How to calculate the heating system for the house. Individual calculation of the heating system of a private house

The problem of providing heat does not arise only among residents of areas with "eternal summer". In our conditions, such a problem needs to be solved. The quality and efficiency of the installed system in the future depends on how accurately and competently the calculation of heating will be performed.

At the stage of circuit design, all possible options are considered and the optimal one is selected. Calculation methods are different and they are carried out taking into account the features of the selected system type.

What heating system is preferable?

In each case, there are reasons for choosing one or another type, and they all have the right to exist.

There are many advantages in space heating from electric heaters, underfloor heating, infrared radiation - environmental friendliness, noiselessness and combinatoriality with other schemes. But this type is considered to be highly costly in terms of energy source, therefore, in heating calculations, it is usually considered as an additional option.

Air heating is a rarity. Heating by means of stoves and fireplaces is reasonable in places where there are no problems with the supply of firewood or other heat carrier. Both of these types are also meant only as auxiliary to the main scheme.

The radiator-type water heating system is currently considered the most common, and it should be discussed thoroughly.

Stages of heating design

Regardless of the purpose of the object - a private house, office or a large manufacturing enterprise, a detailed project is required. A complete calculation of the heating system includes energy consumption calculations based on the area of ​​​​all rooms and their location on the site, the choice of fuel type with its storage location, boiler and other equipment.

Preparatory

It is best if the designers have construction drawings - this will speed up the work and ensure the accuracy of the data. At this stage, the energy needs are calculated (power and type of boiler, radiators), possible heat losses are determined. The optimal heat distribution scheme, system equipment, level of automation and control are selected.

First stage

A preliminary design is submitted to the customer for approval, which reflects the methods of communication wiring and placement of heating equipment. On its basis, an estimate is formed, modeling, hydraulic calculation of the heating system is carried out, and work begins on the creation of working drawings.

Development of a complete package of documents

The designer completes and draws up the project in accordance with the requirements of SNiP, which later makes it easy to coordinate the documentation with the relevant authorities. The project includes:

• initial data and sketches;
• costings;
• main drawings - floor plans and boiler room, axonometric diagrams, sections with detailing of nodes;
• an explanatory note with the rationale for the decisions made and calculated indicators in conjunction with other engineering systems, technical and operational characteristics of the facility, information on security measures;
• specification of equipment and materials.

The finished project is considered the key to the efficiency and practicality of heating, its trouble-free operation.

General principles and features of heating calculation

The type of system directly depends on the dimensions of the heated object, therefore, the calculation of heating by area is necessary. In buildings over 100 sq.m. a forced circulation scheme is arranged, because in this case a system with natural movement of heat flows is not appropriate due to its inertia.

As part of such a scheme, circulation pumps are provided. In this case, one important nuance must be taken into account: pumping equipment must be connected to the return line (from appliances to the boiler) to prevent contact of parts of the units with hot water.

The calculation work is based on the features of each applied scheme.

• In a two-pipe system, the numbering of the calculated zones starts from the heat generator (or ITP) with the designation of the points of all nodes on the supply line, risers and branches of the sections. Areas of a fixed diameter with a constant coolant flow rate are taken into account, based on the heat balance of the room.
• A single-pipe wiring diagram implies a similar approach with the determination of the sections of pipelines and risers by pressure.
• In the vertical system version, the designation of the numbers of risers (instrument branches) is done clockwise from the place at the top left point of the house.

The calculation of the hydraulics for heating a private house is one of the complex elements of designing a water system. It is on its basis that the balance of heat in the premises is determined, a decision is made on the system configuration, the type of heating batteries, pipes and valves is selected.

Heating boiler calculation

There is a simplified method that is used for a water system with standard components and a single-circuit boiler. The required generator power for a cottage is determined by multiplying the total volume of the house by the required amount of thermal energy per 1 mᵌ (for the European part of Russia, this figure is 40 W).

The specific power of the boiler, depending on the climatic zone, is generally accepted and is: for the Southern regions - less than 1.0 kW, in the Central - up to 1.5 kW, the Northern - up to 2.0 kW.

Heating radiators

The construction market now presents 3 of their constructive types: tubular, sectional and panel radiators. According to the material they are divided:

• on obsolete cast iron;
• lightweight aluminum with the fastest heating;
• steel - the most popular;
• bimetallic, designed to work under high pressure.

How is the calculation of heating radiators applied to the water system?

Method 1

Here the calculation principle is involved, based on the area of ​​\u200b\u200ba specific room and the power of one section. There is a certain guideline: the power of 100 watts of one radiator for fast and sufficient heating of 1 mᵌ of the room. This indicator is established by building codes and is used in formulas.

The selection of heating devices using this method is carried out by simple mathematical operations: multiplying the area of ​​\u200b\u200bthe room by 100, followed by dividing by the power of one section of the battery. The last characteristic is taken from the technical data of a particular radiator.

As a result, it is easy to determine the number of sections of the device and the required number of batteries for the room. When calculating, windows should be taken into account, adding another 10% to the number of sections for each window opening.

Method 2

Based on an average height of 2.5 m for a typical living space and heating 1.8 m² of its area with one section. As a result of simply dividing the total area by the last indicator, a radiator with the required number of sections is obtained (with the fractional number rounded up).

Method 3

This is a kind of standard method for calculating heating radiators, based on averages and room volume. Namely: 1 section with a power of 200 W is required for conditional heating of 5 m² of room volume.

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A modern alternative to sectional batteries is panel radiators. To calculate their number, a method without clear data is used. Its essence is as follows: the accepted indicator of 40 W for heating 1 mᵌ of a room is multiplied by its area and height. The received power serves as a criterion for determining the number of batteries, based on the power characteristics of a particular model.

What to pay attention to

When designing systems, many important factors, both general and individual, are taken into account. Everything matters here: the climatic conditions of the location of the object, the temperature regime in the heating season, the materials of the walls and roof.

If additional thermal insulation is made in the room or warm window structures are installed in it, then this definitely reduces heat loss. Therefore, the calculation of space heating in this case is carried out with other coefficients. And vice versa: each external wall or a wide protruding window sill above the radiator can significantly change the calculated picture.

It is considered wrong to choose a battery based on the size of the window. If in doubt - to install one long device, or two small ones, then it is better to stop at the latter option. They will heat up faster and are considered a more economical solution.

If the devices are planned to be covered with panels (with slots or gratings), then 15% is added to the required power. The heat dissipation of the battery is little affected by its width and height, although the larger the metal surface, the better. But for the final conclusions, you still need to familiarize yourself with the technical characteristics of the model.

Convenient form - heating calculation calculator

All the above methods are not always subject to the ordinary consumer, as they require certain skills and knowledge, the ability to operate with all the initial and received data. A convenient calculator for calculating heating in the "online" mode is an opportunity to carry out all the calculation manipulations in just seconds.

In order to use it, engineering and technical training is not required. You need to enter several parameters for the object into the program, after which the functionality will give the necessary indicators with the cost of installation work.

Use our simple heating system calculator at the bottom of this page.

Finally

There are no particular difficulties in calculating heating systems - there are only nuances and features that have already been described. But the work must be done carefully, with skill and proper use of available information. Do not neglect the recommendations and help of specialists.

In the process of building any house, sooner or later the question arises - how to calculate the heating system correctly? This actual problem will never exhaust its resource, because if you buy a boiler of less power than necessary, you will have to spend a lot of effort to create secondary heating with oil and infrared radiators, heat guns, and electric fireplaces.

In addition, monthly maintenance, due to expensive electricity, will cost you a pretty penny. The same thing will happen if you buy a high-power boiler that will work at half strength, and consume no less fuel.

Our calculator for calculating the heating of a private house will help you avoid the typical mistakes of novice builders. You will receive as close to reality the value of heat losses and the required heat output of the boiler according to the current data of SNiPs and SPs (sets of rules).

The main advantage of the calculator on the site is the reliability of the calculated data and the absence of manual calculations, the whole process is automated, the initial parameters are maximally generalized, you can easily see their values ​​\u200b\u200bin your home plan or fill in based on your own experience.

Calculation of a boiler for heating a private house

With the help of our calculator for calculating heating for a private house, you can easily find out the required boiler power to heat your cozy "nest".

As you remember, in order to calculate the heat loss rate, you need to know several values ​​\u200b\u200bof the main components of the house, which together account for more than 90% of the total losses. For your convenience, we have added to the calculator only those fields that you can fill out. without special knowledge:

• glazing;
• thermal insulation;
• the ratio of the area of ​​​​windows and floor;
• outside temperature;
• the number of walls facing the outside;
• which room is above the calculated one;
• room height;
• room area.

After you get the value of the heat loss of the house, a correction factor of 1.2 is taken to calculate the required boiler power.

How to work on the calculator

Remember that the thicker the glazing and the better the thermal insulation, the less heating power will be required.

To get results, you need to answer the following questions:

1. Choose one of the proposed types of glazing (triple or double glazing, conventional double glazing).
2. How are your walls insulated? Solid thick insulation from a couple of layers of mineral wool, polystyrene foam, EPPS for the north and Siberia. Maybe you live in Central Russia and one layer of insulation is enough for you. Or are you one of those who builds a house in the southern regions and a double hollow brick is suitable for him.
3. What is your window-to-floor area ratio, in %. If you do not know this value, then it is calculated very simply: divide the floor area by the window area and multiply by 100%.
4. Enter the minimum winter temperature for a couple of seasons and round up. Do not use the average temperature for winters, otherwise you risk getting a smaller boiler and the house will not be heated enough.
5. Do we calculate for the whole house or just for one wall?
6. What is above our room. If you have a one-story house, select the type of attic (cold or warm), if the second floor, then a heated room.
7. The height of the ceilings and the area of ​​​​the room are necessary to calculate the volume of the apartment, which in turn is the basis for all calculations.

Calculation example:

• one-story house in the Kaliningrad region;
• wall length 15 and 10 m, insulated with one layer of mineral wool;
• ceiling height 3 m;
• 6 windows of 5 m2 from a double-glazed window;
• the minimum temperature for the last 10 years is 26 degrees;
• we calculate for all 4 walls;
• from above a warm heated attic;

The area of ​​our house is 150 m2, and the area of ​​windows is 30 m2. 30/150*100=20% window to floor ratio.

We know everything else, we select the appropriate fields in the calculator and we get that our house will lose 26.79 kW of heat.

26.79 * 1.2 \u003d 32.15 kW - the required heating capacity of the boiler.

DIY heating system

It is impossible to calculate the heating circuit of a private house without assessing the heat loss of the surrounding structures.

In Russia, as a rule, long cold winters, buildings lose heat due to temperature differences inside and outside the premises. The larger the area of ​​\u200b\u200bthe house, enclosing and through structures (roof, windows, doors), the greater the value of heat loss comes out. The material and thickness of the walls, the presence or absence of thermal insulation have a significant impact.

For example, walls made of wood and aerated concrete have a much lower thermal conductivity than brick. Materials with maximum thermal resistance are used as insulation (mineral wool, expanded polystyrene).

Before creating a heating system at home, you need to carefully consider all the organizational and technical aspects, so that immediately after the construction of the “box”, you can proceed to the final phase of construction, and not postpone the long-awaited settlement for many months.

Heating in a private house is based on the "three elephants":

• heating element (boiler);
• pipe system;
• radiators.

Which boiler is better to choose for a house?

Heating boilers are the main component of the entire system. It is they who will provide heat to your home, so their choice should be treated with particular care. According to the type of food they are divided into:

• electrical;
• solid fuel;
• liquid fuel;
• gas.

Each of them has a number of significant advantages and disadvantages.

1. Electric boilersdid not gain great popularity, primarily because of the rather high cost and high cost of maintenance. Electricity tariffs leave much to be desired, there is a possibility of a power line break, as a result of which your home may be left without heating.
2. Solid fuelboilersoften used in remote villages and towns where there are no centralized communication networks. They heat water with firewood, briquettes and coal. An important disadvantage is the need for constant monitoring of fuel, if the fuel burns out and you do not have time to replenish supplies, the house will stop heating. In modern models, this problem is solved due to the automatic feeder, but the price of such devices is incredibly high.
3. Oil boilers, in the vast majority of cases, run on diesel fuel. They have excellent performance due to the high efficiency of the fuel, but the high cost of raw materials and the need for diesel tanks limit many buyers.
4. The best solution for a country house are gas boilers. Due to their small size, low gas prices and high heat output, they have won the trust of most of the population.

How to choose pipes for heating?

Heating mains supply all heating devices in the house. Depending on the material of manufacture, they are divided into:

• metal;
• metal-plastic;
• plastic.

Metal pipes the most difficult to install (due to the need for welding seams), are susceptible to corrosion, are heavy and expensive. The advantages are high strength, resistance to temperature extremes and the ability to withstand high pressures. They are used in apartment buildings, in private construction it is not advisable to use them.

Polymer pipes from metal-plastic and polypropylene are very similar in their parameters. The lightness of the material, plasticity, no corrosion, noise suppression and, of course, low price. The only difference between the former is the presence of an aluminum layer between two layers of plastic, due to which the thermal conductivity increases. Therefore, metal-plastic pipes are used for heating, and plastic pipes for water supply.

Choosing radiators for the home

The last element of a classic heating system is radiators. They are also divided according to the material into the following groups:

• cast iron;
• steel;
• aluminum.

Cast iron batteries are familiar to everyone since childhood, because they were installed in almost all apartment buildings. They have high heat capacity (cool down for a long time), resistant to temperature and pressure drops in the system. The downside is the high price, fragility and complexity of installation.

They were replaced steel radiators. A wide variety of shapes and sizes, low cost and ease of installation have influenced the ubiquitous distribution. However, they also have their drawbacks. Due to the low heat capacity, the batteries cool down quickly, and the thin case does not allow them to be used in networks with high pressure.

Recently, heaters from aluminum. Their main advantage is high heat transfer, this allows you to warm up the room to an acceptable temperature in 10-15 minutes. However, they are demanding on the coolant, if alkalis or acids are contained in large quantities inside the system, then the life of the radiator is significantly reduced.

Use the proposed tools for calculating the heating of a private house and design a heating system that will heat your home efficiently, reliably and for a long time, even in the harshest winters.

The presence of an efficient heating system is the main condition for creating a comfortable atmosphere in the home. When calculating it, many factors are taken into account: the type of floors, the quality of thermal insulation, the location of window openings, the climatic features of the region, etc. Engineering calculations look very cumbersome and are not clear to the average consumer. To facilitate the arrangement of heating, a simplified calculation was created, with which you can independently make the necessary calculations.

How to calculate the heating system for a private house?

Since the home heating system consists of several elements, each of which must cope with its tasks by 100%, the calculations will concern all components separately. Of course, a simplified calculation will not give maximum accuracy, but the errors will not be catastrophic.

For the arrangement of heating, we need to know:

• power of the heat generator - boiler;
• number of radiators (batteries);
• circulation pump performance.

Only by correctly determining these indicators, we will be able to achieve effective heating of a private house, ensuring a comfortable temperature in the home even in the most severe frost. Let's consider each stage of calculations separately!

How to calculate a boiler for heating a private house?

Heat generators have various operating parameters, the main of which is the thermal characteristic - power. It is on it that they first of all pay attention when choosing equipment. Some believe that the main thing is to purchase a device with a performance that is not less than the required parameter. However, the use of overly powerful units will lead to an increase in heating costs, rapid wear of equipment, the appearance of condensate on the walls of the chimney and other unpleasant consequences.

Ideally, you need to correctly perform the calculations and add 20% to the resulting value. They will serve as a backup in case of unforeseen circumstances, such as a strong drop in outdoor air temperature or a decrease in the supply of fuel used. The calculations will be the same for all types of heat generators, the main thing is to take into account the features of the room.

How to calculate a gas boiler for heating a private house?

If the ceilings in a dwelling do not exceed 3 meters, and the house itself is built according to a standard design, then calculating the power of a heat generator will not be very difficult. But in order to carry out calculations, we need to know the specific power of the unit per 10 m² of area, depending on the region of location:

• warm southern regions - 0.7-0.9 kW;
• the middle lane with a temperate continental climate - 1.0-1.2 kW;
• Moscow region - 1.2-1.5 kW;
• north - 1.5-2.0 kW.

Suppose we need to select a heating boiler for a private house with an area of ​​250 m², which is located in the northern region. The formula will help us to perform the calculations:

M=P*MUD/10, where

M - boiler power;

P is the area of ​​the heated dwelling;

MUD - specific power of the boiler, which in our case is 2 kW.

Substituting the numerical values, we get: 250*2/10=50 kW. Therefore, the power of our heat generator must be at least 50 kW. If it is planned to install a two-circuit unit that will not only heat the room, but also heat water for domestic needs, another 25% must be added to the figure obtained.

How to calculate an electric boiler for heating a private house?

As we have already mentioned, power calculation is relevant for all types of heat generators. However, there is an opinion that only small areas can be heated with electric boilers. This is not so, because the modern market offers models powered by electricity that can heat up to 1000 m². The question is, is it beneficial to use them?

Often, electric boilers in large houses and cottages act as an additional source of heat, which is associated with the high cost of electricity and frequent problems with its supply. It is safe to say that this type of equipment is best used for heating small dwellings, otherwise the amount of utilities will be impressive. It is advisable to choose multi-stage models, the power of which starts from 6 kW, since with their help you can significantly reduce electricity consumption.

How to calculate heating radiators for a private house?

We figured out the intricacies of choosing boilers, now we can proceed to the next step - calculating the number of heating batteries. This parameter is calculated for each room separately. Let's say we need to calculate how many radiator sections we need to heat a 35 m² room. For installation, cast-iron heaters with a power of one section of 190 W were chosen, which is indicated in the passport.

• first stage of calculations: 35*100= 3500W, where 100 W is the standard power required to heat 1 m²;
• second stage of calculations: 3500/190=18 sections.

Therefore, the heating system of our calculation room should include 18 radiator sections. However, these calculations cannot be called accurate, because there are heat losses, which must be foreseen at the stage of calculations. For this, correction factors are used. The easiest way to multiply the resulting value is 1.1 if:

• ceilings in the house above 3 meters;
• some walls in the room are external;
• there is more than one window in the room;
• home insulation leaves much to be desired.

Coefficients 1.1 are entered into the formula in the presence of each of the above conditions.

How to calculate heating batteries for a private house with coefficients?

Let's assume that the height of our calculation room is 3.3 meters, there are two windows and one outer wall:

• first stage of calculations: 35*100*1.1*1.1*1.1=4658.5W;
• second stage of calculations: 4658,5/190=25 sections.

Adjusted calculations show that we need 25 radiator sections to heat 35 m². Since there are 2 windows in the room, the number of ribs must be divided between them in order to reduce the loss of thermal energy.

How to calculate a pump for heating a private house?

As a rule, a circulation pump is introduced into the home heating system, which accelerates the movement of the coolant through the pipes and increases the heating efficiency. To determine the required performance of this additional equipment, it is necessary to know the value of the upper point of the system, the area of ​​\u200b\u200bthe room and the resistance of the heating network.

The easiest way to find out the resistance is by the type of radiators used:

• cast iron - 1 m;
• aluminum - 1.2 m;
• bimetallic - 2 m.

In our example, the area of ​​\u200b\u200bthe house is 250 m², the height from the pump to the upper heater is 6 meters, our batteries are cast iron. We carry out calculations:

• pump head: 6+1=7 meters;
• amount of electricity consumed: 250/10=25 kW, because according to the standard, the required heat per 10 m² \u003d 1 kW. We translate into other units of measurement: 25*0.86=24.08 kcal.
• pump performance: 24.08/10=2.41 m³/h, where 10 is the recommended temperature difference in the heating system.

According to calculations, to heat our house of 250 m², a circulation pump with a capacity of 2.41 m³ / h at a head of 7 meters is required. Ideally, the equipment should be three-speed, and the indicators we need should be the characteristics of the second speed.

Knowing how to correctly calculate the heating in a private house, you can easily calculate the optimal performance of each element of the system. Of course, the calculation of specialists will be more accurate, but if you do the work yourself, the above formulas will allow you to achieve minimal errors. Remember that the level of comfort in the home will completely depend on the correctness of the calculations!

To date, the most well-known heating system for a private house is independent heating using a water-heating boiler. Oil stoves, electric fireplaces, fan heaters and infrared heaters are commonly used as supplemental space heating.

The heating system of a private house is based on elements such as heating devices (radiators, batteries), a main pipe and a shut-off and control device. All elements of the system are necessary to provide the premises of a private house with thermal energy, which enters the heating devices from a heat generator. The service life and performance of a heating system based on a water heating boiler directly depend on high-quality installation and careful use. But there is a factor that plays an equally important role - the skillful calculation of the heating system.

Calculation of heating of a country house

Consider one of the simplest formulas for calculating the water heating system for heating a private house. For ease of understanding, standard room types will be taken into account. The calculations in the example are based on a single-circuit heating boiler, since it is the most common type of heat generator in the heating system of a suburban area.

As an example, a two-story house is taken, on the second floor of which there are 3 bedrooms and 1 toilet. On the ground floor there is a living room, a corridor, a second toilet, a kitchen and a bathroom. To calculate the volume of rooms, the following formula is used: the area of ​​\u200b\u200bthe room multiplied by its height equals the volume of the room. The calculation calculator looks like this:

• bedroom No. 1: 8 m 2 × 2.5 m = 20 m 3;
• bedroom number 2: 12 m 2 × 2.5 m = 30 m 3;
• bedroom number 3: 15 m 2 × 2.5 m = 37.5 m 3;
• toilet No. 1: 4 m 2 × 2.5 m = 10 m 3;
• living room: 20 m 2 × 3 m = 60 m 3;
• corridor: 6 m 2 × 3 m = 18 m 3;
• toilet No. 2: 4 m 2 × 3 m \u003d 12 m 3;
• kitchen: 12 m 2 × 3 m = 36 m 3;
• bathroom: 6 m 2 × 3 m = 18 m 3.

After calculating the volume of all rooms, it is necessary to summarize the results obtained. As a result, the total volume of the house was 241.5 m 3 (rounded up to 242 m 3). The calculations necessarily take into account rooms in which there may not be heating devices (corridor). As a rule, the thermal energy in the house goes outside the premises and passively heats areas where heating devices are not installed.

Basic elements of heating systems. Click on the photo to enlarge.

The next step is to calculate the power of the water heating boiler, which is based on the required amount of heat energy per m 3. In each climatic zone, the indicator varies, with a focus on the minimum outdoor temperature in winter. For calculation, an arbitrary indicator of the proposed region of the country is taken, which is 50 W / m 3. The calculation formula is as follows: 50 W × 242 m 3 \u003d 12100 W.

To simplify the calculations, there are special programs. Click on the photo to enlarge.

The resulting indicator will need to be raised to a coefficient equal to 1.2. This will allow adding 20% ​​of the reserve power to the boiler, which will ensure its operation in the savings mode without any special overloads. As a result, we got the boiler power, which is equal to 14.6 kW. A water heating system with such power is quite easy to find, since a standard single-circuit boiler has a power of 10-15 kW.

Calculation of heating devices

Calculations are based on standard aluminum batteries. Each section of the battery produces 150 W of thermal energy at a water temperature of 70°C.

Having calculated the required heat energy for a separate room, you need to divide it by 150. The radiator heating calculator looks like this:

• bedroom No. 1: 20 m 3 × 50 W × 1.2 = 1200 W (radiator with 8 sections);
• bedroom No. 2: 30 m 3 × 50 W × 1.2 = 1800 W (radiator with 12 sections);
• bedroom No. 3: 37.5 m 3 × 50 W × 1.2 = 2250 W (radiator with 15 sections);
• toilet No. 1: 10 m 3 × 50 W × 1.2 = 600 W (radiator with 4 sections);
• living room: 60 m 3 × 50 W × 1.2 = 3600 W (radiator with 24 sections);
• corridor: 18 m 3 × 50 W × 1.2 = 1080 W (rounded up to 1200 W, an 8-section radiator is required);
• WC 2: 12 m 3 × 50 W × 1.2 = 720 W (rounded up to 750 W, 5-section radiator required);
• kitchen: 36 m 3 × 50 W × 1.2 = 2160 W (rounded up to 2250 W, a radiator with 15 sections is required);
• bathroom: 18 m 3 × 55 W × 1.2 = 1188 W (rounded up to 1200 W, an 8-section radiator is required).

The bathroom needs to be heated better, so the average is increased to 55 watts.

The formula for calculating sections of the heating battery. Click on the photo to enlarge.

In large rooms, it is necessary to install several radiators with the total number of required sections. For example, in bedroom number 2, you can install 3 radiators with 5 sections on each.

The calculator shows that the total power of the radiators was 14.8 kW. This means that a 15 kW water-heating boiler can cope with the provision of heating devices with heat.

Selection of pipes for the heating main

The main supplies heat carrier to all heating devices in the house. The modern market provides a choice of three types of pipes suitable for the main pipeline:

• plastic;
• copper;
• metal.

The most commonly used plastic pipes. Click on the photo to enlarge.

The most common type are plastic pipes. They are aluminum drain covered with plastic. This provides the pipes with special strength, as they do not rust from the inside and are not harmed from the outside. In addition, their reinforcement reduces the coefficient of linear expansion. They do not collect static electricity and do not require much experience to install.

Metal-based main pipes have many disadvantages. They are quite massive, and their installation requires experience with a welding machine. In addition, such pipes rust over time.

Copper main pipes are the best option, but they are also hard to work with. In addition to the difficulties of installation, they have high prices. If the calculation of the cost of heating easily fits into your budget, choose this option. In the absence of the necessary material resources, plastic pipes will be the best choice.

How is the heating system installed?

First you need to equip the heating devices. As a rule, radiators are mounted under windows, as hot air prevents cold air from entering windows. Installation of heating devices is carried out using a perforator and a level. No special equipment is required.

When installing heaters, it will be necessary to observe a single height for the placement of radiators, otherwise water will not be able to reach higher areas, and circulation will be disrupted.

Welding of plastic pipes. Click on the photo to enlarge.

Having installed heating devices, it is necessary to lay pipes to them. To install them, you will need tools such as construction scissors, a soldering iron and a tape measure. Before starting installation, you need to measure the total length of the pipes to be laid and calculate the presence of all plugs, bends and tees. Plastic pipes usually have notches with auxiliary lines, which helps to install correctly and accurately.

Important to know: when connecting pipes with a soldering iron, do not separate them after unsuccessful soldering, otherwise a leak may occur. You need to work with a soldering iron carefully, having previously trained on pieces of pipe that will no longer be needed during installation.

Additional devices

Based on statistics, a passive circulation heating system is able to effectively heat a room area not exceeding 110 m 2. For large rooms, it will be necessary to equip the boiler with a special pump, making the circulation of the coolant adjustable. Some manufacturers produce heat generators that are already equipped with a pump.

Following the above recommendations, you will be able to make an individual calculation of the heating system of a private cottage, as well as the calculation of the cost of the proposed equipment. To install a water heating system, you will not need a lot of labor (2-3 people) and special installation skills.

What parameters need to be calculated when designing an autonomous heating system? How is the heating system of a private house calculated in each case? In the article, we will provide the reader with all the necessary formulas, reference data and accompany the calculations with examples.

We have to find out how difficult it is to calculate the parameters of autonomous heating.

What do we think

What steps does the calculation of the heating system for a private house consist of?

• The total heat demand and the corresponding boiler output.
• Demand for heat energy of a separate room and, accordingly, the power of the heater in it.

Note: we have to touch on the methods for determining the thermal power for different heaters.

• Expansion tank volume.
• Circulation pump parameters.

Thermal power

Roughly estimate the need for heat in the house in two ways:

1. By area.
2. By volume.

Calculation by area

This technique is extremely simple and is based on SNiP half a century ago: one kilowatt of thermal power is taken per 10 square meters of area. Thus, a house with a total area of ​​100 m2 can be heated with a 10-kilowatt boiler.

The scheme is good in that it does not require climbing into the jungle and calculating the thermal resistance of enclosing structures. But, like any simplified calculation scheme, it gives a very approximate result.

Fast, simple, and... inaccurate.

There are several reasons:

• The boiler warms up the entire volume of air in the room, which depends not only on the area of ​​\u200b\u200bthe house, but also on the height of the ceilings. And this parameter in private housing construction can vary widely.
• Windows and doors lose much more heat per unit area than walls. If only because they are much more transparent to infrared radiation.
• The climatic zone also greatly affects heat loss through building envelopes. A doubling of the temperature delta between the room and the street will double the heating costs.

Calculation by volume with regional coefficients

It is for these reasons that it is better to use a slightly more complex, but much more accurate calculation scheme.

1. The base value is 60 watts of heat per cubic meter of heated space.
2. For each window in the outer wall, 100 watts are added to the calculated thermal power, for each door - 200.
3. The result obtained is multiplied by the regional coefficient:

Let's take the same house with an area of ​​​​100 square meters as an example.

However, this time we will stipulate a number of additional conditions:

• The height of its ceilings is 3.5 meters.
• The house has 10 windows and 2 doors in the outer walls.
• It is located in the city of Verkhoyansk (the average January temperature is 45.4 C, the absolute minimum is 67.6 C).

So, let's calculate the heating of a private house for these conditions.

1. The internal volume of the heated room is 100*3.5=350 m3.
2. The base value of the thermal power will be 350*60=21000 W.
3. Windows and doors exacerbate the situation: 21000+(100*10)+(200*2)=22400 watts.
4. Finally, the refreshing climate of Verkhoyansk will force us to double the already large heat output of heating: 22400 * 2 = 44800 watts.

As you can easily see, the difference with the result obtained by the first method is more than four times.

Heating appliances

The very methodology for calculating the heat demand for a separate room is completely identical to that given above.

For example, for a room of 12 m2 with two windows in the house we described, the calculation will look like this:

1. The volume of the room is 12*3.5=42 m3.
2. The basic thermal power will be equal to 42 * 60 \u003d 2520 watts.
3. Two windows will add another 200 to it. 2520+200=2720.
4. The regional coefficient will double the demand for heat. 2720*2=5440 watts.

• Manufacturers always indicate the heat output for convectors, plate radiators, etc. in the accompanying documentation.

• For sectional radiators, the necessary information can usually be found on the websites of dealers and manufacturers. In the same place, you can often find a calculator for converting kilowatts in a section.
• Finally, if you are using sectional radiators of unknown origin, with their standard size of 500 millimeters along the axes of the nipples, you can focus on the following average values:

In an autonomous heating system with its moderate and predictable coolant parameters, aluminum radiators are most often used. Their reasonable price is very pleasantly combined with a decent appearance and high heat dissipation.

In our case, aluminum sections with a power of 200 watts will need 5440/200=27 (rounded).

Placing so many sections in one room is not a trivial task.

As always, there are a couple of subtleties.

• With a side connection of a multi-section radiator, the temperature of the last sections is much lower than the first; accordingly, the heat flux from the heater decreases. A simple instruction will help to solve the problem: connect the radiators according to the “bottom down” scheme.
• Manufacturers indicate the heat output for a temperature delta between the coolant and the room at 70 degrees (for example, 90 / 20C). As it decreases, the heat flow will decrease.

A special case

Often, self-made steel registers are used as heating devices in private homes.

Please note: they attract not only by their low cost, but also by their exceptional tensile strength, which is very useful when connecting a house to a heating main.
In an autonomous heating system, their attractiveness is negated by their unpretentious appearance and low heat transfer per unit volume of the heater.

Let's just say - not the top of aesthetics.

However: how to estimate the thermal power of a register of known size?

For a single horizontal round pipe, it is calculated by a formula of the form Q = Pi * Dn * L * k * Dt, in which:

• Q is the heat flux;
• Pi - the number "pi", taken equal to 3.1415;
• Dn is the outer diameter of the pipe in meters;
• L is its length (also in meters);
• k is the thermal conductivity coefficient, which is taken equal to 11.63 W / m2 * C;
• Dt is the temperature delta, the difference between the coolant and the air in the room.

In a multi-section horizontal register, the heat transfer of all sections, except for the first, is multiplied by 0.9, since they give off heat to the upward flow of air heated by the first section.

Let's calculate the heat transfer of a four-section register with a section diameter of 159 mm and a length of 2.5 meters at a coolant temperature of 80 C and an air temperature in the room of 18 C.

1. The heat transfer of the first section is 3.1415*0.159*2.5*11.63*(80-18)=900 watts.
2. The heat output of each of the remaining three sections is 900 * 0.9 = 810 watts.
3. The total thermal power of the heater is 900+(810*3)=3330 watts.

Expansion tank

And in this case, there are two calculation methods - simple and accurate.

simple circuit

A simple calculation is utterly simple: the volume of the expansion tank is taken equal to 1/10 of the volume of the coolant in the circuit.

Where to get the value of the volume of the coolant?

Here are a couple of simple solutions:

1. Fill the circuit with water, bleed the air, and then drain all the water through the bleeder into any measuring vessel.
2. In addition, roughly the volume of a balanced system can be calculated from the calculation of 15 liters of coolant per kilowatt of boiler power. So, in the case of a 45 kW boiler, the system will have approximately 45 * 15 = 675 liters of coolant.

Therefore, in this case, a reasonable minimum would be 80 liters (rounded up to the standard value).

Exact scheme

More precisely, you can calculate the volume of the expansion tank with your own hands using the formula V = (Vt x E) / D, in which:

• V is the desired value in liters.
• Vt is the total volume of the coolant.
• E is the expansion coefficient of the coolant.
• D is the expansion tank efficiency factor.

Obviously, the last two parameters need comments.

The expansion coefficient of water and lean water-glycol mixtures can be taken from the following table (when heated from an initial temperature of +10 C):

Heating, C	Extension, %
30	0,75
40	1,18
50	1,68
60	2,25
70	2,89
80	3,58
90	4,34
100	5,16

The tank efficiency factor can be calculated using the formula D = (Pv - Ps) / (Pv + 1), in which:

• Pv is the maximum pressure in the circuit (setting pressure of the safety valve).

Hint: usually it is taken equal to 2.5 kgf / cm2.

• Ps is the static pressure of the circuit (it is also the tank charging pressure). It is calculated as 1/10 of the difference in meters between the level of the tank and the upper point of the circuit (an excess pressure of 1 kgf / cm2 raises the water column by 10 meters). A pressure equal to Ps is created in the air chamber of the tank before filling the system.

Let's calculate tank requirements for the following conditions as an example:

• The height difference between the tank and the upper point of the contour is 5 meters.
• The power of the heating boiler in the house is 36 kW.
• The maximum water heating is 80 degrees (from 10 to 90C).

So:

1. The tank efficiency coefficient will be equal to (2.5-0.5)/(2.5+1)=0.57.

1. The volume of coolant at the rate of 15 liters per kilowatt is 15 * 36 = 540 liters.
2. The coefficient of expansion of water when heated by 80 degrees is 3.58%, or 0.0358.
3. Thus, the minimum tank volume is (540*0.0358)/0.57=34 liters.

Circulation pump

How to choose the optimal parameters?

Two parameters are important for us: the pressure created by the pump and its performance.

In the photo - a pump in the heating circuit.

With pressure, everything is not simple, but very simple: a circuit of any length that is reasonable for a private house will require a pressure of no more than the minimum 2 meters for budget devices.

Reference: a difference of 2 meters makes the heating system of a 40-apartment building circulate.

The simplest way to choose the performance is to multiply the volume of coolant in the system by 3: the circuit must turn around three times per hour. So, in a system with a volume of 540 liters, a pump with a capacity of 1.5 m3 / h (rounded) is sufficient.

A more accurate calculation is performed using the formula G=Q/(1.163*Dt), in which:

• G - productivity in cubic meters per hour.
• Q is the power of the boiler or section of the circuit where circulation is to be provided, in kilowatts.
• 1.163 is a coefficient tied to the average heat capacity of water.
• Dt is the temperature delta between the supply and return of the circuit.

Sometimes performance is indicated in liters per minute. It's easy to count.

Conclusion

We hope that we have provided the reader with all the necessary materials. Additional information on how heating is calculated in a private house can be found in the attached video. Good luck!