It's time to change the batteries.
The comfort in the cold season depends on the calculations of the number of knots.
How to correctly make all calculations, measurements?
Everything is quite simple if you follow the instructions below.
Before you purchase heating batteries, consider ways to calculate the number of their elements.
The first method is based on the area of \u200b\u200bthe room. Building codes (SNiP) state that for normal heating, 1 sq. m. requires 100 watts. thermal power. By measuring the length, width of the room, and multiplying these two values, we get the area of \u200b\u200bthe room (S).
To calculate total power (Q), substitute in the formula, Q \u003d S * 100 W., our value. The passport for heating radiators indicates the heat transfer of one element (q1). Thanks to this information, we will find out the required number of them. To do this, we divide Q by q1.
The second way is more accurate. It should also be used with a ceiling height of 3 meters. Its difference lies in the measurement of the volume of the room. The area of \u200b\u200bthe room is already known, let's measure the height of the ceiling, then multiply these values. The resulting volume value (V) is substituted into the formula Q=V*41 W.
According to building codes 1 cu. m. should be heated by 41 watts. thermal power. Now let's find the ratio of Q to q1, getting the total number of radiator nodes.
Let's sum up the intermediate result, take out data that will be needed for all types of calculations.
- wall length;
- wall width;
- Ceiling height;
- Power ratings, heating a unit area or volume of a room. They are given above;
- Minimum heat dissipation radiator element. It must be indicated in the passport;
- Wall thickness;
- Number of window openings.
A quick way to calculate the number of sections
When it comes to replacing cast-iron radiators with bimetallic ones, you can do without scrupulous calculations. Taking into account several factors:
- Bimetal section gives a ten percent increase in thermal power compared to cast iron.
- Battery efficiency degrades over time. This is due to deposits that cover the walls inside the radiator.
- It's better to be warmer.
The number of elements of a bimetallic battery must be the same as that of its predecessor. However, this number increases by 1 - 2 pieces. This is done to combat a future decrease in the efficiency of the heater.
For a standard room
We already know this method of calculation. It is described at the beginning of the article. Let's analyze it in detail, referring to a specific example. We calculate the number of sections for a room of 40 square meters. m.
According to the rules of 1 sq. m requires 100W. Let's assume that the power of one section is 200 watts. Using the formula, from the first section we find the required heat output of the room. Multiply 40 sq. m. per 100 W, we get 4 kW.
To determine the number of sections, divide this number by 200 watts. It turns out that for a room with a given area, 20 sections will be required. The main thing to remember is that the formula is relevant for apartments where the ceiling height is less than 2.7 m.
For non-standard
Non-standard rooms include corner, end rooms, with several window openings. This category also includes dwellings with a ceiling height of more than 2.7 meters.
For the first, the calculation is carried out according to the standard formula, but the final result is multiplied by a special coefficient, 1 - 1.3. Using the data obtained above: 20 sections, let's assume that the room is corner and has 2 windows.
The final result is obtained by multiplying 20 by 1.2. This room requires 24 sections.
If we take the same room, but with a ceiling height of 3 meters, the results will change again. Let's start by calculating the volume, multiply 40 square meters. m. by 3 meters. Remembering that for 1 cu. m requires 41 W., we calculate the total thermal power. Received 120 cu. m multiply by 41 W.
We get the number of radiators by dividing 4920 by 200 watts. But the room is corner with two windows, therefore, 25 must be multiplied by 1.2. The end result is 30 sections.
Accurate calculations with many parameters
It is difficult to make such calculations. The above formulas are valid for a normal room in central Russia. The geographical location of the house and a number of other factors will introduce additional correction factors.
- Final formula, for a corner room, should have an additional multiplier of 1.3.
- If the house is not located in the middle zone of the country, an additional coefficient is described by the building codes of this territory.
- It is necessary to take into account the installation location of the bimetallic radiator and decorative items. For example, a niche under the window will take 7%, and a screen up to 25% of the thermal power of the battery.
- What will the room be used for?
- Wall material and thickness.
- What are the frames and glass.
- Door and window openings introduce additional problems. Let's dwell on them in more detail.
Walls with windows, street and doorways, change the standard formula. It is necessary to multiply the resulting number of sections by the heat transfer coefficient of the room, but it must first be calculated.
This indicator will be the sum of the heat transfer of the window, doorway and wall. All this information can be obtained by contacting the SNiP, according to your type of premises.
Electric oil coolers, working principle and how to choose on
Useful tips for the proper arrangement of the heating system
Bimetallic radiators come from the factory connected in 10 sections. After calculations, we got 10, but we decided to add 2 more in reserve. So, it's better not to. Factory assembly is much more reliable, it is guaranteed from 5 to 20 years.
The 12-section assembly will be done by the store, and the warranty will be less than a year. If the radiator leaks shortly after the end of this period, repairs will have to be carried out on their own. The result is unnecessary problems.
Let's talk about the effective power of the radiator. Characteristics of the bimetallic section specified in the product passport, proceed from the fact that the temperature difference of the system is 60 degrees.
Such pressure is guaranteed if the battery coolant temperature is 90 degrees, which does not always correspond to reality. This must be taken into account when calculating the room radiator system.
Below are some tips for installing the battery:
- Distance from the window sill to the top edge of the battery, must be at least 5 cm. The air masses will be able to circulate normally and transfer heat to the entire room.
- The radiator needs to lag behind the wall by a length of 2 to 5 cm. If reflective thermal insulation will be attached behind the battery, then you need to purchase elongated brackets that provide the specified clearance.
- The bottom edge of the battery is supposed to be indented from the floor equal to 10 cm. Failure to follow the recommendations will impair heat transfer.
- A radiator mounted against a wall, and not in a niche under a window, must have a gap with it, at least 20 cm. This will prevent the accumulation of dust behind it and help to heat the room.
It is very important to make such calculations correctly. It depends on how efficient and economical the resulting heating system will be. All the information given in the article is intended to help the average person with these calculations.
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 a 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.
Everything about steel heating radiators: power calculation (table), determination taking into account heat loss, percentage increase and calculation by area of the room, as well as how to choose panel batteries.
From how correctly and competently the calculation of the power of a steel radiator was made, you can also expect heat from it.
In this case, it is necessary to take into account that the technical parameters of the heating system and the heater coincide.
Calculation by room area
To maximize the heat transfer of steel radiators, you can use the calculation of their capacities, based on the size of the room.
If we take as an example a room with an area of 15 m2 and ceilings 3 m high, then by calculating its volume (15x3 = 45) and multiplying by the number of required W (according to SNiP - 41 W / m3 for panel houses and 34 W / m3 for brick ), it turns out that the power consumption is 1845 W (panel building) or 1530 W (brick).
After that, it is enough to make sure that the calculation of the power of steel heating radiators (you can check the table provided by the manufacturer) corresponds to the parameters obtained. For example, when buying a type 22 heater, you need to give preference to a design that has a height of 500 mm and a length of 900 mm, which is characterized by a power of 1851 watts.
If you have to replace old batteries with new ones or rebuild the entire heating system, then you should carefully read the requirements of SNiP. This will eliminate possible shortcomings and violations during installation work.
Steel heating radiators: power calculation (table)
Determination of power taking into account heat losses
In addition to the indicators associated with the material from which the apartment building is built and indicated in the SNiP, the temperature parameters of the air outside can be used in the calculations. This method is based on accounting for heat loss in the room.
For each climatic zone, a coefficient is determined in accordance with cold temperatures:
- at -10 ° C - 0.7;
- - 15 ° C - 0.9;
- at -20 ° C - 1.1;
- - 25 ° C - 1.3;
- up to - 30 ° C - 1.5.
The heat output of steel heating radiators (table provided by the manufacturer) must be determined taking into account the number of external walls. So if there is only one in the room, then the result obtained when calculating steel heating radiators by area must be multiplied by a factor of 1.1, if there are two or three of them, then it is equal to 1.2 or 1.3.
For example, if the temperature outside the window is 25 ° C, then when calculating a steel radiator of type 22 and the required power of 1845 W (panel house) in a room where there are 2 external walls, you get the following result:
- 1845x1.2x1.3 = 2878.2 W. This indicator corresponds to panel structures of the 22nd type, 500 mm high and 1400 mm long, having a power of 2880 watts.
This is how panel heating radiators are selected (calculation by area, taking into account the heat loss coefficient). A similar approach to choosing the power of a panel battery will ensure its most efficient operation.
To make it easier to calculate steel heating radiators by area, the online calculator will do this in a matter of seconds, just enter the necessary parameters into it.
Percent power increase
It is possible to take into account heat losses not only along the walls, but also windows.
For example, before choosing a steel heating radiator, the area calculation must be increased by a certain percentage, depending on the number of windows in the room:
Taking into account such nuances before installing steel panel batteries allows you to choose the right model correctly. This will save money on its operation with maximum heat transfer.
Therefore, one should not think only about how to choose steel heating radiators according to the area of \u200b\u200bthe room, but also take into account its heat loss and even the location of windows. Such an integrated approach allows you to take into account all the factors that affect the temperature in an apartment or house.
Most likely you have already decided for yourself Which heating radiators are better, but you need to calculate the number of sections. How to perform it accurately and accurately, take into account all the errors and heat losses?
There are several calculation options:
- by volume
- by room area
- and full calculation including all factors.
Let's consider each of them
Calculation of the number of sections of heating radiators by volume
If you have an apartment in a modern house, with double-glazed windows, insulated outer walls and, then the value of the thermal power of 34W per 1 cubic meter of volume is already used for the calculation.
An example of calculating the number of sections:
Room 4*5m, ceiling height 2.65m
We get 4 * 5 * 2.65 \u003d 53 cubic meters The volume of the room and multiply by 41 watts. Total required thermal power for heating: 2173W.
Based on the data obtained, it is not difficult to calculate the number of radiator sections. To do this, you need to know the heat transfer of one section of the radiator you have chosen.
Let's say:
Cast iron MS-140, one section 140W
Global 500,170W
Sira RS, 190W
It should be noted here that the manufacturer or seller often indicates an overestimated heat transfer calculated at an elevated temperature of the coolant in the system. Therefore, focus on the lower value indicated in the product data sheet.
Let's continue the calculation: we divide 2173 W by the heat transfer of one section of 170 W, we get 2173 W / 170 W = 12.78 sections. We round up towards a whole number, and we get 12 or 14 sections.
Some sellers offer a service for assembling radiators with the required number of sections, that is, 13. But this will no longer be a factory assembly.
This method, like the next one, is approximate.
Calculation of the number of sections of heating radiators according to the area of \u200b\u200bthe room
It is relevant for the height of the ceilings of the room 2.45-2.6 meters. It is assumed that 100W is enough to heat 1 square meter of area.
That is, for a room of 18 square meters, 18 square meters * 100W = 1800W of thermal power is required.
We divide by the heat transfer of one section: 1800W / 170W = 10.59, that is, 11 sections.
In which direction is it better to round the results of calculations?
The room is corner or with a balcony, then we add 20% to the calculations
If the battery is installed behind the screen or in a niche, then heat loss can reach 15-20%
But at the same time, for the kitchen, you can safely round down, up to 10 sections.
In addition, in the kitchen, it is very often mounted. And this is at least 120 W of thermal assistance per square meter. 
Accurate calculation of the number of radiator sections
We determine the required heat output of the radiator using the formula
Qt \u003d 100 watt / m2 x S (rooms) m2 x q1 x q2 x q3 x q4 x q5 x q6 x q7
Where the following coefficients are taken into account:
Glazing type (q1)
- Triple glazing q1=0.85
- Double glazing q1=1.0
- Conventional (double) glazing q1=1.27
Wall insulation (q2)
- High-quality modern insulation q2=0.85
- Brick (in 2 bricks) or insulation q3= 1.0
- Poor insulation q3=1.27
The ratio of window area to floor area in the room (q3)
- 10% q3=0.8
- 20% q3=0.9
- 30% q3=1.0
- 40% q3=1.1
- 50% q3=1.2
Minimum outdoor temperature (q4)
- -10С q4=0.7
- -15С q4=0.9
- -20С q4=1.1
- -25C q4=1.3
- -35С q4=1.5
Number of outer walls (q5)
- One (usually) q5=1.1
- Two (corner apartment) q5=1.2
- Three q5=1.3
- Four q5=1.4
Type of room above settlement (q6)
- Heated room q6=0.8
- Heated attic q6=0.9
- Cold attic q6=1.0
Ceiling height (q7)
- 2.5m q7=1.0
- 3.0m q7=1.05
- 3.5m q7=1.1
- 4.0m q7=1.15
- 4.5m q7=1.2
Calculation example:
100 W/m2*18m2*0.85 (triple glazing)*1 (brick)*0.8
(2.1 m2 window/18m2*100%=12%)*1.5(-35)*
1.1(one outdoor)*0.8(heated apartment)*1(2.7m)=1616W
Poor thermal insulation of the walls will increase this value to 2052 W!
number of heating radiator sections: 1616W/170W=9.51 (10 sections)
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 the cold season it properly heats the room and does not have to think about installing additional portable heaters that will increase the cost of heating.
SNiP and basic regulations
Today you can name a huge number of SNiPs that describe the rules for the design and operation of heating systems in various rooms. But the most understandable and simple is the document "Heating, ventilation and air conditioning" under the number 2.04.05.
It details the following sections:
- General provisions regarding the design of heating systems
- Rules for the design of heating systems for buildings
- Features of the heating system
It is also necessary to install heating radiators in accordance with SNiP number 3.05.01. He prescribes the following installation rules, without which the calculations of the number of sections will be ineffective:
- The maximum width of the radiator should not exceed 70% of the similar characteristic of the window opening under which it is installed.
- The radiator must be mounted in the center of the window opening (a slight error is allowed - no more than 2 cm)
- The recommended space between the radiators and the wall is 2-5 cm
- Above the floor height should not be more than 12 cm
- Distance to the window sill from the top of the battery - at least 5 cm
- 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 circulate freely 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 very simple:
- Determining the need for heat
- 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 figure is very relative. If the walls and floor are poorly insulated, it is recommended to increase this value to 47-50 W, because part of the heat will be lost. In situations where a high-quality heat insulator has already been laid on the surfaces, high-quality PVC windows have been installed and drafts have been eliminated, this indicator can be taken equal to 30-34 W.
If heating is located in the room, the heat demand must be increased to 20%. Part of the thermally heated air masses will not pass through the screen, circulating inside and cooling down quickly.
Formulas for calculating the number of sections by room volume, with an example
Having decided on the need for one cube, you can begin to calculate (example on specific numbers):
- At the first step, we calculate the volume of the room using a simple formula: [height length Width] (3x4x5=60 cubic meters)
- The next step is to determine the heat demand for the particular room under consideration according to the formula: [volume]*[need per m3] (60х41=2460 W)
- You can determine the desired number of ribs using the formula: (2460/170=14.5)
- Rounding is recommended to be done 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. Therefore, the power of the ribs will be lower than the specified limit value (it is what is prescribed in the passport). If there is no minimum power indicator, then the available one is underestimated by 15-25% to simplify calculations.
Calculation by area
The previous calculation method is an excellent solution for rooms with a height of more than 2.7 m. In rooms with lower ceilings (up to 2.6 m), you can use a different method, taking the area as a basis.
In this case, calculating the total amount of thermal energy, the need for one square. m. take equal to 100 watts. There is no need to make any adjustments to it.
Formulas for calculating the number of sections by area of the room, with an example
- At the first stage, the total area of \u200b\u200bthe room is determined: [length Width] (5х4=20 sq.m.)
- The next step is to determine the heat required to heat the entire room: [area]* [need per sq. m.] (100x20=2000W)
- In the passport attached to the heating radiator, you need to find out the power of one section - the average of modern models is 170 W
- To determine the required number of sections, use the formula: [total heat demand]/[capacity of one section] (2000/170=11.7)
- We introduce correction factors ( discussed further)
- Rounding is recommended to be done 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 thermal power 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 square meters. 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 be distributed throughout the room more evenly.
If there are two window openings in the room, heating radiators should be placed under each of them. They should be 1.7 times more than the nominal power determined in the calculations.
Having bought stamped radiators, in which sections cannot be divided, it is necessary to take into account the total power of the product. If it is not enough, you should consider buying a second battery of the same or slightly less heat capacity.
Correction factors
Many factors can influence the final result. 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
- Bottom-wired manifolds - multiplying factor 1.2
- Reserve in case of unforeseen situations - increasing factor 1.2
- Use of improved thermal insulation materials - reduction factor 0.85
- Installation of high-quality heat-insulating double-glazed windows - reducing factor 0.85
The number of adjustments to be made to the calculation can be huge and depends on each specific situation. However, it should be remembered that it is much easier to reduce the heat transfer of a heating radiator than to increase it. Therefore, all rounding is done up.
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 specialists. The most accurate methods, which are described in specialized literature, take into account not only the volume or area of the room, but also the temperature outside and inside, the thermal conductivity of the various materials from which the house box is built, and many other factors.
Of course, you can not be afraid and throw a few edges to the result. But an excessive increase in all indicators can lead to unjustified expenses, which are not immediately, sometimes and not always, possible to recoup.
