Calculation of heating by area

When replacing batteries or switching to individual heating in an apartment, the question arises of how to calculate the number of radiators and the number of appliance sections. If the battery power is insufficient, it will be cool in the apartment during the cold season. An excessive number of sections not only leads to unnecessary overpayments - with a heating system with a single-pipe wiring, residents of the lower floors will be left without heat. The optimal power and the number of radiators can be calculated based on the area or volume of the room, taking into account the characteristics of the room and the specifics of different types of batteries.

Area calculation

The most common and simple technique is the method of calculating the power of devices required for heating, according to the area of ​​the heated room. According to the average norm, for heating 1 sq. Km. square meter requires 100 watts of thermal power. As an example, consider a room with an area of ​​15 square meters. meters. According to this method, 1500 W of thermal energy will be required to heat it.

When using this technique, you need to consider several important points:

• rate of 100 watts per 1 square. square meter refers to the average climatic zone, in the southern regions for heating 1 square. a meter of room requires less power - from 60 to 90 watts;
• for areas with harsh climates and very cold winters to heat 1 sq. km. meters required from 150 to 200 watts;
• the method is suitable for rooms with a standard ceiling height not exceeding 3 meters;
• the method does not take into account heat loss, which will depend on the location of the apartment, the number of windows, the quality of insulation, the material of the walls.

The calculation method for the volume of the room

The calculation method taking into account the volume of the ceiling will be more accurate: it takes into account the height of the ceilings in the apartment and the material from which the external walls are made. The sequence of calculations will be as follows:

1. The volume of the room is determined, for this room area multiplied by the height of the ceiling. For a room of 15 square meters. m. and a ceiling height of 2.7 m, it will be equal to 40.5 cubic meters.
2. Depending on the material of the walls, a different amount of energy is spent on heating one cubic meter of air. According to the norms of SNiP for an apartment in a brick house, this figure is 34 watts, for a panel house - 41 watts. So, the resulting volume must be multiplied by 34 or 41 watts. Then for a brick building to heat a room of 15 squares, 1377 W (40.5 * 34) will be required, for a panel building - 1660.5 W (40.5 * 41).

Adjustment of Results

Any of the selected methods will show only an approximate result if all factors affecting the decrease or increase in heat loss are not taken into account. For an accurate calculation, it is necessary to multiply the obtained value of the power of the radiators by the coefficients below, among which you need to choose the appropriate ones.

Window

Depending on the size of the windows and the quality of insulation through them, the room may lose 15–35% of heat. Therefore, for calculations we will use two coefficients related to windows.

The ratio of the area of ​​windows and floor in the room:

• 10% - coefficient 0.8;
• 20% – 0,9;
• 30% – 1,0;
• 40% – 1,1;
• 50% – 1,2.

Type of glazing:

• for a window with a three-chamber double-glazed window or a two-chamber with argon - 0.85;
• for a window with a conventional two-chamber double-glazed window - 1.0;
• for frames with conventional double glazing - 1.27.

Walls and ceiling

Heat loss depends on the number of external walls, the quality of thermal insulation and on which room is located above the apartment. To account for these factors, 3 more factors will be used.

The number of exterior walls:

• no external walls, no heat loss - coefficient 1.0;
• one outer wall - 1.1;
• two - 1.2;
• three - 1.3.

Thermal insulation coefficient:

• normal thermal insulation (wall with a thickness of 2 bricks or a layer of insulation) - 1.0;
• high degree of thermal insulation - 0.8;
• low - 1.27.

Accounting for the type of upper room:

• heated apartment - 0.8;
• heated attic - 0.9;
• cold attic - 1.0.

Ceiling height

If you used the method of calculating the area for a room with a non-standard wall height, then you will have to take it into account to clarify the result. The coefficient can be found out as follows: divide the existing ceiling height by the standard height, which is 2.7 meters. Thus we get the following numbers:

• 2.5 meters - a coefficient of 0.9;
• 3.0 meters - 1.1;
• 3.5 meters - 1.3;
• 4.0 meters - 1.5;
• 4.5 meters - 1.7.

Climatic conditions

The last coefficient takes into account the outdoor temperature in winter. We will build on the average temperature in the coldest week of the year.

• -10 ° C - 0.7;
• -15 ° C - 0.9;
• -20 ° C - 1.1;
• -25 ° C - 1.3;
• -35 ° C - 1.5.

Calculation of the number of sections of radiators

After we know the power required to heat the room, we can calculate the heating batteries.

In order to calculate the number of sections of the radiator, you need to divide the calculated total power by the power of one section of the device. For calculations, you can use the average statistics for different types of radiators with a standard axial distance of 50 cm:

• for cast iron batteries, the approximate power of one section is 160 W;
• for bimetallic - 180 watts;
• for aluminum - 200 watts.

Reference: the axial distance of the radiator is the height between the centers of the holes through which the coolant is supplied and removed.

For example, we determine the required number of sections of a bimetallic radiator for a room of 15 square meters. m. Suppose that you considered power the simplest way in terms of floor space. We divide the required power for its heating of 1500 watts by 180 watts. We round the resulting number 8.3 - the required number of sections of the bimetallic radiator is 8.

Important! If you decide to choose batteries of a non-standard size, find out the power of one section from the passport of the device.

The temperature dependence of the heating system

The power of the radiators is indicated for a system with a high-temperature thermal regime. If the heating system of your house operates in medium or low temperature thermal mode, additional calculations will have to be made to select the batteries with the required number of sections.

First, we determine the thermal pressure of the system, which is the difference between the average temperature of the air and the batteries. The temperature of the heating devices is taken as the arithmetic average of the values ​​of the temperature of the supply and removal of coolant.

1. High temperature: 90/70/20 (flow temperature - 90 ° C, return temperature –70 ° C, the average room temperature is set to 20 ° C). The thermal head is calculated as follows: (90 + 70) / 2 - 20 = 60 ° C;
2. Medium temperature: 75/65/20, thermal pressure - 50 ° C.
3. Low temperature: 55/45/20, thermal pressure - 30 ° C.

To find out how many battery sections you will need for systems with a heat head of 50 and 30, you need to multiply the total power by the passport head of the radiator, and then divide by the existing heat head. For a room of 15 sq.m. 15 sections of aluminum radiators, 17 - bimetallic and 19 - cast-iron batteries will be required.

For a heating system with a low temperature mode, you will need 2 times more sections.