The efficiency of a radiator directly depends on the number of sections used in it. Bimetallic battery manufacturers produce radiators with different number of sections... A wide range of radiators allows you to cover the needs of all developers without exception. The review will tell you about calculation of the number of sections of bimetallic heating radiators.
Some bimetallic battery manufacturers have gone even further. Instead of assembled radiators, they offer sections by the piece... These are the so-called freely configurable radiators. Such batteries allow you to quickly adapt radiators to the characteristics of apartments or boiler equipment.
It should be noted that most of the bimetallic batteries are sold set of 10 sections... If necessary, the number of sections can be reduced or, on the contrary, added. But if you add sections, you will have to buy the same set of 10 sections, which is not always profitable from the financial point of view. How to determine how many sections of a bimetallic radiator are needed.
Section calculation (basic formula)
Before direct installation of the batteries, you need to calculate the heat output of the radiators. This parameter is determined by the number of sections. The more sections are involved in the battery, the stronger the heat transfer will be. Of course, with an increase in the number of sections, the cost of the radiator also increases.
The number of sections is not taken from the ceiling. This parameter calculated according to certain formulas.
Basic calculation formula looks like this: W \u003d 100 * S / P, where W is the number of sections (pcs), 100 is the recommended power for 1 square meter (W), S is the area of \u200b\u200bthe heated room (m2), P is the thermal power of each section ( Tue).
We will give an example of calculation for an apartment with an area of \u200b\u200b25 (m2), provided that batteries with a thermal power of 175 (W) will be installed for each section. W \u003d 100 * 25/175 \u003d 2500/175 \u003d 14.29 (pcs). Round the value to 14 sections.
Please note that for more or less spacious rooms for which it is recommended to use more than 10 sections, it is highly desirable to use more than one radiator, but a larger number of batteries. For example, in this case, when it is necessary to use 14 sections, it is most advisable to mount 2 radiators with 7 sections each.
Regarding the optimal number of sections in the radiator, if we are talking about the battery under the window opening, then the width of the radiator should occupy 2/3 of the width of the window opening. Roughly speaking, this will be 7-8 sections of a bimetallic radiator.
Why is the above formula considered basic. The calculation is relevant only for rooms with a standard ceiling height (about 2.5-3 meters). If a calculation is made for rooms with a non-standard ceiling height, then a different formula is used. It is described below.
Calculation of sections by the volume of the room
If you are not guided by the standard ceiling height, then the volume of the room should be taken into account. According to the SNIP regulatory framework, for each cubic meter of the room, it is necessary to use 41 (W) thermal energy.
Suppose you are calculating the thermal output of batteries for a production workshop or repair shop. The area of \u200b\u200bthe room is 100 (m2), and the ceiling height is 5 (m). It is assumed that bimetallic batteries with a thermal energy of each section of 200 (W) will be used. The calculation is made as follows: S * H \u200b\u200b* 41/200, where S * H \u200b\u200bis the volume of the room (the product of the area by the height), 41 is the thermal energy for each cubic meter of the apartment volume, 200 is the thermal power of one radiator section.
100 * 5 * 41/200 \u003d 500 * 41/200 \u003d 20500/200 \u003d 102.5 (pcs). Round the value to 103 sections.
It should be noted separately that the value of the optimal heat output for each cubic meter of the room is standard. If heating is installed on the territory of an object with sealed metal-plastic double-glazed windows, then for each cubic meter of heated air it is necessary to use 34 (W) thermal energy, instead of 41 (W).
Taking into account the correction for energy efficiency, we get the following: 100 * 5 * 34/200 \u003d 85 sections.
Calculation of high-precision sections for household and administrative facilities
Speaking for the installation of heating on the territory of residential and administrative facilities, there is a more accurate formula than the basic calculation of sections.
Formula for accurate calculation of sections has the form: 100 * S * ((K1 + K2 + K3 + K4 + K5 + K6 + K7) / 7) / P, where 100 is the optimal heat output for one square meter of the room, K1 is the glazing correction factor:
- For ordinary double glass - 1.27
- For double glazing - 1.0
- For triple glazing - 0.85
K2 - correction factor for thermal insulation of walls:
- Standard thermal insulation - 1.27
- Improved thermal insulation - 1.0
- Good thermal insulation - 0.85
K3 - coefficient of correction for the ratio of window area to floor area:
50% – 1,2
- 40% – 1,1
- 30% – 1,0
- 20% – 0,9
- 10% – 0,8
K4 - coefficient of correction for temperature in the coldest season:
- -35 ⁰С - 1.5
- -25 ⁰С - 1.3
- -20 ⁰С - 1.1
- -15 ⁰С - 0.9
- -10 ⁰С - 0.7
K5 - correction factor for the number of external walls:
- one wall - 1.1
- two walls - 1.2
- three walls - 1.3
- four walls - 1.4
K6 - the correction factor for the type of room is higher:
- cold attic - 1.0
- heated attic - 0.9
- heated living quarters - 0.8
K7 - correction factor for ceiling height:
- 2.5 (m) - 1.0
- 3.0 (m) - 1.05
- 3.5 (m) - 1.1
- 4.0 (m) - 1.15
- 4.5 (m) - 1.2
7 - the number of correction factors.
P - thermal power of each section (W).
Let's make a calculation using a more accurate formula. Recall that using the basic calculation formula, we got a value of 14 sections. This is provided that the area of \u200b\u200bthe room is 25 (m2), and the power of one section of the bimetallic radiator is 175 (W).
An example of an accurate calculation: 100 * 25 * ((1 + 1 + 1.2 + 1.3 + 1.2 + 1 + 1.05) / 7) / 175 \u003d 15.81 (pcs). Round up to 16 sections.
Please note that in this case it is advisable to use 2 radiators with 8 sections each. If the room has 1 window opening, then one of the batteries must be located under the window... The radiator located under the window acts as a stationary heat curtain. If indoors 2 windows, then both radiators are mounted under the window openings.
When modernizing the heating system, in addition to replacing pipes, radiators are also changed. And today they are made of different materials, different shapes and sizes. Equally important, they have different heat dissipation: the amount of heat that can be transferred to the air. And this must be taken into account when calculating the radiator sections.
The room will be warm if the amount of heat that goes away is compensated. Therefore, the calculations are based on the heat loss of the premises (they depend on the climatic zone, on the wall material, insulation, window area, etc.). The second parameter is the thermal power of one section. This is the amount of heat that it can give out at the maximum system parameters (90 ° C inlet and 70 ° C out). This characteristic is necessarily indicated in the passport, often present on the packaging.
We do the calculation of the number of sections of heating radiators with our own hands, we take into account the features of the premises and the heating system
One important point: when doing the calculations yourself, keep in mind that most manufacturers indicate the maximum figure they received under ideal conditions. Therefore, make any rounding up. In the case of low-temperature heating (the temperature of the heating medium at the inlet is below 85 ° C), they search for the heat output for the corresponding parameters or do a recalculation (described below).
Area calculation
This is the simplest technique that allows you to roughly estimate the number of sections required to heat a room. On the basis of many calculations, the norms for the average heating power of one square of the area were derived. To take into account the climatic features of the region, two norms were prescribed in SNiP:
- for regions of central Russia, from 60 W to 100 W is required;
- for areas above 60 °, the heating rate per square meter is 150-200 W.
Why is there such a wide range in the norms? In order to be able to take into account the materials of the walls and the degree of insulation. For concrete houses, the maximum values \u200b\u200bare taken, for brick houses, you can use the average. For insulated houses - the minimum. Another important detail: these standards are calculated for an average ceiling height - no higher than 2.7 meters.
Knowing the area of \u200b\u200bthe room, you multiply its heat consumption rate, which is most suitable for your conditions. You get the general heat loss of the room. In the technical data for the selected radiator model, find the heat output of one section. Divide the total heat loss by the power, you get their amount. It is not difficult, but to make it clearer, let's give an example.
An example of calculating the number of radiator sections by the area of \u200b\u200bthe room
Corner room 16 m 2, in the middle lane, in a brick house. Batteries with a thermal power of 140 watts will be installed.
For a brick house, we take heat loss in the middle of the range. Since the room is angular, it is better to take a higher value. Let it be 95 watts. Then it turns out that 16 m2 * 95 W \u003d 1520 W is required to heat the room.
Now we count the number of radiators for heating this room: 1520 W / 140 W \u003d 10.86 pcs. Round off, it turns out 11 pieces. So many radiator sections will need to be installed.
The calculation of radiators per area is simple, but far from ideal: the height of the ceilings is not taken into account at all. With a non-standard height, a different technique is used: by volume.
We count batteries by volume
There are norms in SNiP for heating one cubic meter of premises. They are given for different types of buildings:
- for brick for 1 m 3, 34 W of heat is required;
- for panel - 41 W
This calculation of radiator sections is similar to the previous one, only now we do not need an area, but the volume and norms are different. The volume is multiplied by the norm, the resulting figure is divided by the power of one section of the radiator (aluminum, bimetallic or cast iron).
The formula for calculating the number of sections by volume
Sample calculation by volume
For example, let's calculate how many sections are needed in a room with an area of \u200b\u200b16 m 2 and a ceiling height of 3 meters. The building is brick built. Let's take radiators of the same power: 140 W:
- Find the volume. 16 m 2 * 3 m \u003d 48 m 3
- We consider the required amount of heat (the norm for brick buildings is 34 W). 48 m 3 * 34 W \u003d 1632 W.
- We determine how many sections are needed. 1632W / 140W \u003d 11.66 pcs. Round off, we get 12 pieces.
Now you know two ways to calculate the number of radiators per room.
Heat transfer of one section
Today the range of radiators is large. With the external similarity of the majority, thermal performance can differ significantly. They depend on the material from which they are made, on the size, wall thickness, internal section and on how well thought out the design.
Therefore, it is possible to say exactly how many kW in 1 section of an aluminum (cast iron bimetallic) radiator can be said only in relation to each model. This data is indicated by the manufacturer. After all, there is a significant difference in size: some of them are tall and narrow, others are low and deep. The power of a section of the same height of the same manufacturer, but different models, may differ by 15-25 W (see the table below for STYLE 500 and STYLE PLUS 500). Even more tangible differences can be from different manufacturers.
Nevertheless, for a preliminary estimate of how many battery sections are needed for space heating, the average values \u200b\u200bof the heat output for each type of radiator were derived. They can be used for approximate calculations (data are given for batteries with a center distance of 50 cm):
- Bimetallic - One section emits 185 W (0.185 kW).
- Aluminum - 190 W (0.19 kW).
- Cast iron - 120 W (0.120 kW).
More precisely, how many kW in one section of a bimetallic, aluminum or cast iron radiator you can when you choose a model and decide on the dimensions. The difference in cast iron batteries can be very big. They are with thin or thick walls, due to which their thermal power significantly changes. Above are the average values \u200b\u200bfor batteries of the usual shape (accordion) and those close to it. Radiators in the "retro" style have a significantly lower heat output.
These are the technical characteristics of the Turkish company Demir Dokum cast iron radiators. The difference is more than substantial. It can be even more
Based on these values \u200b\u200band average norms in SNiP, the average number of radiator sections per 1 m 2 was derived:
- the bimetallic section will heat 1.8 m 2;
- aluminum - 1.9-2.0 m 2;
- cast iron - 1.4-1.5 m 2;
- bimetallic 16 m 2 / 1.8 m 2 \u003d 8.88 pcs, round up - 9 pcs.
- aluminum 16 m 2/2 m 2 \u003d 8 pcs.
- cast iron 16 m 2 / 1.4 m 2 \u003d 11.4 pieces, round up - 12 pieces.
These calculations are only approximate. According to them, you can roughly estimate the cost of purchasing heating devices. You can accurately calculate the number of radiators per room by choosing a model, and then recalculating the number depending on the temperature of the coolant in your system.
Calculation of radiator sections depending on real conditions
Once again, we draw your attention to the fact that the thermal power of one battery section is indicated for ideal conditions. The battery will give out so much heat if its coolant at the entrance has a temperature of + 90 ° C, at the exit + 70 ° C, while the room is maintained at + 20 ° C. That is, the temperature head of the system (also called "system delta") will be 70 ° C. What to do if your system does not have higher than + 70 ° C at the entrance? or is the room temperature + 23 ° C required? Recalculate the declared capacity.
To do this, you need to calculate the temperature head of your heating system. For example, at the supply you have + 70 ° C, at the outlet + 60 ° C, and in the room you need a temperature of + 23 ° C. We find the delta of your system: this is the arithmetic average of the temperatures at the inlet and outlet, minus the temperature in the room.
For our case, it turns out: (70 ° C + 60 ° C) / 2 - 23 ° C \u003d 42 ° C. The delta for these conditions is 42 ° C. Next, we find this value in the conversion table (located below) and multiply the declared power by this coefficient. We will teach the power that this section can give for your conditions.
When recalculating, we proceed in the following order. Find in the blue colored columns a line with a delta of 42 ° C. It has a coefficient of 0.51. Now we calculate the thermal power of 1 section of the radiator for our case. For example, the declared power is 185 W, applying the found coefficient, we get: 185 W * 0.51 \u003d 94.35 W. Almost two times less. It is this power that needs to be substituted when calculating the radiator sections. Only taking into account individual parameters will the room be warm.
Bimetal radiators, consisting of steel and aluminum parts, are most often purchased as a replacement for failed cast iron batteries. Outdated models of heating devices cannot cope with their main task - good heating of the room. In order for the purchase to be meaningful, you need to make the correct calculation of the sections of bimetallic heating radiators for the area of \u200b\u200bthe apartment. How to do it? There are several ways.
Simple and fast calculation method
Before you start replacing old batteries with new radiators, you need to make the correct calculations. All calculations are carried out on the basis of such considerations:
- Keep in mind that the heat transfer of a bimetallic radiator will be slightly higher than that of a cast iron counterpart. With a high-temperature heating system (90 ° C), the average indicators will be 200 and 180 W, respectively;
- It's okay if the new heater heats up a little more powerfully than the old one, it's worse when it's the other way around;
- Over time, the efficiency of heat transfer will decrease slightly due to blockages in the pipes in the form of deposits of products of active interaction of water and metal parts.
From all that has been written above, one conclusion can be drawn - the number of sections for a new bimetallic radiator should be no less than that of a cast iron one. In practice, it usually happens that the battery is installed literally 1-2 sections more - this is the necessary margin, which will not be superfluous, given the last item in the list above.
Calculating power by room size
It doesn't matter if you decide to install radiators in a completely new apartment, or if you are replacing old items left over from Soviet times, you need to calculate the sections of bimetallic radiators. So, what computational methods are there to find the right battery power? Taking into account the dimensions of the apartment, calculations are made taking into account either the area or the volume. The last option is more accurate, but first things first.
The sanitary standards in force throughout Russia determine the minimum power values \u200b\u200bfor heating devices per 1 square meter of dwelling. This value is equal to 100 W (in conditions of central Russia).
The calculation of bimetallic heating radiators per square meter of the room is very simple. Measure the length and width of the room with a tape measure and multiply the resulting values. Multiply the resulting number by 100 W and divide by the heat transfer value for one section.
For example, let's take a 3x4 m room, this is a small room, and very powerful heaters are not needed here. Here is the calculation formula: K \u003d 3x4x100 / 200 \u003d 6. In the above example, a value of 200 W is taken for the heat transfer of 1 battery section.
- the results will be close to maximum accuracy only if the calculations are carried out for a room with ceilings not higher than 3 meters;
- this calculation does not take into account important factors - the number of windows, the size of doorways, the presence of insulation in the floor and walls, the material of the walls, etc.;
- the formula is not suitable for places with extremely low temperatures in winter, for example, for Siberia and the Far East.
The calculations of the sections will be more accurate if all three dimensions are taken into account in the calculations - the length, width and height of the room, in other words, you need to calculate the volume. The calculation is carried out according to a similar algorithm, as in the previous case, but other values \u200b\u200bshould be taken as a basis. The sanitary standards established for heating per 1 cubic meter are 41 W.
- The volume of the room is: V \u003d 3x4x2.7 \u003d 32.4 m3
- The battery power is calculated according to the formula: P \u003d 32.4x41 \u003d 1328.4 watts.
- Calculation of the number of cells, formula: K \u003d 1328.4 / 20 \u003d 6.64 pcs.
The number obtained as a result of calculations is not an integer, therefore it must be rounded up - 7 pieces. Comparing the values, it is easy to find that the latter method is more accurate and more efficient than calculating battery sections by area.
How to calculate heat loss
A more accurate calculation will require taking into account one of the unknowns - the walls. This is especially true for corner rooms. Let's say that the room has the following parameters: height - 2.5 m, width - 3 m, length - 6 m.
In this case, the object of the calculation is the outer wall. Calculations are made according to the formula: F \u003d a * h.
- F - wall area;
- a - length;
- h - height;
- unit of account - meter.
- According to calculations, it turns out F \u003d 3x2.5 \u003d 7.5 m2. The area of \u200b\u200bthe balcony doors and windows is subtracted from the total wall area.
- The area has been found, it remains to calculate the heat loss. Formula: Q \u003d F * K * (tvn + tnar).
- F - wall area (m2);
- K is the coefficient of thermal conductivity (its value can be found in SNiPs, for these calculations the value of 2.5 (W / square meter) was taken.
Q \u003d 7.5x2.5x (18 + (- 21)) \u003d 56.25. The result obtained is added to the rest of the heat loss values: Qroom. \u003d Qwalls + Qwindows + Qdoors. The final number obtained during the calculations is simply divided by the heat output of one section.
Formula: Qroom / Nsections \u003d number of battery sections.
Correction factors
All of the above formulas are accurate only for the middle zone of the Russian Federation and interior premises with average insulation values. In reality, absolutely identical rooms do not exist, in order to get the most accurate calculation, it is necessary to take into account the correction factors by which the result obtained by the formulas should be multiplied:
- corner rooms - 1.3;
- Far North, Far East, Siberia - 1.6;
- take into account the place where the heating device will be installed, decorative screens and boxes hide up to 25% of the thermal power, and if the battery is also in a niche, then add an additional 7% to the energy losses;
- the window requires an increase of 100 watts of power, and the doorway requires 200 watts.
For a country house, the result obtained during the calculations is additionally multiplied by a factor of 1.5 - the attic without heating and the outer walls of the building are taken into account. However, bimetal batteries are more often installed in apartment buildings than in private ones due to their high cost, especially compared to batteries made of aluminum.
Accounting for effective power
Another parameter cannot be discounted when calculating about radiators. The attached documents to the heater indicate the battery power values \u200b\u200bdepending on the type of heating system. When choosing radiators, take into account the thermal head - roughly speaking, this is the temperature regime of the coolant supplied to the system that heats the house.
In documents for a heater, a power for a head of 60 ° C is often found, this value corresponds to a high-temperature heating mode - 90 ° C (the temperature of the water supplied to the pipes). This is true for old houses with systems that were in place in Soviet times. In modern new buildings, heating technologies of a different plan and such high temperatures of the coolant in the pipes are no longer required for full heating. The thermal head in new houses is significantly lower - 30 and 50 ° С.
To calculate bimetallic heating radiators for an apartment, you need to make simple calculations: multiply the power calculated according to the previous formulas by the value of the real thermal head and divide the resulting number by the value indicated in the data sheet. As a rule, with such calculations, the effective power of the radiators is reduced.
Take this into account when calculating - in all formulas, substitute the value of the effective power that corresponds to the real thermal pressure in the heating system of your house.
When making calculations, be guided by a simple, but important rule - it is better to make a mistake in a slightly larger direction than to endure the cold due to errors in calculations. Russian winters are unpredictable and can be record-breaking frosty even in the middle zone of the country, so a small stock of 10% will not be superfluous. To regulate the heat supply, install two taps - one for the bypass, and the second for shutting off the coolant supply. By adjusting the taps, you can control the room temperature.
Outcome
So, in order to carry out all the necessary calculations and choose a radiator of the power suitable for your home, use the given calculation formulas, they are simple and fairly accurate. The main nuance is the exact value of the real power of your heating system. Spending a little time with a calculator in your hands, you will avoid mistakes when buying a heating device, and in the winter time, a comfortable temperature will be constantly maintained in your house.
Here you will learn about the calculation of sections of aluminum radiators per square meter: how many batteries are needed for a room and a private house, an example of calculating the maximum number of heaters per required area.
It is not enough to know that aluminum batteries have a high level of heat transfer.
Before installing them, it is imperative to calculate how much of them should be in each separate room.
Only knowing how many aluminum radiators are needed for 1 m2, you can confidently buy the required number of sections.
Calculation of sections of aluminum radiators per square meter
As a rule, manufacturers have calculated in advance the power standards for aluminum batteries, which depend on parameters such as ceiling height and room area. So it is believed that in order to heat 1 m2 of a room with a ceiling up to 3 m in height, a thermal power of 100 W will be required.
These figures are approximate, since the calculation of aluminum heating radiators by area in this case does not provide for possible heat loss in the room or higher or lower ceilings. These are generally accepted building codes that manufacturers indicate in the data sheets of their products.
Except them:
How many sections of an aluminum radiator do you need?
The calculation of the number of sections of an aluminum radiator is made in a shape suitable for any type of heater:
Q \u003d S x100 x k / P
In this case:
- S - the area of \u200b\u200bthe room where the installation of the battery is required;
- k - coefficient of correction of the indicator 100 W / m2, depending on the height of the ceiling;
- P - the power of one radiator element.
When calculating the number of sections of aluminum heating radiators, it turns out that in a room with an area of \u200b\u200b20 m2 with a ceiling height of 2.7 m for an aluminum radiator with a capacity of one section of 0.138 kW, 14 sections will be required.
Q \u003d 20 x 100 / 0.138 \u003d 14.49
In this example, the coefficient is not applied, since the ceiling height is less than 3 m. But even such sections of aluminum heating radiators will not be correct, since the possible heat loss of the room is not taken into account. It should be borne in mind that depending on how many windows there are in the room, whether it is corner and whether it has a balcony: all this indicates the number of sources of heat loss.
When calculating aluminum radiators by the area of \u200b\u200bthe room, the percentage of heat loss should be taken into account in the formula, depending on where they will be installed:
- if they are fixed under the windowsill, then the losses will be up to 4%;
- installation in a niche instantly increases this figure to 7%;
- if the aluminum radiator for beauty is covered with a screen on one side, then the losses will amount to 7-8%;
- closed by the screen completely, it will lose up to 25%, which makes it, in principle, unprofitable.
These are not all indicators that should be taken into account when installing aluminum batteries.
Calculation example
If you calculate how many sections of an aluminum radiator are needed for a room with an area of \u200b\u200b20 m2 at a rate of 100 W / m2, then you should also make correction coefficients for heat loss:
- each window adds 0.2 kW to the indicator;
- the door "costs" 0.1 kW.
If it is assumed that the radiator will be placed under the windowsill, then the correction factor will be 1.04, and the formula itself will look like this:
Q \u003d (20 x 100 + 0.2 + 0.1) x 1.3 x 1.04 / 72 \u003d 37.56
Where:
- first indicator Is the area of \u200b\u200bthe room;
- second - standard number of watts per m2;
- third and fourth indicate that the room has one window and one door;
- next indicator Is the level of heat transfer from the aluminum radiator in kW;
- sixth Is the correction factor for the location of the battery.
Everything should be divided into the heat dissipation of one heater rib. It can be determined from the table from the manufacturer, which indicates the heating coefficients of the media in relation to the power of the device. The average for one rib is 180 W, and the adjustment is 0.4. Thus, multiplying these numbers, it turns out that 72 W is given by one section when heating water to +60 degrees.
Since rounding is done upwards, the maximum number of sections in an aluminum radiator specifically for this room will be 38 fins. To improve the performance of the structure, it should be divided into 2 parts with 19 ribs each.
Calculation by volume
If you make such calculations, you will need to refer to the standards established in SNiP. They take into account not only the indicators of the radiator, but also the material from which the building is built.
For example, for a brick house, the norm for 1 m2 will be 34 W, and for panel buildings - 41 W. To calculate the number of battery sections by the volume of the room, you should: the volume of the room is multiplied by the rate of heat consumption and divided by the heat transfer of 1 section.
For example:
- To calculate the volume of a 16 m2 room, you need to multiply this indicator by the ceiling height, for example, 3 m (16x3 \u003d 43 m3).
- Heat rate for a brick building \u003d 34 W, to find out how much is required for a given room, 48 m3 x 34 W (for a panel house of 41 W) \u003d 1632 W.
- We determine how many sections are required with a radiator power, for example, 140 watts. For this 1632 W / 140 W \u003d 11.66.
Rounding this figure, we get the result that an aluminum radiator of 12 sections is required for a room with a volume of 48 m3.
Heat output of 1 section
As a rule, manufacturers indicate average heat transfer rates in the technical characteristics of heaters. So for heaters made of aluminum, it is 1.9-2.0 m2. To calculate how many sections are required, you need to divide the area of \u200b\u200bthe room by this coefficient.
For example, for the same room with an area of \u200b\u200b16 m2, 8 sections will be required, since 16/2 \u003d 8.
These calculations are approximate and it is impossible to use them without taking into account the heat loss and the actual conditions for placing the battery, since you can get a cold room after installing the structure.
To get the most accurate indicators, you will have to calculate the amount of heat that is needed to heat a specific living area. For this, many correction factors will have to be taken into account. This approach is especially important when the calculation of aluminum heating radiators for a private house is required.
The formula required for this is as follows:
KT \u003d 100W / m2 x S x K1 x K2 x K3 x K4 x K5 x K6 x K7
If you apply this formula, you can foresee and take into account almost all the nuances that can affect the heating of the living space. Having made a calculation according to it, you can be sure that the result obtained indicates the optimal number of aluminum radiator sections for a particular room.
Whatever calculation principle is undertaken, it is important to do it as a whole, since correctly selected batteries allow you not only to enjoy the heat, but also significantly save on energy costs. The latter is especially important in the context of constantly growing tariffs.
Bimetallic radiators are most often purchased for installation in city apartments, where they replace old cast-iron batteries inherited from the times of developed socialism. In order for the new heater to heat the room no worse than its predecessor, it is necessary to ensure that its dimensions correspond to the dimensions of the existing installation space and correctly calculate the required number of sections.
The calculation of the number of sections of bimetallic radiators when replacing cast iron batteries with them can be carried out based on the following considerations:
- The heat transfer of a bimetallic battery is slightly higher than that of a cast iron battery (at a coolant temperature of 90 ° C, the average values \u200b\u200bare 200 and 180 W, respectively);
- If the new battery warms up a little better than the old one, that's pretty good;
- Over time, the efficiency of the radiators is somewhat reduced due to clogging of the inner surface by deposits of the products of interaction between the metal and the coolant.
The facts we have given indicate that the number of sections of a bimetallic radiator should be the same as that of the previous cast iron. In practice, it is often set one or two more sections to create a margin for the future, taking into account the last point of the above analysis.
Methods for assessing heat transfer by room size
If you are installing a radiator in a new room or want to check the conclusions of the previous section, you can calculate the number of sections by calculating the required heat output of the radiator.
Area calculation
There are plumbing standards that determine the minimum power of radiators for heating one square meter of living space. For central Russia, this figure is 100 watts.
We consider the area of \u200b\u200bour premises by multiplying its length and width. After that, we multiply it by 100 W and divide by the heat transfer of one section.
K \u003d 3 * 4 * 100/200 \u003d 6.
Here we took the heat transfer of the radiator section equal to 200 W.
Area calculation has several disadvantages:
- Reliable results can be obtained for rooms with a ceiling height of no more than 3 m;
- The features of the room are not taken into account: the number of windows, the degree of insulation, etc.
- The results are valid for central Russia.
Calculation by volume
A more accurate estimate can be obtained by calculating taking into account all three measurements of the heated room, i.e., its volume. The calculation algorithm here is about the same, only the data on the heating power per 1 m 3 are taken as a basis. The same standards set this value equal to 41 W.
- Room volume V \u003d 3 * 4 * 2.7 \u003d 32.4 m 3.
- Battery power P \u003d 32.4 * 41 \u003d 1328.4 W.
- Number of sections K \u003d 1328.4 / 20 \u003d 6.64.
We see that according to the volumetric method, 7 sections are needed. Therefore, we conclude that the calculation of bimetallic radiators by the volumetric method gives a more accurate result.
Correction factors
The calculation of the number of sections by the above methods is applicable for central Russia and for some generalized room with average insulation conditions. In practice, a number of correction factors are used to refine the results:
- For a corner room, the result is multiplied by 1.3;
- For different regions there are additional coefficients, for example, for the Far North it is 1.6;
- Depending on the place where the radiator is installed, additional losses must be taken into account: the decorative screen takes about 25% of the heat, and another 7% of the energy is lost in the niche under the windowsill;
- Each additional window adds another 100W and the door adds 200W.
For private houses, the result obtained must be multiplied by another 1.5. This is done to accommodate the cold attic and exterior walls. However, as we have already noted, bimetallic batteries are practically not used in private houses due to their relative high cost in comparison, for example, with aluminum radiators.
Effective battery power
It is necessary to make a number of comments regarding the radiator calculation process.
All battery power values \u200b\u200bare indicated by manufacturers for certain parameters of the heating system device. The main characteristic that must be considered when choosing bimetallic batteries is the thermal head.
Without going into technical details, let's say that the thermal head characterizes the degree of heating of the coolant and the quality of heating.
Most often, the radiator passports give the value of the section power for a thermal head of 60 ° C. It corresponds to a coolant temperature of 90 ° C. In old houses, where cast-iron batteries are still preserved in many apartments, this corresponds to reality. However, in new buildings, more modern technologies have recently been introduced, allowing the use of a less heated coolant. The thermal head in such systems can be 30 or 50 ° C.
If you need to calculate the radiator, then the power obtained by the above methods must be multiplied by the real thermal head and divided by the passport. Usually, the effective power of bimetallic radiators becomes less.
Be sure to keep in mind that when calculating the number of sections, you need to substitute in all formulas exactly the effective power, recalculated to your thermal head.
So, in order to calculate how many sections of a bimetallic radiator you need to buy, use fairly simple formulas that give a relatively accurate estimate. The only subtlety in this matter is to correctly take into account the power of the section relative to your heating system. We hope that with the help of our article you will do it right, and you will not freeze on cold dank evenings.