Calculation of sections of cast-iron heating radiators by area. How to correctly calculate the number of sections of heating radiators: formula and examples
For each owner of the house, it is very important to carry out the correct calculation of heating radiators. An insufficient number of sections will contribute to the fact that the radiators will not be able to heat the room in the most efficient and optimal way. If you purchase radiators that have too many sections, then the heating system will be very uneconomical, using the excess power of heating radiators.
If you need to change the heating system or install a new one, then the calculation of the number of sections of heating radiators will play a very important role. If the premises in your house or apartment are of a standard type, then simpler calculations will do. However, sometimes, in order to obtain the highest result, it is necessary to observe some features and nuances regarding such parameters as the power of the heating radiator per room and the pressure in the heating batteries.
Calculation based on the area of \u200b\u200bthe room
Let's figure out how to calculate heating batteries. Focusing on parameters such as the total area of the room, it is possible to carry out a preliminary calculation of heating batteries per area. This calculation is quite simple. However, if you have high ceilings in the room, then it cannot be taken as a basis. For each square meter of area, about 100 watts of power per hour will be required. Thus, the calculation of sections of heating batteries will allow you to calculate how much heat is needed to heat the entire room.
How to calculate the number of heating radiators? For example, the area of our premises is 25 square meters. meters. We multiply the total area of the room by 100 watts and get the power of the heating battery at 2500 watts. That is, 2.5 kW per hour is needed to heat a room with an area of 25 square meters. meters. The result obtained is divided by the value of heat that one section of the heating radiator is able to allocate. For example, the documentation of a heater indicates that one section emits 180 watts of heat per hour.
Thus, the calculation of the power of heating radiators will look like this: 2500 W / 180 W = 13.88. We round the result and get the number 14. So, for heating a room of 25 square meters. meters will require a radiator with 14 sections.
You will also need to take into account various heat losses. A room that is located in the corner of the house, or a room with a balcony, will heat up more slowly and also give off heat faster. In this case, the calculation of heat transfer from the radiator of heating batteries should be carried out with some margin. It is desirable that such a margin is about 20%.
The calculation of heating batteries can also be made taking into account the volume of the room. In this case, not only the total area of the room plays a role, but also the height of the ceilings. How to calculate heating radiators? The calculation is made approximately according to the same principle as in the previous situation. First you need to determine how much heat is needed, as well as how to calculate the number of heating batteries and their sections.
For example, you need to calculate the amount of heat needed for a room that has an area of 20 square meters. meters, and the height of the ceilings in it is 3 meters. We multiply 20 sq. meters by 3 meters in height and get 60 cubic meters of the total volume of the room. For each cubic meter, about 41 W of heat is needed - this is what the data and recommendations of SNIP say.
We calculate the power of heating batteries further. We multiply 60 sq. meters at 41 watts and get 2460 watts. We also divide this figure by the heat output that one section of the heating radiator radiates. For example, the documentation of a heater indicates that one section emits about 170 W of heat per hour.
We divide 2460 W by 170 W and get the figure 14.47. We also round it up, so to heat a room with a volume of 60 cubic meters, you need a 15-section heating radiator.
You can make the most accurate calculation of the number of heating radiators. This may be necessary for private houses with non-standard premises and rooms.
CT = 100W/sq.m. x P x K1 x K2 x K3 x K4 x K5 x K6 x K7
Kt is the amount of heat that is needed for a particular room;
P - the total area of the room;
K1 is a coefficient that takes into account how glazed window openings are.
If the window with simple double glazing is of the double type, then kf. is 1.27.
For a window with a double-glazed window - 1.00.
For triple glazing kf. is 0.87.
K2 is kf. wall insulation.
If the thermal insulation is rather low, then cf is taken. at 1.27.
For good thermal insulation - kf. = 1.0.
For excellent thermal insulation kf. equals 0.85.
K3 is the ratio of floor area to window area in the room.
For 50% it will be equal to 1.2.
For 40% - 1.1.
For 30% - 1.0.
For 20% - 0.9.
For 10% - 0.8.
K4 is a factor that takes into account the average room temperature during the coldest week of the year.
For a temperature of -35 degrees, it will be equal to 1.5.
For -25 - cf. = 1.3.
For -20 - 1.1.
For -15 - 0.9.
For -10 - 0.7.
K5 is a coefficient that will help determine the need for heat, taking into account how many external walls the room has.
For a room with one wall kf. is 1.1.
Two walls - 1.2.
Three walls 1.3.
K6 - takes into account the type of premises that are located above our premises.
If the attic is not heated, then it is 1.0.
If the attic is heated, then kf. equals 0.9.
If a dwelling is located above, which is heated, then kf is taken as the basis. at 0.7.
K7 is the accounting for the height of the ceilings in the room.
For a ceiling height of 2.5m, kf. will be equal to 1.0.
With a ceiling height of 3 meters kf. equals 1.05.
If the ceiling height is 3.5 meters, then the cf is taken as the basis. in 1.1.
At 4 meters - 1.15.
The result calculated according to this formula must be divided by the heat that one section of the heating radiator produces, and round the result that we received.
At first glance, it is easy to calculate how many radiator sections to install in a particular room. The larger the room, the more sections the radiator should consist of. But in practice, how warm it will be in a particular room depends on more than a dozen factors. Given them, it is possible to calculate the required amount of heat from radiators much more accurately.
General information
The heat transfer of one section of the radiator is indicated in the technical characteristics of products from any manufacturer. The number of radiators in a room usually corresponds to the number of windows. Radiators are most often located under the windows. Their dimensions depend on the area of the free wall between the window and the floor. It should be borne in mind that the radiator must be lowered from the window sill by at least 10 cm. And between the floor and the bottom line of the radiator, the distance must be at least 6 cm. These parameters determine the height of the device.
The heat output of one section of a cast-iron radiator is 140 watts, more modern metal ones - from 170 and above.
You can calculate the number of sections of heating radiators , leaving the area of \u200b\u200bthe room or its volume.
According to the norms, it is considered that 100 watts of thermal energy is needed to heat one square meter of a room. If we proceed from the volume, then the amount of heat per 1 cubic meter will be at least 41 watts.
But none of these methods will be accurate if you do not take into account the characteristics of a particular room, the number and size of windows, the material of the walls, and much more. Therefore, when calculating the radiator sections according to the standard formula, we will add the coefficients created by one or another condition.
Room area - calculation of the number of sections of heating radiators
Such a calculation is usually applied to premises located in standard panel residential buildings with a ceiling height of up to 2.6 meters.
The area of the room is multiplied by 100 (the amount of heat for 1m2) and divided by the heat output of one section of the radiator indicated by the manufacturer. For example: the area of the room is 22 m2, the heat transfer of one section of the radiator is 170 watts.
22X100/170=12.9
This room needs 13 radiator sections.
If one section of the radiator has 190 watts of heat transfer, then we get 22X100 / 180 \u003d 11.57, that is, we can limit ourselves to 12 sections.
You need to add 20% to the calculations if the room has a balcony or is located at the end of the house. A battery installed in a niche will reduce heat transfer by another 15%. But in the kitchen it will be 10-15% warmer.
We make calculations according to the volume of the room
For a panel house with a standard ceiling height, as already mentioned above, the heat calculation is based on the need for 41 watts per 1m3. But if the house is new, brick, double-glazed windows are installed in it, and the outer walls are insulated, then 34 watts per 1 m3 are already needed.
The formula for calculating the number of radiator sections looks like this: the volume (area multiplied by the height of the ceiling) is multiplied by 41 or 34 (depending on the type of house) and divided by the heat transfer of one section of the radiator indicated in the manufacturer's passport.
For example:
The area of the room is 18 m2, the ceiling height is 2.6 m. The house is a typical panel building. The heat output of one section of the radiator is 170 watts.
18X2.6X41 / 170 \u003d 11.2. So, we need 11 radiator sections. This is provided that the room is not corner and it does not have a balcony, otherwise it is better to install 12 sections.
Calculate as accurately as possible
And here is the formula by which you can calculate the number of radiator sections as accurately as possible :
The area of the room multiplied by 100 watts and by the coefficients q1, q2, q3, q4, q5, q6, q7 and divided by the heat transfer of one section of the radiator.
More about these ratios:
q1 - type of glazing : with triple glazing, the coefficient will be 0.85, with double glazing - 1 and with conventional glazing - 1.27.
Heating a dwelling in our climate is the most urgent task for owners of country houses.
On the one hand, it is necessary to ensure a comfortable thermal regime, on the other hand, an optimal energy consumption.
In order to correctly solve this problem, and determine how many sections of heating radiators (bimetallic, steel, cast iron, etc.) are needed, it is necessary to make a reliable calculation based on the area of \u200b\u200bthe room using the online calculator located below.
Indicate in the calculator the scheme for connecting radiators
Mandatory reading explanation of online calculator calculations
Types of heating devices - main characteristics
Before purchasing the elements of the heating system, it is necessary not only to calculate them, but to calculate the entire system so that its individual components are mutually consistent in all respects. These elements include:
- heating network boilers;
- radiators;
- pipelines;
- a circular pump, if one is provided for by the project;
- expansion tank - currently, as a rule, membrane units are used.
What you need to know when choosing radiators
When purchasing batteries for a heating system, you need to consider the following parameters:
- Calculate the number of sections of heating radiators, based on the number of heated rooms in the house.
- Maximum allowable working pressure.
- Power.
- Design features that may affect the installation of the heating network and the necessary components for this.
Currently, the construction market offers the following main types of heat exchangers for heating systems.
Cast iron
The positive aspects of these products include a presentable appearance and ease of care for them.
Bimetallic
Such heat transfer devices combine the best properties of steel and aluminum products. Their inner part at the points of contact with the coolant is made of stainless steel. This predetermines the long life of the device, since the base material is resistant to aggressive agents and does not tend to adsorb rust elements. The outer part shows its best qualities, corresponding to the material of manufacture. It has a presentable appearance, easy to maintain and clean.
Since the stainless steel interior is made of thin-walled metal, its low thermal conductivity does not adversely affect the operation of the device.
Copper heat exchangers
Suffice it to say that with the same characteristics, a copper radiator weighs several times less, and the heat transfer from it is many times higher.
This contributes to a significant reduction in energy costs for heating residential and industrial buildings.
Copper has sufficiently high mechanical strength, which allows the use of pipes from it at temperatures up to 150 degrees at a pressure of 16 atmospheres.
In addition, copper heating systems have a presentable appearance.
Method for calculating heating radiators by area
Comfortable living in any living space is ensured by an optimally tuned heating system. Its formation is impossible without knowledge of modern methods of formation of heating systems, which includes the possession of methods for calculating heating radiators.
It should be noted that heat engineering calculations in construction are the most complex. It is safe to say that a detailed and reliable calculation can only be performed by highly qualified specialists or specialized organizations.
The basis for calculating radiators is based on accounting for heat losses in the room, which must be replenished in the process of life by the heat transfer of the heating system. Nevertheless, allowing redistributed simplifications, one can obtain a result close to reliable independently.
Heating power selection
When choosing a heating scheme for a small private house, this indicator is decisive.
To calculate the sections of bimetallic heating radiators by area, you need to determine the following parameters:
- the amount of necessary compensation for heat losses;
- the total area of the heated room.
In construction practice, it is customary to use the first indicator in the above form as 1 kW of power per 10 square meters, i.e. 100 W/m2. Thus, the ratio for the calculation will be the following expression:
N = S x 100 x 1.45,
where S is the total area of the heated premises, 1.45 is the coefficient of possible heat losses.
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 \u003d 20 (m 2);
- 20 x 100 = 2000 (W);
- 2000 x 1.4 = 2900 (W).
A typical place for installing a radiator is the space under the window, so we use two radiators of the same power of 1450 watts. This indicator can be influenced by adding or reducing the number of sections installed in the battery. It should be borne in mind that the power of one of them is:
- for bimetallic 50 centimeters high - 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.
By using glass packages, heat loss on windows can be reduced by about 25%.
Calculation of sections of bimetallic heating radiators by area gives a clear primary idea of their required number.
Accounting for the features of the room
Technical characteristics of different types of radiators are not the same. Heating engineers recommend using cast iron radiators in private homes; bimetallic or aluminum products are more suitable for an apartment.
The calculation of the size of the sections takes into account not only the quadrature, but also the probable heat losses occurring through windows, doors, walls, ceilings and floors, as well as through ventilation ducts. For each type of unproductive heat consumption, its own coefficients are used, denoted by the letter Q.
The following parameters must be included in the calculation of heat losses:
- Temperature difference between outside and inside, referred to as DT.
- The area of doors and windows and other similar structures - S.
- The thickness of partitions or walls - V.
- The value of the thermal conductivity of the walls, depending on the nature of the material and the insulation materials used - Y.
The calculation ratio looks like this:
Q = S x DT / R layer,
where R=V:Y.
All calculated coefficients must be summed up, and in the presence of ventilation shafts, the resulting figure increases by up to 40%.
The result is divided by the area of \u200b\u200bthe house and added to the indicator of the estimated power of the heating batteries.
Depending on the location of the rooms in space, additional coefficients are introduced for verticals facing north, northeast and northwest. It is 10%, and for those facing the southeast and southwest - 5%. For the southern direction, the amendment does not apply. For a corner room with two walls facing the outside, the additional coefficient is taken equal to 5%.
If the wall height is more than 4 meters, an additional factor of 2% is introduced. A reduction in heat loss parameters can be obtained by insulating the ceiling from the attic side and the roofing pie.
Influence of other devices of the heating system
The calculation of heating radiators is the first link in the chain of such actions in relation to the entire heating system as a whole. In particular, its result directly affects the selection of the power of the heating boiler.
In addition, the balance of heating in the room is affected by the heat dissipation of piping.
Taking into account the many factors that affect the operation of the heating system, special calculators have been developed that allow you to quickly and with sufficient accuracy calculate the number of heating radiators based on the area of \u200b\u200bthe heated room. Many such programs have been developed, and they all work according to different algorithms. But their results can be trusted.
Calculation of heating radiators per square meter with a calculator developed for our website will significantly reduce the time for performing auxiliary operations with sufficient accuracy of the heat output result.
The efficiency of a heating system depends on many factors. But, as is clear from the above information, heating costs can be optimized by paying attention to the following factors:
- It has been established that the main losses of thermal energy occur in the upper part of the house and range from 25-30% with an uninsulated roof.
- Losses are also significant with insufficiently insulated floors.
- The material from which the walls are made matters. Being installed from concrete blocks or cast walls, the enclosing structures quickly lose heat to the external space, which requires additional costs for their heating and maintenance in this state for a long time.
- Floor insulation is of particular importance. Being constantly cold, it creates uncomfortable living conditions and creates a lot of inconvenience. In addition, underfloor heating significantly reduces the temperature of the main heating circuit, which saves fuel resources. But it should be remembered that the surface temperature of the warm floor should not exceed 30 degrees. Otherwise, ascending convection currents arise, raising dust from the floor, which is harmful to humans.
Thus, after reading this article, you will be able to independently calculate the required number of sections for radiators using formulas and check the correctness of the information received using a calculator.
During the cold season, heating is the most important communication system that is responsible for comfortable living in the house. Heating batteries are part of this system. The general temperature regime of the room will depend on their number and area. Therefore, a correctly calculated number of radiator sections is the key to the efficient operation of the entire system, plus fuel savings 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;
- the number of windows and entrance doors, their area;
- materials from which the house was built (in this case, walls, floor and ceiling are taken into account);
- the location of the room relative to the cardinal points;
- technical parameters of the heating device.
If you are not a specialist, it will be very difficult to independently carry out calculations 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 the calculated calculations according to SNiP.
Calculation method according to SNiP
Table of approximate calculations
The SNiP stipulates that the optimal variant of the required number of radiator sections depends on the indicator of the thermal energy that they emit. It should be equal to 100 W per 1 m² of room area.
The formula is used for calculation: N=Sx100/P
- N is the number of battery sections;
- S is the area of the room;
- P - section power (this indicator can be found in the product passport).
But since additional indicators must be taken into account in the calculation, new variables are added to the formula.
Corrections 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 the calculation.
- If ceiling height is 2.5 meters, a factor 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 the outer walls also affect 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 a heated attic or attic is organized 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 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: an 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 - it turns out 16 sections: two batteries for each window, 8 sections each.
Explanation on coefficients:
- 1.05 is a 5% markup for the second window;
- 1.1 is an increase in the height of the ceiling;
- 0.9 is a reduction for the installation of plastic windows.
Let's face it - this option, as noted above, is difficult for a simple consumer. But there are simplified ways, which will be discussed below.
Effect of material on the number of sections
Developers often face the question, in the context of the material from which they are made. After all, steel, cast iron, copper, aluminum has its own heat transfer index, and this must also be taken into account in the calculations.
As mentioned above, this parameter can be found in the product passport.
For example:
- Cast iron radiator has a heat output of 145 watts.
- Aluminum - 190 W.
- Bimetallic - 185 watts.
From this list, we can conclude that the number of aluminum sections will be used less than, say, cast iron. And more than bimetallic. And this is with all the other parameters mentioned above being the same.
Calculation by room area
The same formula is used here - N \u003d Sx100 / P, with one caveat: ceiling height should not exceed 2.6 m.
We 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.
- For simplicity of the example, let's take just one window: 22x100/145=15.17
You can round down - up 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 thermal energy is the main indicator, 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 watts is used.
- 22x2.6x41 / 145 \u003d 16.17 - rounded up, it turns out 16 sections.
Pay attention to one very subtle nuance.
Manufacturers, indicating the amount of heat transfer in the product passport, take it into account according to the maximum parameter. In other words, they believe that the temperature of the hot water in the system will be maximum. In real life this is not always true. Therefore, we strongly recommend that you round the final result up.
And if the power of the section is determined by the manufacturer in a certain range (a plug is set 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 absolutely do not understand anything in mathematical calculations. Divide the area of \u200b\u200bthe room by the standard indicator - 1 section per 1.8 m².
- 22 / 1.8 \u003d 12.22 - rounded up, it turns out 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, you can calculate the required number of sections for a room in different ways. If you want to get an accurate result, use the calculation according to SNiP. You will not be able to decide on additional coefficients - choose any other simplified option.
Dear users of our resource! On our site you have the opportunity to choose a radiator yourself. This means that you can calculate the number of radiators you need to install in each room. In order to make this calculation, to have certain calculation information at hand, only then can radiators be selected with greater accuracy. Information needed to determine the number of radiator sections: The main one is the heat output of the radiator (heat transfer) - this is a value that shows how much heat energy the radiator gives off in a certain unit of time. Thermal power is expressed in watts. For each radiator, this value is determined by the manufacturer. Let's move on to the calculation part. From the foregoing, we come to the conclusion that it is necessary to determine the thermal power required to heat a particular room, for this we just need the dimensions of the room. The next step. Be patient, find a pencil, paper, tape measure and prepare the following information for the correct selection of radiators: window type, thermal insulation quality, window and floor area, average temperature of the coldest week of the year, type of room above the calculated one, room size. So, if you have collected all the necessary information, let's get started.
Selection of a heating radiator (calculation of the number of sections)
Now you need to decide which radiators you want to install: aluminum radiators (extruded and die-cast); steel radiators (tubular, panel); bimetallic radiators (extrusion and injection molded); cast iron radiators (tubular). So, if you have already opted for radiators of a certain type, then the next question that arises is how to choose a radiator from the already existing variety that meets specific requirements. You can find out how to choose a heating radiator in the section "Articles" - "Articles about heating radiators"
