number of heating radiator sections is far from the only way to properly organize the heating of a room.

Let's calculate the volume of the proposed room with an area of ​​30 sq. m and a height of 2.5 m:

30 x 2.5 = 75 cubic meters.

Now you need to decide on the climate.

For the territory of the European part of Russia, as well as Belarus and Ukraine, the standard is 41 watts of thermal power per cubic meter of room.

To determine the required power, we multiply the volume of the room by the standard:

75 x 41 = 3075 W

Let's round the resulting value up - 3100 watts. For those people who live in very cold winters, this figure can be increased by 20%:

3100 x 1.2 = 3720 W.

Arriving at the store and specifying the power of the heating radiator, you can calculate how many radiator sections are required to maintain a comfortable temperature even in the most severe winter.

Calculation of the number of radiators

The calculation method is an excerpt from the previous paragraphs of the article.

After you calculate the required power for heating the room and the number of radiator sections, you come to the store.

If the number of sections is impressive (this happens in rooms with a large area), then it will be reasonable to purchase not one, but several radiators.

This scheme is also applicable to those conditions when the power of one radiator is lower than required.

But there is another quick way to calculate the number of radiators. If in your room there were old ones with a height of about 60 cm, and in winter you felt comfortable in this room, then count the number of sections.

Multiply the resulting figure by 150 W - this will be the required power of the new radiators.

If you choose or, you can buy them at the rate of 1 to 1 - for one rib of a cast-iron radiator, 1 rib of a bimetallic one.

The division into a "warm" and "cold" apartment has long come into our lives.

Many people deliberately do not want to engage in the selection and installation of new radiators, explaining that “it will always be cold in this apartment”. But this is not the case.

The correct choice of radiators, coupled with a competent calculation of the required power, can make your windows warm and cozy even in the coldest winter.

When designing a new home or replacing an old heating system, you need to know the required number of batteries for each room. Measurements "by eye" are ineffective. An accurate calculation of the number of heating radiators per area is necessary, otherwise it will be either very cold in the room if there are not enough heat sources, or, conversely, too hot with their excess, which will lead to an undesirable regular overspending of resources.

To calculate the number of radiators per area, different methods are used, the essence of which boils down to one thing - to determine the heat loss of a room at different outdoor temperatures and calculate the required number of batteries to compensate for heat loss.

Classical technique

Today there are a lot of calculation methods. Elementary schemes - in terms of area, ceiling height and region, give only approximate results. More accurate, where all the characteristics of the room are taken into account (location, the presence of a balcony, the quality of doors and windows, etc.) and special coefficients are used, give a truly optimal result when the room will always be at a comfortable temperature for a person.

In most cases, builders or homeowners use the popular method of calculating a heating radiator by area before renovation. It is relevant for rooms with a ceiling height of about 2.5 meters. This minimum sanitary standard has been in effect since Soviet times, so the bulk of apartment buildings were guided by this value.

It is worth considering that before calculating aluminum heating radiators for an area or cast iron, this method does not take into account many correction factors regarding the individual characteristics of the room (wall thickness, glazing, etc.).

The calculation of the heating battery by area is carried out based on a constant that determines that 100 W of thermal energy is required to heat 1 m 2 in a room.

Example for a room of 20 square meters:

20 m 2 x 100 W = 2000 W

The estimated thermal power required for such a room is about 2000 W.

Each battery consists of several separate sections, assembled during installation into a single module. The selection of a radiator by the area of ​​the room is carried out based on its output characteristics specified by the manufacturer. Such data are indicated in the passport that comes with the radiator. Before calculating the number of heating radiator sections, it is advisable to find out these numbers. All this information is in the technical data sheet, it can also be obtained from a consultant when purchasing or on the Internet on the manufacturer's website.

For example, when the instruction gives a value for one section of 180 W, then in order to find out the total number of sections, you will need to divide the total required power by the output value of a separate section:

2000W: 180W = 11.11 pieces

The value that this calculation of heating radiators will give must be correctly rounded. This should always be done in the big direction in order to fully provide the interior with warmth. That is, in the above example, 12 batteries will be installed.

This technique is relevant for apartment buildings where the coolant temperature is about 70C. You can also use another simplified method. According to the following calculation of radiators per area, the constant is a value of 1.8 m 2. It should be heated by one conventional medium-sized section.

For a room of 22 square meters, the calculation will turn out:

However, this approximate calculation of heating radiators is not allowed when installing modules with increased heat transfer at the level of 150-200 W from each section.

It is necessary to heat the entire volume of air, therefore it is more rational to determine the required number of radiators by volume.

Application of correction factors

During a preliminary, more rigorous calculation of batteries by area, it will be necessary to make an adjustment for individual characteristics associated with the building, the heating system, the sections themselves, etc.

In most cases, it is possible to reduce the error by knowing the following information:

• water used as a heat carrier has a lower thermal conductivity than heated steam;
• for a corner room, it is necessary to raise the number of radiators by 15-20%, depending on its degree and quality of insulation;
• for rooms with ceilings above 3 meters, the heating radiator is calculated not by area, but by the volume of the room;
• a larger number of windows will give less warm initial conditions; it is advisable to divide the sections in the room for installation under each window;
• different materials of radiators have different degrees of thermal conductivity;
• for a colder climatic zone, it is necessary to make an increased correction factor;
• old wooden frames have worse thermal conductivity than newer double-glazed windows;
• when the coolant moves from top to bottom, a noticeable increase in power up to 20%

Approximate heat loss

• the ventilation used assumes increased power.

Why batteries are always placed under a window

Any radiator, regardless of type, design and material, is based on warm air convection. As the air heats up, it rises up, in its place the cold air "comes", which also heats up, and again a new portion of cold air rises. Such constant circulation ensures uniform heating of the entire area of ​​the room, provided that the amount of heat sources is correctly calculated.

A window in any room is a cold bridge, which, due to its design and a large heat-dissipating surface, allows more cold air to pass through than walls and even the front door. The heat source installed under the window has time to warm up the cold air coming from the window and it enters the room already warm. If the heating elements are not placed under the window, but in any other place in the room, the cold stream coming from the window will circulate through the room. And even the most powerful radiator is not enough to neutralize the cold imperceptibly.

VIDEO: What errors can be encountered when calculating

Calculation based on the volume of the room

The proposed calculation of a heating radiator by volume is in essence similar to the calculation of radiator sections by the area of ​​a room. However, here the basic value is not the area, but the volume of the room. First, you need to get the value of the volume of the room. Domestic standards SNIP assume 41 W of heat for heating 1 m 3 of the room. To find the volume, you need to multiply the height, length and width of the room.

For example, let's take a room area of ​​22 square meters with ceilings of 3 meters in height. We get the required volume:

With the obtained value, we calculate the heating radiators. The total power must be divided by the issued nameplate value by one section:

2706 W: 180 W = 15 pieces

Each manufacturer enters into the instructions for use often slightly overestimated values, assuming that heating in most cases operates with the maximum temperature of the coolant.

If an interval of power values ​​is indicated in the passport, then the smaller of them is taken into account of the number of heating radiators in order to obtain more accurate output values.

Detailed calculations

Conscientious builders or homeowners can use a large number of correction factors in the formula for calculating the number of heating radiators. With their help, it will be possible to approach the calculation process individually in each case, which will provide comfort in the room without wasting extra calories of heat.

The formula looks like this:

P = 100 (W) x S (m 2) x p1 x p2 x p3 x p4 x p5 x p6 x p7

• p1 - ​​correction for the presence of double-glazed windows (triple - 0.85, doubled 1, without it 1.27);
• p2 - degree of thermal insulation (new - 0.85, standard in 3 bricks - 1.0, weak - 1.27);
• p3 is the ratio of window areas to the floor (0.1 - 0.8, 0.2 - 0.9, 0.3 - 1.1, 0.4 - 1.2);
• p4 - value of peak negative temperatures (from - 11 0 С - 0.7, from - 16 0 С - 0.9, from -21 0 С - 1.1, from - 25 0 С - 1.3)
• p5 is an amendment that takes into account the number of external walls in the room (1 - 1.1, 2 - 1.2, 3 - 1.3, 4 - 1.4);
• p6 - a kind of interior located above the shelf (heated room - 0.8, warm attic room - 0.9, cold attic room - 1.0);
• p7 is the vertical value from floor to ceiling (2.50 - 1, 3.0 - 1.05, 3.5 - 1.1, 4.5 - 1.2).

It is not difficult to roughly calculate how many heat sources will be needed in a room. But to determine this exactly, having installed all the cold bridges and correctly taking into account the coefficients - this is already a task with many unknowns. We told you how to do it correctly, now there is little left to do - instead of approximate indicators, enter your own and calculate.

VIDEO: Calculation of the number of heating radiators per area for individual types