Heat consumption standard. How much heat do we need, how much heat do we pay for? Basic standards for the consumption of thermal energy for heating Heat consumption per 1 sq m

Heating installation includes, radiators, pipes, fasteners, thermostats, air vents, pressure increasing pumps, expansion tank, connection system, boiler collectors. Each factor is of great importance. Based on this, the correspondence of each part of the structure must be planned correctly. The apartment heating design includes some components. On the open page of the resource, we will try to help you choose the necessary structural units for the right house.

children's room - 10.8 m2.

and kitchen - 10.5 m2.

Note:

children's room suit in the room where the furnace doors (compartments) do not go.

To the children's room only a solid wall of the stove should come out, to prevent carbon monoxide from entering the children's room .

The figure shows a variant location multi-turn heating furnace (conditionally furnace number 1), the walls of which lead to the nursery and the living room. As well as kitchen oven (conditionally furnace number 2), the walls of which open into the bedroom and into the kitchen.

house walls we choose in the brick version.

Brick efficient (multi-hole, with slit-like voids) with a bulk density of 1300 kg / m3 - the most suitable for cold winter temperatures.

house walls made with solid masonry in cold mortar with external jointing and internal plastering.

Wall masonry thickness 510 mm.

An example of wall thickness is taken here.

Floors at home performed on logs, overlap loft wooden, window with double frames.

Permissible design (winter) temperature outside air T = -35°С.

for calculations, also use SNiP 23-01-99 "Construction climatology"

Source: http://www.energomir.su/raschet

Before the start of the heating season, the problem of good and high-quality home heating is acute. Especially if repairs are being made and batteries are changing. The range of heating equipment is quite rich. Batteries are offered in different capacities and types. Therefore, it is necessary to know the features of each type in order to correctly select the number of sections and the type of radiator.

What are heating radiators and which one should you choose?

The radiator is a heating deviceconsisting of separate sections, which are interconnected by pipes. A coolant circulates through them, which is most often plain water heated to the required temperature. First of all, radiators are used for heating residential premises. There are several types of radiators, and it is difficult to single out the best or worst. Each variety has its own advantages, which are mainly represented by the material from which the heater is made.

• Cast iron radiators. Despite some criticism of them and unfounded claims that cast iron has a weaker thermal conductivity than other varieties, this is not entirely true. Modern radiators made of cast iron have a high thermal power and compactness. In addition, they have other advantages:
  • A large mass is a disadvantage during transportation and delivery, but the weight leads to a greater heat capacity and thermal inertia.
  • In the event that there are temperature drops in the coolant in the heating system in the house, cast-iron radiators keep the heat level better due to inertia.
  • Cast iron is weakly susceptible to the quality and level of clogging of water and its overheating.
  • The durability of cast-iron batteries surpasses all analogues. In some houses, old Soviet-era batteries are still observed.

Of the disadvantages of cast iron, it is important to know about the following:

• high weight provides a certain inconvenience during maintenance and installation of batteries, and also requires reliable mounting fasteners,
• cast iron periodically needs painting,
• since the internal channels have a rough structure, plaque appears on them over time, which leads to a drop in heat transfer,
• cast iron requires a higher temperature for heating, and in case of poor supply or insufficient temperature of heated water, the batteries heat the room worse.

Another disadvantage that should be singled out separately is the tendency for the gaskets to break between the sections. According to experts, this manifests itself only after 40 years of operation, which in turn once again emphasizes one of the advantages of cast-iron radiators - their durability.

• Aluminum batteries are considered the best choice, as they have high thermal conductivity combined with a larger surface area of ​​​​the radiator due to the protrusions and fins. The following are distinguished as their advantages:
  • light weight,
  • ease of installation,
  • high working pressure,
  • small dimensions of the radiator,
  • high degree of heat transfer.

The disadvantages of aluminum radiators include their sensitivity to clogging and corrosion of metal in water, especially if the battery is exposed to small stray currents. This is fraught with an increase in pressure, which can lead to a rupture of the heating battery.

To eliminate the risk, the inside of the battery is coated with a polymer layer that can protect aluminum from direct contact with water. In the same case, if the battery does not have an inner layer, it is highly recommended not to turn off the taps with water in the pipes, as this can cause a break in the structure.

• A good choice would be to buy a bimetallic radiator, consisting of aluminum and steel alloys. Such models have all the advantages of aluminum, while the disadvantages and danger of rupture are eliminated. It should be borne in mind that their price is correspondingly higher.
• Steel radiators are available in different form factors, which will allow you to choose a device of any power. They have the following disadvantages:
  • low working pressure, as a rule, which is only up to 7 atm,
  • the maximum temperature of the heat carrier must not exceed 100°C,
  • lack of protection against corrosion,
  • weak thermal inertia,
  • sensitivity to changes in operating temperatures and hydraulic shocks.

Steel radiators are characterized by a large area of ​​the heating surface, which stimulates the movement of heated air. It is more expedient to attribute this kind of radiators to convectors. Since a steel heater has more disadvantages than advantages, if you want to buy a radiator of this type, you should first pay attention to bimetallic structures or cast-iron batteries.

• The last variety is oil coolers. Unlike other models, oil-based devices are independent of the common central heating system and are more often purchased as an additional mobile heater. As a rule, it reaches its maximum heating power already 30 minutes after heating, and in general, it is a very useful device, especially relevant in country houses.

When choosing a radiator, it is important to pay attention to their service life and operating conditions. There is no need to save money and buy cheap models of aluminum radiators without a polymer coating, as they are highly susceptible to corrosion. In fact, the most preferred option is still a cast iron radiator. Sellers tend to impose the purchase of aluminum structures, emphasizing that cast iron is outdated - but this is not so. If we compare numerous reviews by battery type, it is cast iron heating batteries that still remain the most correct investment. This does not mean that it is worth sticking to the old ribbed MS-140 models from the era of the Land of the Soviets. Today, the market offers a significant range of compact cast iron radiators. The initial price of one section of a cast-iron battery starts at $7. For lovers of aesthetics, radiators are available for sale, which are whole artistic compositions, but their price is much higher.

Required values ​​for calculating the number of heating radiators

Before proceeding with the calculation, it is necessary to know the main coefficients that are used in determining the required power.

Glazing: (k1)

• triple energy-saving double-glazed window = 0.85
• double energy saving = 1.0
• simple double-glazed window = 1.3

Thermal insulation: (k2)

• concrete slab with a 10 cm thick polystyrene layer = 0.85
• brick wall two bricks thick = 1.0
• ordinary concrete panel - 1.3

Relation to window area: (k3)

• 10% = 0,8
• 20% = 0,9
• 30% = 1,0
• 40% = 1.1 etc.

Minimum outdoor temperature: (k4)

• - 10°C = 0.7
• - 15°C = 0.9
• - 20°C = 1.1
• - 25°C = 1.3

Room ceiling height: (k5)

• 2.5 m, which is a typical apartment = 1.0
• 3 m = 1.05
• 3.5m = 1.1
• 4 m = 1.15

Heated room coefficient = 0.8 (k6)

Number of walls: (d7)

• one wall = 1.1
• corner apartment with two walls = 1.2
• three walls = 1.3
• detached house with four walls = 1.4

Now, to determine the power of radiators, you need to multiply the power indicator by the area of ​​\u200b\u200bthe room and by the coefficients according to this formula: 100 W/m2*Sroom*k1*k2*k3*k4*k5*k6*k7

There are many calculation methods, from which it is worth choosing the more convenient one. They will be discussed further.

How many radiators do you need?

There are several methods for how to calculate radiators: their number and power. It is based on the general principle of averaging the power of one section and taking into account the reserve, which is 20%

• the first method is standard, and allows you to calculate by area. For example, according to building codes, 100 watts of power is needed to heat one square meter of area. If the room has an area of ​​20 m², and the average power of one section is 170 watts, then the calculation will look like this:

20*100/170 = 11,76

The resulting value must be rounded up, so to heat one room you will need a battery with 12 radiator sections with a power of 170 watts.

• an approximate calculation method will make it possible to determine the required number of sections, based on the area of ​​\u200b\u200bthe room and the height of the ceilings. In this case, if we take as a basis the heating index of one section of 1.8 m² and the ceiling height of 2.5 m, then with the same room size, the calculation 20/1,8 = 11,11 . Rounding this figure up, we get 12 battery sections. It should be noted that this method has a larger error, so it is not always advisable to use it.
• the third method is based on calculating the volume of the room. For example, a room is 5 m long, 3.5 wide, and has a ceiling height of 2.5 m. Based on the fact that heating 5 m3 requires one section with a heat output of 200 watts, we get the following formula:

(5*3,5*2,5)/5 = 8,75

We again round up and get that to heat the room you need 9 sections of 200 watts each, or 11 sections of 170 watts.

It is important to remember that these methods have an error, so it is better to set the number of battery sections to one more. In addition, building codes require minimum indoor temperatures. If it is necessary to create a hot microclimate, then it is recommended to add at least five more sections to the resulting number of sections.

Calculation of the required power for radiators

• the size of the room is determined. For example, an area of ​​​​20 m and a ceiling height of 2.5 m:

After increasing the indicator upwards, the required radiator power value of 2100 watts is obtained. For cold winter conditions with air temperatures below -20°C, it makes sense to additionally take into account a power reserve of 20%. In this case, the required power will be 2460 watts. equipment of such thermal power should be looked for in stores.

You can also correctly calculate heating radiators using the second calculation example, based on taking into account the area of ​​\u200b\u200bthe room and the coefficient for the number of walls. For example, one room of 20 m² and one outer wall is taken. In this case, the calculations look like this:

20*100*1.1 = 2200 watts. where 100 is the standard thermal power. If we take the power of one section of the radiator at 170 watts, then the value is 12.94 - that is, you need 13 sections of 170 watts each.

It is important to pay attention to the fact that an overestimation of heat transfer becomes a frequent occurrence, therefore, before buying a heating radiator, it is necessary to study the technical data sheet in order to find out the minimum heat transfer value.

As a rule, there is no need to calculate the area of ​​​​the radiator, the required power or thermal resistance is calculated, and then a suitable model is selected from the assortment offered by sellers. In the event that an accurate calculation is required, then it is more correct to contact specialists, since knowledge of the parameters of the composition of the walls and their thickness, the ratio of the area of ​​\u200b\u200bthe walls, windows and the climatic conditions of the area will be required.

The procedure for calculating heating in the housing stock depends on the availability of metering devices and on how the house is equipped with them. There are several options for completing multi-apartment residential buildings with meters, and according to which, heat energy is calculated:

1. the presence of a common house meter, while apartments and non-residential premises are not equipped with metering devices.
2. heating costs are controlled by a common house device, and all or some rooms are equipped with metering devices.
3. there is no general house device for fixing the consumption and consumption of thermal energy.

Before calculating the number of gigacalories spent, it is necessary to find out the presence or absence of controllers in the house and in each individual room, including non-residential ones. Let's consider all three options for calculating thermal energy, for each of which a specific formula has been developed (posted on the website of state authorized bodies).

Option 1

So, the house is equipped with a control device, and some rooms were left without it. Here it is necessary to take into account two positions: the calculation of Gcal for heating an apartment, the cost of thermal energy for general house needs (ODN).

In this case, formula No. 3 is used, which is based on the readings of the general meter, the area of ​​\u200b\u200bthe house and the footage of the apartment.

Calculation example

We will assume that the controller recorded the house's heating costs at 300 Gcal / month (this information can be obtained from the receipt or by contacting the management company). For example, the total area of ​​the house, which consists of the sum of the areas of all premises (residential and non-residential), is 8000 m² (you can also find this figure from the receipt or from the management company).

Let's take the area of ​​​​an apartment of 70 m² (indicated in the data sheet, rental agreement or registration certificate). The last figure, on which the calculation of payment for consumed heat energy depends, is the tariff established by the authorized bodies of the Russian Federation (indicated on the receipt or found out in the house management company). Today, the heating tariff is 1,400 rubles/gcal.

Substituting the data in formula No. 3, we get the following result: 300 x 70 / 8,000 x 1,400 \u003d 1875 rubles.

Now you can proceed to the second stage of accounting for heating costs spent on the general needs of the house. Two formulas are required here: the search for the volume of services (No. 14) and the payment for the consumption of gigacalories in rubles (No. 10).

In order to correctly determine the volume of heating in this case, it will be necessary to sum up the area of ​​\u200b\u200ball apartments and premises provided for common use (information is provided by the management company).

For example, we have a total footage of 7000 m² (including apartments, offices, retail premises.).

Let's start calculating the payment for the consumption of thermal energy according to formula No. 14: 300 x (1 - 7,000 / 8,000) x 70 / 7,000 \u003d 0.375 Gcal.

Using formula No. 10, we get: 0.375 x 1,400 = 525, where:

• 0.375 - volume of service for heat supply;
• 1400 r. – tariff;
• 525 rubles - amount of payment.

We summarize the results (1875 + 525) and find out that the payment for heat consumption will be 2350 rubles.

Option 2

Now we will calculate payments in those conditions when the house is equipped with a common meter for heating, as well as some apartments are equipped with individual meters. As in the previous case, the calculation will be carried out in two positions (thermal energy consumption for housing and ONE).

We will need formulas No. 1 and No. 2 (accrual rules according to the testimony of the controller or taking into account the norms for heat consumption for residential premises in gcal). Calculations will be carried out in relation to the area of ​​​​a residential building and an apartment from the previous version.

• 1.3 gigacalories - readings of an individual counter;
• 1 1820 r. - approved rate.

• 0.025 gcal - standard indicator of heat consumption per 1 m² of area in an apartment;
• 70 m² - area of ​​the apartment;
• 1 400 rubles - tariff for thermal energy.

As it becomes clear, with this option, the payment amount will depend on the availability of a metering device in your apartment.

Formula No. 13: (300 - 12 - 7,000 x 0.025 - 9 - 30) x 75 / 8,000 \u003d 1.425 gcal, where:

• 300 gcal - indications of a common house meter;
• 12 gcal - the amount of thermal energy used for heating non-residential premises;
• 6,000 m² - the sum of the area of ​​​​all residential premises;
• 0.025 - standard (thermal energy consumption for apartments);
• 9 gcal - the sum of indicators from the meters of all apartments that are equipped with metering devices;
• 35 gcal - the amount of heat spent on the supply of hot water in the absence of its centralized supply;
• 70 m² - area of ​​the apartment;
• 8,000 m² - total area (all residential and non-residential premises in the house).

Please note that this option only includes real amounts of energy consumed, and if your house is equipped with a centralized hot water supply, then the amount of heat spent on hot water needs is not taken into account. The same applies to non-residential premises: if they are not in the house, then they will not be included in the calculation.

• 1.425 gcal - the amount of heat (ONE);

1. 1820 + 1995 = 3,815 rubles - with individual counter.
2. 2 450 + 1995 = 4445 rubles. - without individual device.

Option 3

We are left with the last option, during which we will consider the situation when there is no heat meter on the house. The calculation, as in previous cases, will be carried out in two categories (thermal energy consumption for an apartment and ONE).

We will derive the amount for heating using formulas No. 1 and No. 2 (rules on the procedure for calculating thermal energy, taking into account the readings of individual meters or in accordance with the established standards for residential premises in gcal).

Formula No. 1: 1.3 x 1,400 \u003d 1820 rubles, where:

• 1.3 gcal - readings of an individual meter;
• 1 400 rubles - approved rate.

Formula No. 2: 0.025 x 70 x 1,400 = 2,450 rubles, where:

• 1 400 rubles - approved rate.

As in the second option, the payment will depend on whether your housing is equipped with an individual heat meter. Now it is necessary to find out the amount of heat energy that was spent on general house needs, and this must be done according to formula No. 15 (volume of service for one unit) and No. 10 (amount for heating).

Formula No. 15: 0.025 x 150 x 70 / 7000 \u003d 0.0375 gcal, where:

• 0.025 gcal - standard indicator of heat consumption per 1 m² of living space;
• 100 m² - the sum of the area of ​​\u200b\u200bthe premises intended for general house needs;
• 70 m² - the total area of ​​the apartment;
• 7,000 m² - total area (all residential and non-residential premises).

Formula No. 10: 0.0375 x 1,400 = 52.5 rubles, where:

• 0.0375 - volume of heat (ONE);
• 1400 r. - approved rate.

As a result of the calculations, we found out that the full payment for heating will be:

1. 1820 + 52.5 \u003d 1872.5 rubles. - with individual counter.
2. 2450 + 52.5 \u003d 2,502.5 rubles. – without individual counter.

In the above calculations of payments for heating, data on the footage of the apartment, house, as well as on the meter indicators, which may differ significantly from those that you have, were used. All you need to do is plug your values ​​into the formula and make the final calculation.

Any owner of a city apartment at least once was surprised at the figures on the receipt for heating. It is often not clear on what basis we are charged for heating and why often the residents of a neighboring house pay much less. However, the figures are not taken from nowhere: there is a norm for the consumption of thermal energy for heating, and it is on its basis that the final amounts are formed, taking into account the approved tariffs. How to deal with this complex system?

Where do regulations come from?

The norms for heating residential premises, as well as the norms for the consumption of any utility service, whether it be heating, water supply, etc., are a relatively constant value. They are accepted by the local authorized body with the participation of resource supplying organizations and remain unchanged for three years.

To put it more simply, the company supplying heat to this region submits documents to the local authorities with the rationale for the new standards. During the discussion, they are accepted or rejected at meetings of the city council. After that, the consumed heat is recalculated, and the tariffs for which consumers will pay are approved.

The norms for the consumption of thermal energy for heating are calculated based on the climatic conditions of the region, the type of house, the material of the walls and roof, the deterioration of utility networks and other indicators. The result is the amount of energy that has to be spent on heating 1 square of living space in this building. This is the norm.

The generally accepted unit of measurement is Gcal/sq. m - gigacalorie per square meter. The main parameter is the average ambient temperature during the cold period. Theoretically, this means that if the winter was warm, then you will have to pay less for heating. However, in practice this usually does not work out.

What should be the normal temperature in the apartment?

The standards for heating an apartment are calculated taking into account the fact that a comfortable temperature should be maintained in the living room. Its approximate values ​​are:

• In a living room, the optimum temperature is from 20 to 22 degrees;
• Kitchen - temperature from 19 to 21 degrees;
• Bathroom - from 24 to 26 degrees;
• Toilet - temperature from 19 to 21 degrees;
• Corridor - from 18 to 20 degrees.

If in winter the temperature in your apartment is below the indicated values, it means that your house receives less heat than the norms for heating prescribe. As a rule, in such situations, worn-out city heating systems are to blame, when precious energy is wasted into the air. However, the heating norm in the apartment is not met, and you have the right to complain and demand recalculation.

The most expensive utility service is heating.

Despite the requirement of the legislation on the installation of general house heat consumption meters, for various reasons, a large number of homeowners still pay for heat according to the standards established by local authorities.

I live in just such a house. Those. in our house, a common house meter on the heating system is not installed. Therefore, I decided to calculate how much heat I need to heat my apartment or our MKD and compare my calculation with the consumption standard set for our house (my apartment) in the receipt.

Below I give my calculation, which can be done by each of you. The calculation is not very complicated, but it requires the ability to handle a calculator, knowledge of physics in the volume of eight classes and a little time. Therefore, those of you who are interested in this question, namely, how much heat is needed to heat your apartment, please pick up a calculator and repeat my calculation for your apartment. Then take your utility bill and compare the result of your calculation with the norm according to which you are charged for heating. After that, I will be grateful if you participate in the survey I propose below.

And so the calculation of the required heat consumption:

1. All our houses and apartments are made up of cubic meters of air, which we need to heat up when the temperature outside becomes lower than necessary for a comfortable stay. Thus, it is for heating the air that the heat of the heat supply system consumed by us is spent. How much heat is needed to heat one cubic meter of air by one degree? If you forgot the school physics course, ask the students. They will help you with the calculation. I tried. It works. We take the heat capacity of air - 0.24 Kcal / kg * deg and multiply by the air density - 1.3 kg / m3. We get that to heat 1 m3 of air by one degree, we need 0.312 Kcal/m3*deg or 0.00000031 Gcal/m3*deg.

2. Knowing how much thermal energy I need to heat one cubic meter of air by one degree, I can calculate how much energy I need to heat the whole apartment or even the whole house and not by one, but by any number of degrees. To do this, simply multiply the value obtained above in paragraph 1 by the volume of the room and the number of degrees of heating. It should be noted that in this case we are doing the calculation for the entire heating season, since the standard is set for the entire season and does not depend on the outside air temperature, i.e. assumes a certain average value of heat consumption per month. Of course, in cold months we need more heat for heating, and in warm months we need less. But these fluctuations in heat consumption are averaged over the entire heating period, if the seasonally average outside air temperature is used in the calculation. Therefore, in our calculation, we calculate a certain average value of heat consumption, assuming that we need to heat the air in the room from the average outdoor temperature for the heating season to the required room temperature. We take the required room temperature - plus 20 degrees. In my case, the average outdoor temperature for the heating season is minus 2 degrees. You may have a different average temperature. You can easily find it on the Internet. Therefore, I need to heat the apartment by 22 degrees, from the average outside temperature - minus 2 degrees, to the required room temperature - plus 20 degrees. The area of ​​my apartment is 68.6 m2. Considering the height of the ceiling, taking into account the interfloor ceilings of 3.5 m, I get the heated volume of the apartment - 240 m3. Multiply the volume of an apartment of 240 m3 by 22 degrees of required heating and the required specific energy consumption for heating 1 m3 of air. We get - 0.0016368 Gcal / per apartment * hour. Heating is not an instantaneous process. It takes time. For simplicity and definiteness, we assume that the necessary heating in this case is carried out within an hour.

3. However, the consumption of thermal energy for heating an apartment or house is not only heating indoor air. Heat must be generated somewhere and delivered to a heated room. Naturally, there will be losses. According to the current SNIPs, losses in the heat supply system of a house should average about 13%. Since my house is old, despite the overhaul of the heat supply system of the house in 2012, I take into account the loss for our house of 20% in my calculations. For your first calculation, I also recommend this figure. Then, if necessary, you can refine it. It turns out that in order to heat my apartment, taking into account heat losses in the heat supply system of 20%, I need to consume 0.00196418 Gcal / per apartment * hour from the resource supply organization.

4. However, in addition to losses that inevitably exist in the heat supply system during the generation and transport of heat, there are also so-called household heat emissions in residential premises. This, for example, is the heat released by the switched on electrical appliances, the heat of the air we exhale, the heat released during cooking, etc. Without going into the details of the calculations (these data can be found in publications on the relevant topic), I propose to accept in our case that household heat emissions are 20% of the heat required to heat the room. This is a fairly accurate average estimate. If necessary, you can clarify or check it. Then we get that the required heat consumption of my apartment will be the same 0.0016368 Gcal / per apartment * hour.

5. Since after heating the room, the reverse process immediately begins, i.e. cooling and heating we need all the time during the heating season, in order to compensate for this particular cooling, then in our calculations we need to take into account how much the room cools down through the building envelope (walls, windows, doors, roof, etc.) and the ventilation system for the same unit of time (for definiteness, per hour), for which we heated the room to the temperature we required. Here you should ask yourself the question, can a room that has walls, windows, doors, i.e. cooling barriers, cool down to 100%, i.e. lose all the thermal energy spent on heating, for the same time for which we heated it, well, for example, in an hour. The answer is obvious. No, he can not. Those. cooling (loss of energy spent on heating the room) can only be less than 100% of the energy spent on heating, otherwise why do we need walls, windows, doors, i.e. Walling. In our calculation, for definiteness, we take a cooling of 90%. This means that from the thermal energy spent on heating the apartment through the building envelope every hour I lose 90% of the energy spent on heating, while 10% remains in the room and in the next hour I need 10% less heat to heat. Then it turns out that every hour for heating my apartment during the heating season I need 0.0016368*90%=0.00147312 Gcal/apartment*hour.

6. Accordingly, to calculate the required heat consumption of the apartment per month, it is necessary to multiply the hourly heat consumption of the apartment by the number of hours in the month of the heating season. In my case, the heating season is 220 days or seven full months. Then the average monthly heat consumption of my apartment for heating and ventilation will be 24*220/7*0.00147312=1.111153 Gcal/apartment*month.

7. Now we take the standard of my heat consumption from the receipt. In my case, this is 1.68756 Gcal / month for an apartment. I compare my calculation - 1.111153 Gcal / for an apartment * month and the standard - 1.68756 Gcal / for an apartment * month. The standard exceeds the average heat consumption for the season required by my apartment by 51.87%. Those. paying for heat consumption according to the standard for the entire heating period, I will overpay for the consumption of extra unnecessary to me and charged in excess of the required 52% Gcal of heat. Take your receipts and compare the amount of the standard on the receipt with what you got when calculating. It's very interesting to compare the results.

Creating a heating system in your own home or even in a city apartment is an extremely responsible task. At the same time, it would be completely unreasonable to purchase boiler equipment, as they say, “by eye”, that is, without taking into account all the features of housing. In this, it is quite possible to fall into two extremes: either the power of the boiler will not be enough - the equipment will work “to its fullest”, without pauses, but will not give the expected result, or, conversely, an overly expensive device will be purchased, the capabilities of which will remain completely unclaimed.

But that's not all. It is not enough to purchase the necessary heating boiler correctly - it is very important to optimally select and correctly place heat exchange devices in the premises - radiators, convectors or "warm floors". And again, relying only on your intuition or the "good advice" of your neighbors is not the most reasonable option. In a word, certain calculations are indispensable.

Of course, ideally, such heat engineering calculations should be carried out by appropriate specialists, but this often costs a lot of money. Isn't it interesting to try to do it yourself? This publication will show in detail how heating is calculated by the area of ​​\u200b\u200bthe room, taking into account many important nuances. By analogy, it will be possible to perform, built into this page, will help you perform the necessary calculations. The technique cannot be called completely “sinless”, however, it still allows you to get a result with a completely acceptable degree of accuracy.

The simplest methods of calculation

In order for the heating system to create comfortable living conditions during the cold season, it must cope with two main tasks. These functions are closely related, and their separation is very conditional.

• The first is maintaining an optimal level of air temperature in the entire volume of the heated room. Of course, the temperature level may vary slightly with altitude, but this difference should not be significant. Quite comfortable conditions are considered to be an average of +20 ° C - it is this temperature that, as a rule, is taken as the initial temperature in thermal calculations.

In other words, the heating system must be able to heat a certain volume of air.

If we approach with complete accuracy, then for individual rooms in residential buildings the standards for the necessary microclimate are established - they are defined by GOST 30494-96. An excerpt from this document is in the table below:

• The second is the compensation of heat losses through the structural elements of the building.

The main "enemy" of the heating system is heat loss through building structures.

Alas, heat loss is the most serious "rival" of any heating system. They can be reduced to a certain minimum, but even with the highest quality thermal insulation, it is not yet possible to completely get rid of them. Thermal energy leaks go in all directions - their approximate distribution is shown in the table:

Naturally, in order to cope with such tasks, the heating system must have a certain thermal power, and this potential must not only meet the general needs of the building (apartment), but also be correctly distributed over the premises, in accordance with their area and a number of other important factors.

Usually the calculation is carried out in the direction "from small to large". Simply put, the required amount of thermal energy for each heated room is calculated, the obtained values ​​​​are summed up, approximately 10% of the reserve is added (so that the equipment does not work at the limit of its capabilities) - and the result will show how much power the heating boiler needs. And the values ​​​​for each room will be the starting point for calculating the required number of radiators.

The most simplified and most commonly used method in a non-professional environment is to accept the norm of 100 W of thermal energy per square meter of area:

The most primitive way of counting is the ratio of 100 W / m²

Q = S× 100

Q- the required thermal power for the room;

S– area of ​​the room (m²);

100 — specific power per unit area (W/m²).

For example, room 3.2 × 5.5 m

S= 3.2 × 5.5 = 17.6 m²

Q= 17.6 × 100 = 1760 W ≈ 1.8 kW

The method is obviously very simple, but very imperfect. It is worth mentioning right away that it is conditionally applicable only with a standard ceiling height - approximately 2.7 m (permissible - in the range from 2.5 to 3.0 m). From this point of view, the calculation will be more accurate not from the area, but from the volume of the room.

It is clear that in this case the value of specific power is calculated per cubic meter. It is taken equal to 41 W / m³ for a reinforced concrete panel house, or 34 W / m³ - in brick or made of other materials.

Q = S × h× 41 (or 34)

h- ceiling height (m);

41 or 34 - specific power per unit volume (W / m³).

For example, the same room, in a panel house, with a ceiling height of 3.2 m:

Q= 17.6 × 3.2 × 41 = 2309 W ≈ 2.3 kW

The result is more accurate, since it already takes into account not only all the linear dimensions of the room, but even, to a certain extent, the features of the walls.

But still, it is still far from real accuracy - many nuances are “outside the brackets”. How to perform calculations closer to real conditions - in the next section of the publication.

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Carrying out calculations of the required thermal power, taking into account the characteristics of the premises

The calculation algorithms discussed above are useful for the initial “estimate”, but you should still rely on them completely with very great care. Even to a person who does not understand anything in building heat engineering, the indicated average values ​​\u200b\u200bmay seem doubtful - they cannot be equal, say, for the Krasnodar Territory and for the Arkhangelsk Region. In addition, the room - the room is different: one is located on the corner of the house, that is, it has two external walls, and the other is protected from heat loss by other rooms on three sides. In addition, the room may have one or more windows, both small and very large, sometimes even panoramic. And the windows themselves may differ in the material of manufacture and other design features. And this is not a complete list - just such features are visible even to the "naked eye".

In a word, there are a lot of nuances that affect the heat loss of each particular room, and it is better not to be too lazy, but to carry out a more thorough calculation. Believe me, according to the method proposed in the article, this will not be so difficult to do.

General principles and calculation formula

The calculations will be based on the same ratio: 100 W per 1 square meter. But that's just the formula itself "overgrown" with a considerable number of various correction factors.

Q = (S × 100) × a × b × c × d × e × f × g × h × i × j × k × l × m

The Latin letters denoting the coefficients are taken quite arbitrarily, in alphabetical order, and are not related to any standard quantities accepted in physics. The meaning of each coefficient will be discussed separately.

• "a" - a coefficient that takes into account the number of external walls in a particular room.

Obviously, the more external walls in the room, the larger the area through which heat loss occurs. In addition, the presence of two or more external walls also means corners - extremely vulnerable places in terms of the formation of "cold bridges". The coefficient "a" will correct for this specific feature of the room.

The coefficient is taken equal to:

- external walls No(indoor): a = 0.8;

- outer wall one: a = 1.0;

- external walls two: a = 1.2;

- external walls three: a = 1.4.

• "b" - coefficient taking into account the location of the external walls of the room relative to the cardinal points.

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Even on the coldest winter days, solar energy still has an effect on the temperature balance in a building. It is quite natural that the side of the house that is facing south receives some heating from the sun's rays, and heat loss through it is lower.

But the walls and windows facing north never “see” the Sun. The eastern part of the house, although it "grabs" the morning sun's rays, still does not receive any effective heating from them.

Based on this, we introduce the coefficient "b":

- the outer walls of the room look at North or East: b = 1.1;

- the outer walls of the room are oriented towards South or West: b = 1.0.

• "c" - coefficient taking into account the location of the room relative to the winter "wind rose"

Perhaps this amendment is not so necessary for houses located in areas protected from the winds. But sometimes the prevailing winter winds can make their own "hard adjustments" to the thermal balance of the building. Naturally, the windward side, that is, "substituted" to the wind, will lose much more body, compared to the leeward, opposite side.

Based on the results of long-term meteorological observations in any region, the so-called "wind rose" is compiled - a graphic diagram showing the prevailing wind directions in winter and summer. This information can be obtained from the local hydrometeorological service. However, many residents themselves, without meteorologists, know perfectly well where the winds mainly blow from in winter, and from which side of the house the deepest snowdrifts usually sweep.

If there is a desire to carry out calculations with higher accuracy, then the correction factor “c” can also be included in the formula, taking it equal to:

- windward side of the house: c = 1.2;

- leeward walls of the house: c = 1.0;

- wall located parallel to the direction of the wind: c = 1.1.

• "d" - a correction factor that takes into account the peculiarities of the climatic conditions of the region where the house was built

Naturally, the amount of heat loss through all building structures of the building will greatly depend on the level of winter temperatures. It is quite clear that during the winter the thermometer indicators “dance” in a certain range, but for each region there is an average indicator of the lowest temperatures characteristic of the coldest five-day period of the year (usually this is characteristic of January). For example, below is a map-scheme of the territory of Russia, on which approximate values ​​​​are shown in colors.

Usually this value is easy to check with the regional meteorological service, but you can, in principle, rely on your own observations.

So, the coefficient "d", taking into account the peculiarities of the climate of the region, for our calculations in we take equal to:

— from – 35 °С and below: d=1.5;

— from – 30 °С to – 34 °С: d=1.3;

— from – 25 °С to – 29 °С: d=1.2;

— from – 20 °С to – 24 °С: d=1.1;

— from – 15 °С to – 19 °С: d=1.0;

— from – 10 °С to – 14 °С: d=0.9;

- not colder - 10 ° С: d=0.7.

• "e" - coefficient taking into account the degree of insulation of external walls.

The total value of the heat loss of the building is directly related to the degree of insulation of all building structures. One of the "leaders" in terms of heat loss are walls. Therefore, the value of the thermal power required to maintain comfortable living conditions in the room depends on the quality of their thermal insulation.

The value of the coefficient for our calculations can be taken as follows:

- external walls are not insulated: e = 1.27;

- medium degree of insulation - walls in two bricks or their surface thermal insulation with other heaters is provided: e = 1.0;

– insulation was carried out qualitatively, on the basis of heat engineering calculations: e = 0.85.

Later in the course of this publication, recommendations will be given on how to determine the degree of insulation of walls and other building structures.

• coefficient "f" - correction for ceiling height

Ceilings, especially in private homes, can have different heights. Therefore, the thermal power for heating one or another room of the same area will also differ in this parameter.

It will not be a big mistake to accept the following values ​​​​of the correction factor "f":

– ceiling height up to 2.7 m: f = 1.0;

— flow height from 2.8 to 3.0 m: f = 1.05;

– ceiling height from 3.1 to 3.5 m: f = 1.1;

– ceiling height from 3.6 to 4.0 m: f = 1.15;

– ceiling height over 4.1 m: f = 1.2.

• « g "- coefficient taking into account the type of floor or room located under the ceiling.

As shown above, the floor is one of the significant sources of heat loss. So, it is necessary to make some adjustments in the calculation of this feature of a particular room. The correction factor "g" can be taken equal to:

- cold floor on the ground or over an unheated room (for example, basement or basement): g= 1,4 ;

- insulated floor on the ground or over an unheated room: g= 1,2 ;

- a heated room is located below: g= 1,0 .

• « h "- coefficient taking into account the type of room located above.

The air heated by the heating system always rises, and if the ceiling in the room is cold, then increased heat losses are inevitable, which will require an increase in the required heat output. We introduce the coefficient "h", which takes into account this feature of the calculated room:

- a "cold" attic is located on top: h = 1,0 ;

- an insulated attic or other insulated room is located on top: h = 0,9 ;

- any heated room is located above: h = 0,8 .

• « i "- coefficient taking into account the design features of windows

Windows are one of the "main routes" of heat leaks. Naturally, much in this matter depends on the quality of the window structure itself. Old wooden frames, which were previously installed everywhere in all houses, are significantly inferior to modern multi-chamber systems with double-glazed windows in terms of their thermal insulation.

Without words, it is clear that the thermal insulation qualities of these windows are significantly different.

But even between PVC-windows there is no complete uniformity. For example, a two-chamber double-glazed window (with three glasses) will be much warmer than a single-chamber one.

This means that it is necessary to enter a certain coefficient "i", taking into account the type of windows installed in the room:

- standard wooden windows with conventional double glazing: i = 1,27 ;

– modern window systems with single-chamber double-glazed windows: i = 1,0 ;

– modern window systems with two-chamber or three-chamber double-glazed windows, including those with argon filling: i = 0,85 .

• « j" - correction factor for the total glazing area of ​​the room

No matter how high-quality the windows are, it will still not be possible to completely avoid heat loss through them. But it is quite clear that it is impossible to compare a small window with panoramic glazing almost on the entire wall.

First you need to find the ratio of the areas of all the windows in the room and the room itself:

x = ∑SOK /SP

∑ SOK- the total area of ​​windows in the room;

SP- area of ​​the room.

Depending on the value obtained and the correction factor "j" is determined:

- x \u003d 0 ÷ 0.1 →j = 0,8 ;

- x \u003d 0.11 ÷ 0.2 →j = 0,9 ;

- x \u003d 0.21 ÷ 0.3 →j = 1,0 ;

- x \u003d 0.31 ÷ 0.4 →j = 1,1 ;

- x \u003d 0.41 ÷ 0.5 →j = 1,2 ;

• « k" - coefficient that corrects for the presence of an entrance door

The door to the street or to an unheated balcony is always an additional "loophole" for the cold

The door to the street or to an open balcony is able to make its own adjustments to the heat balance of the room - each opening of it is accompanied by the penetration of a considerable amount of cold air into the room. Therefore, it makes sense to take into account its presence - for this we introduce the coefficient "k", which we take equal to:

- no door k = 1,0 ;

- one door to the street or balcony: k = 1,3 ;

- two doors to the street or to the balcony: k = 1,7 .

• « l "- possible amendments to the connection diagram of heating radiators

Perhaps this will seem like an insignificant trifle to some, but still - why not immediately take into account the planned scheme for connecting heating radiators. The fact is that their heat transfer, and hence their participation in maintaining a certain temperature balance in the room, changes quite noticeably with different types of insertion of supply and return pipes.

Illustration	Radiator insert type	The value of the coefficient "l"
	Diagonal connection: supply from above, "return" from below	l = 1.0
	Connection on one side: supply from above, "return" from below	l = 1.03
	Two-way connection: both supply and return from the bottom	l = 1.13
	Diagonal connection: supply from below, "return" from above	l = 1.25
	Connection on one side: supply from below, "return" from above	l = 1.28
	One-way connection, both supply and return from below	l = 1.28

• « m "- correction factor for the features of the installation site of heating radiators

And finally, the last coefficient, which is also associated with the features of connecting heating radiators. It is probably clear that if the battery is installed openly, is not obstructed by anything from above and from the front part, then it will give maximum heat transfer. However, such an installation is far from always possible - more often, radiators are partially hidden by window sills. Other options are also possible. In addition, some owners, trying to fit heating priors into the created interior ensemble, hide them completely or partially with decorative screens - this also significantly affects the heat output.

If there are certain “baskets” on how and where the radiators will be mounted, this can also be taken into account when making calculations by entering a special coefficient “m”:

So, there is clarity with the calculation formula. Surely, some of the readers will immediately take up their heads - they say, it's too complicated and cumbersome. However, if the matter is approached systematically, in an orderly manner, then there is no difficulty at all.

Any good homeowner must have a detailed graphical plan of their "possessions" with affixed dimensions, and usually oriented to the cardinal points. It is not difficult to specify the climatic features of the region. It remains only to walk through all the rooms with a tape measure, to clarify some of the nuances for each room. Features of housing - "vertical neighborhood" from above and below, the location of the entrance doors, the proposed or existing scheme for installing heating radiators - no one except the owners knows better.

It is recommended to immediately draw up a worksheet, where you enter all the necessary data for each room. The result of the calculations will also be entered into it. Well, the calculations themselves will help to carry out the built-in calculator, in which all the coefficients and ratios mentioned above are already “laid”.

If some data could not be obtained, then, of course, they can not be taken into account, but in this case, the “default” calculator will calculate the result, taking into account the least favorable conditions.

It can be seen with an example. We have a house plan (taken completely arbitrary).

The region with the level of minimum temperatures in the range of -20 ÷ 25 °С. Predominance of winter winds = northeasterly. The house is one-story, with an insulated attic. Insulated floors on the ground. The optimal diagonal connection of radiators, which will be installed under the window sills, has been selected.

Let's create a table like this:

Then, using the calculator below, we make a calculation for each room (already taking into account a 10% reserve). With the recommended app, it won't take long. After that, it remains to sum the obtained values ​​\u200b\u200bfor each room - this will be the required total power of the heating system.