Despite the emergence of innovative developments, the familiar heating system using radiators has not been forgotten: it is still just as popular. The reasons for this demand are its efficiency and reliability. However, in this case, an accurate calculation is required before installation. A lack of heat generated will lead to cold in the house in winter; its excess will require frequent ventilation and high heating costs. To avoid such consequences, it is better to find out in advance how many squares 1 radiator section is designed for. There are several ways to get the desired value - the right number of them. Some of them are approximate, others can be called quite accurate.
What is heat transfer
Bimetallic heating radiator
The definition of heat transfer comes down to a couple of simple words - it is the amount of heat generated by a radiator over a certain period of time. Radiator power, thermal power, heat flow - the designation of one concept and is measured in Watts. For 1 section of a bimetallic radiator, this number is 200 W.
Heat transfer table for heating radiators
Some documents contain heat transfer values calculated in calories per hour. To avoid confusion, calories are easily converted to Watts using simple calculations (1 Watt = 859.8 cal/hour).
Heat from the battery warms the room through three processes:
- heat exchange;
- convection;
- radiation.
Room heating process
Each model of heating devices uses all types of heating, but in different proportions. For example, a radiator is considered to be those batteries that transfer 25% of thermal energy into the surrounding space through radiation. But now the term “radiator” has begun to be used to describe any heating device, regardless of the main heating method.
Dimensions and capacity of sections
Due to steel inserts, bimetallic radiators are more compact than aluminum, cast iron, and steel models. To some extent, this is not bad; the smaller the section, the less coolant is required for heating, which means that the battery is more economical in terms of heat energy consumption. However, too narrow pipes quickly become clogged with debris and rubbish, which are inevitable companions in modern heating networks.
Debris and dirt in the radiator
Good models of bimetal radiators have steel cores inside that are as thick as the walls of a regular water pipe. The heat transfer of the battery depends on the capacity of the sections, and the interaxial distance directly affects the capacity parameters:
- 20 cm - 0.1-0.16 l;
- 35 cm - 0.15-0.2 l;
- 50 cm - 0.2-0.3 l.
From the given data it follows that bimetal radiators require a small amount of coolant. For example, a heating device made of ten sections 35 cm high and 80 cm wide holds only 1.6 liters. Despite this, the heat flow is sufficient to warm the air in a room of 14 square meters. m. It is worth considering that a battery of this size weighs almost twice as much as its aluminum counterparts - 14 kg.
The vast majority of bimetal batteries can be purchased in specialized stores in one section and assembled a radiator of exactly the size required by the room. This is convenient, although there are one-piece models with a fixed number of sections (usually no more than 14 pieces). Each part has four holes: two inlets and two outlets. Their sizes may vary depending on the model of the heating device. To make it easier to assemble bimetal radiators, two holes are made with right-hand threads, and two with left-hand threads.
Assembly of bimetallic heating radiators
How to choose the right number of sections
The heat output of bimetallic heating devices is indicated in the data sheet. Based on this data, all necessary calculations are made. In cases where the heat transfer value is not indicated in the documents, these data can be viewed on the official websites of the manufacturer or used in the calculations the average value. For each individual room, its own calculation must be carried out.
To calculate the required number of bimetal sections, you need to take into account several factors. The heat transfer parameters of bimetal are slightly higher than those of cast iron (taking into account the same operating conditions. For example, let the coolant temperature be 90 ° C, then the power of one section of bimetal is 200 W, of cast iron - 180 W).
Radiator heating power calculation table
If you are planning to replace a cast-iron radiator with a bimetallic one, then with the same dimensions, the new battery will heat a little better than the old one. And this is good. It is worth considering that over time the heat transfer will be slightly less due to blockages inside the pipes. Batteries become clogged with deposits that appear due to metal contact with water.
Therefore, if you decide to replace it, then calmly take the same number of sections. Sometimes batteries are installed with a small margin in one or two sections. This is done to avoid loss of heat transfer due to clogging. But if you are purchasing batteries for a new room, you cannot do without calculations.
Video description
Additionally, see how to connect radiators to a one-pipe system:
Using old metrics
When carrying out repair work and replacing previous heating equipment, you can use the previous data. If the temperature level during the heating season is satisfactory, then the thermal power remains the same. Old batteries will lose 10-15% of their thermal conductivity over time due to internal corrosion. Therefore, the new ones will require a smaller number of sections with a similar battery material.
When installing devices in designer versions, you should approach the installation with special care. Unconventional solutions significantly change the air heating system.
Corner design Source remkasam.ru
Calculation by dimensions
The heat output of radiators depends on the volume of the room that needs to be heated. The larger the room, the more sections will be required. Therefore, the simplest calculation is based on the area of the room.
There are special standards for plumbing, strictly regulated by SNiP. Batteries are no exception. For buildings in a temperate climate zone, the standard heating power is 100 W per square meter of room. Having calculated the area of the room, multiplying the width by the length, you must also multiply the resulting value by 100. This will give you the total heat transfer of the battery. All that remains is to divide it into the heat transfer parameters of the bimetal.
Formula for calculating the number of sections according to the dimensions of the room
For a room 3x4 m, the calculation will look like this: K = 3x4x100/200 = 6 pcs. The formula is extremely simple, but allows you to calculate only the approximate number of bimetal sections. These calculations do not take into account such important parameters as:
- ceiling height (the formula is more or less accurate for ceilings no higher than 3 m);
- location of the room (north side, corner of the house);
- number of window and door openings;
- degree of insulation of external walls.
How hot should the battery get?
Design features of cast iron radiators
Cast iron radiators are the most durable.
The batteries have the most traditional appearance. The design includes several sections connected to each other by nipples. To seal the joints, heat-resistant rubber or paronite is used. The coolant channels inside have a round or elliptical cross-section. They produce one-, two- and three-channel sections.
The batteries are cast from gray cast iron. The material is wear-resistant and durable - radiators last more than 50 years. Salts are not deposited on the walls, small debris or sand does not cause damage. Even after 30–40 years, the diameter of the working channels remains almost unchanged.
The size of a cast iron battery depends on the number of sections. The size is selected based on the size of the heated room. But if the width of the product is determined by the number of elements, then the height and depth depend on the structure of the sections themselves.
The appearance of the product is unattractive. More modern models are produced with a flat front panel. Decorated with forged elements.
Calculation by volume
Calculating the heat transfer of a battery by room volume is a little more complicated. To do this, you will need to know the width, length and height of the room, as well as the heating standards established for one m3 - 41 W.
What kind of heat transfer should bimetallic radiators have for a room 3x4 m, taking into account the ceiling height of 2.7 m: V = 3x4x2.7 = 32.4 m3. Having received the volume, it is easy to calculate the heat transfer of the battery: P = 32.4x41 = 1328.4 W.
As a result, the number of sections (taking into account the thermal power of the battery at high temperature mode 200 W) will be equal to: K = 1328.4/200 = 6.64 pcs. The resulting number, if it is not an integer, is always rounded up. Based on more accurate calculations, you will need 7 sections, not 6.
Manufacturers of cast iron radiators
It is not only Russian factories and enterprises in CIS countries that produce such products. There are many foreign manufacturers offering cast iron radiators in retro or techno style. Models from domestic companies are cheaper.
Minsk Heating Equipment Plant
One of the most famous manufacturers. It produces two- and three-channel cast iron batteries in a variety of designs. There are classic radiators and models with a flat surface - they are more efficient because they transfer heat better, as well as options with a pattern on the surface. The number of sections is determined by the customer.
Santekhlit (Russia)
The plant offers classic models. The depth of sections and height varies within very wide limits. There are models with a depth of only 11 cm. They can be easily placed under a narrow modern window sill. The length of the battery is determined by the number of sections.
Correction factors
Despite the same values in the data sheet, the actual heat transfer of radiators may differ depending on operating conditions. Considering that the above formulas are accurate only for houses with average insulation rates and for areas with a temperate climate, under other conditions it is necessary to introduce amendments to the calculations.
Correction factors when calculating the number of heating radiator sections
To do this, the value obtained during the calculations is additionally multiplied by a coefficient:
- corner and northern rooms - 1.3;
- regions with extreme frosts (Far North) - 1.6;
- screen or box - add another 25%, niche - 7%;
- for each window in the room, the total heat transfer for the room increases by 100 W, for each door - 200 W;
- cottage - 1.5;
Important! The last coefficient when calculating bimetallic radiators is used extremely rarely, because such heating devices are almost never installed in private homes due to their high cost.
Bimetallic radiators
