The main methods of calculation
If you want your apartment or house to be really warm, other external factors must also be taken into account, including the thermal insulation of the room, the number of windows and doors, etc. д. However, the easiest way to determine which radiator is needed is to calculate the room dimensions.
Method By area
According to the old plumbing standards: 100 watts per 1 m 2 living space.
According to the new norms, taking into account insulation standards: 80 watts per 1 m 2 living space.
Based on this, one radiator section per 2 squares. A more accurate calculation can be obtained if you take into account the heat output of the section.
For a room of 12 m2 when installing aluminum radiators, the calculation formula will be as follows:
According to the old norms: 12 м.sqm.100 W = 1200 W
Under the new standards: 12м. sq.m.80 watts = 960 watts
For example, one radiator section gives out 186 W.
Under the old standards: 1200/186=6.46 sections we need. We recommend to take in the big side, ie, 7 sections.
According to new standards: 960/186 = 5,17 sections we need. We recommend to take a larger side, i.e. 6 sections.
Influence on the result of the material of manufacture of the radiator
Currently the most popular are the following varieties of radiators:
- Cast-iron. The most often used cast iron battery brand MS-140 with a heat emission of 180 W. This figure is true only when using the coolant with the maximum temperature. In practice this is rarely the case, so the actual wattage of the device is 60-120 W. These are the figures we recommend when performing the calculation of watts per square meter of heating.
- Steel. Have almost the same area as cast iron. The same applies to the parameters, the exact values of which are specified in the accompanying documentation. At the same time the weight of steel products is less, which makes their transportation and installation easier.
- Aluminum. To give a general answer, how much heats one section of an aluminum radiator is problematic, since such products are on sale in a large number of modifications. Therefore, in each case of calculating the number of sections of aluminum radiators should be guided by the data sheet model. In general, it is believed that the average rate, how much heats one section of aluminum radiator is 100 W/m2. If the declared power of the device is less, then most likely we are talking about a fake. It should also be said that the level of heat dissipation of aluminum is higher than that of cast iron and steel. This should also be taken into account before calculating the number of sections of aluminum heating radiators.
- Bimetallic. These products, combining a high heat output of aluminum and strength qualities of steel, are currently the most popular among buyers (the power level of one section of a bimetallic radiator is identical to how many squares one section of aluminum battery). Due to the good heat transfer, it is allowed to reduce the number of sections during installation. Proper calculation of bimetallic radiators allows to save money even despite the fact that bimetallic radiators are considered the most expensive.
Maximum values of heat output of devices is not recommended to use when calculating the sections of aluminum radiators per square meter. the coolant in the system usually never reaches extreme values. A more reliable way. to use the minimum values, which will guarantee the avoidance of errors. Equipped on the basis of the calculation of aluminum radiator sections heating system will provide comfort in the dwelling even in case of severe frosts.
Power of 1 section of bimetal heating radiators
The main task of any radiator is to heat the room. For these reasons, the heat output. the main parameter to consider when buying. For each model of radiators, the heat emission values are different, including bimetal. This parameter is influenced by the volume and number of sections.
So what is the power of 1 section of bimetallic radiators for heating? Knowing the value, you can correctly calculate the necessary size of the device.
Why do the calculation, but not choose the radiator by eye?
Note: often when buying a bimetallic device, some people are guided by how many sections were in previously operated cast-iron radiators. This approach is fundamentally wrong.
Some people decide to perform a calculation of the number of sections by eye, for example, if the cast-iron radiator had 9 of them, then choose a bimetallic radiator with 6 sections. But in the end the probability to guess is very small, and it turns out that after installing a new device in the room is either very cold, or on the contrary too hot. That is why it is better to make an accurate calculation of bimetallic radiators. Fortunately, modern manufacturers produce devices with a different number of sections and it is not difficult to pick up a model for a room with virtually any planning features.
Calculating the number of radiators
For the climatic zone of Ukraine has long been calculated the consumed heat power under standard conditions. Standard conditions include: a room with one window (usual), one door, one exterior wall. For one cubic meter of such a living space we usually take 41 W of heat power. Based on these data is not difficult to calculate the required number of sections of the radiator, knowing its heat output.
2.3 One and Two Pipe Heating Systems
For example, we can take a 5×6 m room with a standard ceiling height of 2.7 m. First you need to calculate the size of the room. So 562,7 = 81 m3. Do not forget that if the front door to the room is in the form of an arch that does not close, to the volume of the room must be added the volume of the adjacent room. When you know the volume, multiply it with 41 watts: 81 41 = 3321. The resulting number is the thermal energy needed to heat our room.
If you have already decided which radiators you will use and you know their thermal capacity, it is easy enough to calculate the number of sections. It is also possible to start from desirable number of sections, manipulating their heating power. Let’s take for example heating radiators with thermal efficiency of one section equal to 200 Watt. Divide the volume of the room by the power of one section: 3321 / 200 = 16.605. The resulting number rounded up to more, so for heating our room we need 17 sections of the radiator heating, capacity of 200 watts each. If you have installed cast-iron radiators with interaxial distance of 600 mm, and you are satisfied with the temperature in the room, but you want to replace them with new radiators you can calculate the required number of sections of new batteries. Heat output of one section of such a cast-iron radiator is 150 watts. Accordingly, 150 multiplied by the number of sections installed in your room and get the number of heating energy in your room. Starting from this number we find the above described way the number of sections of new radiators.
This simple calculation is made for the condition that the coolant temperature is not below 70 C. If the fluid temperature is lower it is worth to increase the number of sections of the radiator. Also, in the calculations, you must consider the heat loss of the room. Installation of a glazing unit will reduce the heat loss by 15-20% and installation of a decorative panel covering the radiator will reduce the heat output of the radiator by 20-30%. It is also worth considering the location of your room. Corner or not, first or last floor, and the degree of insulation of the walls.
Getting ready for winter calculation of the number of radiator sections.
There are three methods here, which are based on general principles:
- Standard value of one radiator section power can vary from 120 to 220 W, so the average value is taken
- To correct for uncertainties in the calculations when purchasing a radiator, a 20% reserve should be built in
Now let’s turn directly to the methods themselves.
The first standard method
Based on building regulations, for quality heating of one square meter you need 100 watts of radiator power. Let’s do the calculations.
Let’s say the area of the room is 30 square meters, we’ll take the power of one section to be 180 Watts, then 30100/180 = 16.6. Let’s round this value up and get that 17 radiator sections are needed for a 30 square meter room.
However, if the room is angular, then the obtained value should be multiplied by the coefficient of 1.2. In this case the number of required sections of radiators will be 20
The second approximate method
This method differs from the previous one in that it is based not only on the area of the room, but also on its height. Note that the method works only for devices of medium and high power.
At low power (50 watts or less) such calculations will be ineffective due to too big an error.
So if we assume that the average height of the room is 2,5 meters (standard ceiling height in most apartments), then one section of the standard radiator is able to heat an area of 1.8 m.
The calculation of the sections for a room of 30 “squares” will be as follows: 30/1,8=16. Let’s round up again and get that 17 heater sections are needed for heating this room.
The third volumetric method
As the name suggests, the calculations in this method are based on the volume of the room.
Assuming a space of 5 cubic metres, 1 section of 200 Watts is needed for heating. With a length of 6 m, a width of 5, and a height of 2.5 m, the formula for calculation would be as follows: (652,5)/5 =15. Consequently, for a room with these parameters you need 15 radiator sections of heating capacity of 200 watts each.
If the radiator is planned to be located in a deep open niche, the number of sections should be increased by 5%.
If you plan to completely cover the radiator with a panel, the increase should be 15%. Otherwise it will be impossible to achieve optimal heat transfer.
Read the article and find out how to build a scheme of water heating of a private house.
Here is all about how to choose a heating radiator
Calculation of aluminum radiator sections per square meter
Here you will learn about calculating the sections of aluminum radiators per square meter: how many radiators per room and private house, an example of calculating the maximum number of heaters on the necessary area.
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Not enough to know that aluminum radiators have a high level of heat dissipation.
Before installing them, it is necessary to make a calculation of exactly how many of them there should be in each individual room.
Only if you know how many aluminum radiators per square meter you can buy the right number of sections.
How many kW in one section of an aluminum radiator
The heat output of an aluminum radiator section depends on the volume of water that is in it. Standard volumes. 0.35 and 0.5 liters.
Aluminum batteries give off heat by 50-60% through radiation and 40-50% in the form of convection. Air cutoff increases convection by 20-25%, which increases heat output.
At an air temperature of 20-24 ° C and water in the circuit of 65-70 ° C, the thermal capacity of one aluminum section is:
- Volume 0,35 l., Without the cutoff. 0.1-0.12 kilowatts;
- Volume 0.35 l., with the eliminator. 0,12-0,13 kilowatt;
- 0,5 l volume., without shutoff valve. 0,155-0,170 kW;
- Volume 0.5 l., with the cutoff switch. 0.170-0.200 Kilowatt.
It is difficult to name the exact amount of heat transfer. it depends on the design features, pipe diameter, fin thickness. Performance is affected by the type of battery connection, the speed of water pumping, the dirtiness of the internal surfaces.
How to calculate correctly, how many sections of the radiators are needed per one meter per square meter
There are several available ways to calculate the volume of the radiator with the coolant:
Everyone should understand that radiators made of different materials have different efficiency in terms of heat transfer. Of course, the thermal capacity of radiators is one of the most important factors for calculations, but not decisive.
Correctly chosen radiator will provide quality heat in the house
There are different ways to calculate, to reduce the error, usually count:
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If you use the practice of heating urban apartments, taking into account the fact that for 18 “squares” of the hall uses a radiator of 10 sections, logical adjustments are made:
- In the central belt of Russia heat provides 11-12 sections per room with low ceilings, in Siberia and Trans-Urals require 14-16 on the same footprint. In the Krasnodar region in the winter is not cold, enough and 9-10 sections.
- Cast-iron radiators in 8 segments have a sufficient heat output to heat a small bedroom (120-150 watts per section). Number of sections of bimetallic radiators will be less, they have higher efficiency, aluminum radiators have lower. Accordingly, for a standard room of 18-20 square meters one needs two 8-section cast-iron radiators or one 12-piece bimetallic unit.
- Corner rooms with 1-2 external walls without internal and external insulation make adjustments. Almost half of the heat is lost, especially in a cold spell, the number of sections should be 25-30% more.
There are a number of other factors that make adjustments to the calculations:
- Type of coolant (steam, water, antifreeze);
- the number of external and internal walls;
- What the outside surface of the floor and ceiling borders with (attic, basement, living rooms);
- ceiling height (standard 2.7-3 m), there are rooms of greater volume;
- thermal conductivity of the material of pipes and batteries, which is affected even by the number of layers of paint and its type;
- thermal insulation of the walls;
- the number of windows on different sides of the world;
- the duration of the winter period (climatic index);
- the temperature amplitude in winter time;
- old wooden windows or modern double-glazed windows (the latter keep the heat in the rooms as much as possible);
- Heat loss and the type of connection of the heat carrier (bottom, saddle, diagonal, lateral top); the presence of a warm entranceway, strong ventilation, the need for frequent ventilation also affect the choice of heating system capacity.
Deciding what radiators are better for the apartment, it is preferable to choose devices that have a higher heat output
Important! A radiator that is covered by a decorative shield or screen for aesthetics or for the safety of small children reduces the heat output by 10-15%. On the contrary, the foil covering of the battery niche contributes to heat retention.