How to calculate the power of a gas boiler for the given parameters of a heated room? I know at least three different ways, which give different levels of reliability of the results, and today we will get acquainted with each of them.
Why do we calculate the parameters specifically for gas heating?
The fact is that gas is the most economical (and, accordingly, the most popular) source of heat. A kilowatt-hour of thermal energy obtained by its combustion costs the consumer 50-70 kopecks.
For comparison, the price of a kilowatt-hour of heat for other energy carriers:
In addition to economy, gas equipment attracted by ease of use. The boiler requires maintenance no more than once a year, does not need kindling, cleaning the ash pan and replenishing the fuel supply. Devices with electronic ignition work with remote thermostats and are able to automatically maintain a constant temperature in the house, regardless of the weather.
Does the calculation of a gas boiler for a home differ from the calculation of a solid fuel, liquid fuel or electric boiler?
In general, no. Any heat source must compensate for heat loss through the floor, walls, windows and ceiling of the building. Its thermal power has nothing to do with the energy carrier used.
In the case of a double-circuit boiler supplying the house hot water for household needs, we need a reserve of power to heat it. Excess power will ensure the simultaneous flow of water in the DHW system and the heating of the coolant for heating.
We will be helped in this by the normative documentation of half a century ago. According to Soviet SNiP, heating should be designed at the rate of 100 watts of heat per square meter of heated space.
Let's, for example, calculate the power for a house measuring 6x8 meters:
The choice of boiler power according to the area of the heated room is simple, understandable and ... in most cases gives the wrong result.
Because he neglects a number of important factors that affect real heat loss:
IN apartment building heat loss is affected by the location of the living space relative to the outer walls: end and corner rooms lose more heat. However, in a typical cottage, all rooms have common walls with the street, so the appropriate correction factor is included in the base value of the heat output.
How to do the calculation of a gas boiler for heating a private house with your own hands, taking into account all the factors I mentioned?
First and foremost: in the calculation, we take into account not the area of \u200b\u200bthe house, but its volume, that is, the product of the area by the height of the ceilings.
| Image | Coefficient and climate zone |
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0,6-0,9 - for regions with an average January temperature of about 0 °C (Krasnodar Territory, Crimea). |
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1,2-1,3 - for the average temperature of the coldest month at -15-20 °C (Moscow and Leningrad regions). |
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1,5-1,6 - for areas with an average January temperature of -25-30 ° C (Novosibirsk region, Khabarovsk Territory). |
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2 - for -40 and below (Chukotka, Yakutia). |
Let's again calculate the boiler power for our house measuring 6x8 meters, specifying a few additional parameters:
9916*0.6=6000 (with rounding) watts.
As you can see, the complicated calculation scheme gave a result that is noticeably different from the previous one. How accurate is it?
The calculation will give a reliable result for a house, the quality of insulation of which approximately corresponds to the quality of insulation of Soviet-built houses. The scheme is based on the same 100 watts per square area, recalculated taking into account the standard ceiling height of 2.5 meters at 40 W / m3 and multiplied by a factor of 1.5 to compensate for the heat loss of a private house through the roof and floor.
How to determine the need for heat in a house with non-standard insulation?
The most universal formula for calculating the heat output of a boiler is Q=V*Dt*k/860.
In this formula:
How to choose the coefficient k?
Select its value for your conditions, guided by the following table:
| Image | Coefficient value and description of the building |
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3-4 - building without insulation (a warehouse made of profiled sheets, a panel house with walls made of planks in one layer) |
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2.0-2.9 - walls made of timber 10 cm thick or bricks 25 cm thick, wooden frames, single glazing |
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1,0-1,9 - brick walls 50 cm thick, double glazed windows |
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0.6-0.9 - facade insulated with foam plastic or mineral wool, plastic windows with triple or energy-saving double-glazed windows |
How to choose the value of the calculated outdoor temperature? In calculations, it is customary to use the temperature of the coldest five-day winter for a given region. Rare extreme frosts are not taken into account: when the thermometer falls below the usual levels, auxiliary heat sources (heaters, fan heaters, etc.) can be used.
Where can I get relevant information? The instruction is quite predictable: the necessary data can be found in SNiP 23-01-99, normative document dedicated to building climatology.
For the convenience of readers, I will give here a short excerpt from the text of SNiP.
| City | Temperature of the coldest 5 days of winter, °C |
| Maykop | -22 |
| Barnaul | -42 |
| Blagoveshchensk | -37 |
| Tynda | -46 |
| Shimanovsk | -41 |
| Arkhangelsk | -37 |
| Astrakhan | -26 |
| Ufa | -39 |
| Belgorod | -28 |
| Bryansk | -30 |
| Ulan-Ude | -40 |
| Vladimir | -34 |
| Vologda | -37 |
| Voronezh | -31 |
| Makhachkala | -19 |
| Irkutsk | -38 |
| Kaliningrad | -24 |
| Petropavlovsk-Kamchatsky | -22 |
| Pechora | -48 |
| Kostroma | -35 |
| Agatha | -55 |
| Turukhansk | -56 |
| St. Petersburg | -30 |
| Susuman | -57 |
| Moscow | -32 |
| Novosibirsk | -42 |
| Vladivostok | -26 |
| Komsomolsk-on-Amur | -37 |
| Yalta | -8 |
| Sevastopol | -11 |
Let's return to our example with a house in Sevastopol, once again clarifying a few details:
Let's start with the calculations.
As you can see, the correction for significant heat losses almost doubled the calculated capacity of the gas boiler.
It's very simple: a 20% reserve is included in the project for the operation of the second flow. In our case, the required power will be 11x1.2 = 13.2 kW.
To ensure a comfortable temperature throughout the winter, the heating boiler must produce such an amount of thermal energy that is necessary to replenish all the heat losses of the building / room. Plus, it is also necessary to have a small power reserve in case of abnormal cold weather or expansion of areas. We will talk about how to calculate the required power in this article.
To determine the performance of heating equipment, it is first necessary to determine the heat loss of the building / room. Such a calculation is called thermal engineering. This is one of the most complex calculations in the industry as there are many factors to consider.
Of course, the amount of heat loss is affected by the materials that were used in the construction of the house. Therefore, the building materials from which the foundation is made, walls, floor, ceiling, floors, attic, roof, window and door openings are taken into account. The type of system wiring and the presence of underfloor heating are taken into account. In some cases, even the presence household appliances which generates heat during operation. But such precision is not always required. There are techniques that allow you to quickly estimate the required performance of a heating boiler without plunging into the wilds of heat engineering.
For an approximate assessment of the required performance of a thermal unit, the area of \u200b\u200bthe premises is sufficient. In the very simple version for central Russia, it is believed that 1 kW of power can heat 10 m 2 of area. If you have a house with an area of 160m2, the boiler power for heating it is 16kW.
These calculations are approximate, because neither the height of the ceilings nor the climate are taken into account. For this, there are coefficients derived empirically, with the help of which appropriate adjustments are made.
The indicated rate - 1 kW per 10 m 2 is suitable for ceilings 2.5-2.7 m. If you have higher ceilings in the room, you need to calculate the coefficients and recalculate. To do this, divide the height of your premises by the standard 2.7 m and get a correction factor.
Calculating the power of a heating boiler by area - the easiest way
For example, the ceiling height is 3.2m. We consider the coefficient: 3.2m / 2.7m \u003d 1.18 rounded up, we get 1.2. It turns out that for heating a room of 160m 2 with a ceiling height of 3.2m, a heating boiler with a capacity of 16kW * 1.2 = 19.2kW is required. They usually round up, so 20kW.
To take into account climatic features, there are ready-made coefficients. For Russia they are:
If the house is located in the middle lane, just south of Moscow, apply a coefficient of 1.2 (20kW * 1.2 = 24kW), if in the south of Russia in Krasnodar Territory, for example, a coefficient of 0.8, that is, less power is required (20kW * 0.8 = 16kW).
Calculation of heating and selection of a boiler is an important stage. Find the wrong power and you can get this result ...
These are the main factors to be considered. But the values found are valid if the boiler will only work for heating. If you also need to heat water, you need to add 20-25% of the calculated figure. Then you need to add a "margin" for peak winter temperatures. That's another 10%. In total we get:
It can be seen from the examples that it is necessary to take into account at least these values. But it is obvious that in calculating the power of the boiler for a house and an apartment, there should be a difference. You can go the same way and use coefficients for each factor. But there is an easier way that allows you to make corrections in one go.
When calculating a heating boiler for a house, a coefficient of 1.5 is applied. It takes into account the presence of heat loss through the roof, floor, foundation. It is valid with an average (normal) degree of wall insulation - laying in two bricks or building materials similar in characteristics.
For apartments, different rates apply. If there is a heated room (another apartment) on top, the coefficient is 0.7, if a heated attic is 0.9, if an unheated attic is 1.0. It is necessary to multiply the boiler power found by the method described above by one of these coefficients and get a fairly reliable value.
To demonstrate the progress of calculations, we will calculate the power of a gas heating boiler for an apartment of 65m 2 with 3m ceilings, which is located in central Russia.
Now we round the result and get: 11 kW.
The specified algorithm is valid for the selection of heating boilers for any type of fuel. The calculation of the power of an electric heating boiler will not differ in any way from the calculation of a solid fuel, gas or liquid fuel boiler. The main thing is the performance and efficiency of the boiler, and heat losses do not change depending on the type of boiler. The whole question is how to spend less energy. And this is the area of \u200b\u200bwarming.
When calculating heating equipment for apartments, you can use the norms of SNiPa. The use of these standards is also called the calculation of boiler power by volume. SNiP sets the required amount of heat for heating one cubic meter air in standard buildings:
Knowing the area of \u200b\u200bthe apartment and the height of the ceilings, you will find the volume, then, multiplying by the norm, you will find out the power of the boiler.
For example, let's calculate the required boiler power for rooms in a brick house with an area of 74m 2 with ceilings of 2.7m.
It is easy to calculate the power for the same room, but already in a panel house: 199.8 * 41W = 8191W. In principle, in heating engineering they always round up, but you can take into account the glazing of your windows. If the windows have energy-saving double-glazed windows, you can round down. We believe that double-glazed windows are good and we get 8kW.
The choice of boiler power depends on the type of building - brick heating requires less heat than panel
Next, you need, as well as in the calculation for the house, to take into account the region and the need to prepare hot water. The correction for abnormal cold is also relevant. But in apartments, the location of the rooms and the number of storeys play a big role. You need to take into account the walls facing the street:
After you take into account all the coefficients, you will get a fairly accurate value that you can rely on when choosing equipment for heating. If you want to get an accurate heat engineering calculation, you need to order it from a specialized organization.
There is another method: to determine the real losses with the help of a thermal imager - a modern device that will also show the places through which heat leaks are more intense. At the same time, you can eliminate these problems and improve thermal insulation. And the third option is to use a calculator program that will calculate everything for you. You just need to select and / or enter the required data. At the output, get the estimated power of the boiler. True, there is a certain amount of risk here: it is not clear how correct the algorithms are at the heart of such a program. So you still have to at least roughly calculate to compare the results.
We hope you now have an idea of how to calculate the power of the boiler. And it doesn’t confuse you that it is, and not solid fuel, or vice versa.
You may be interested in articles about and. In order to have a general idea of the mistakes that are often encountered when planning a heating system, watch the video.
To answer this question, only data on its cubic capacity is not enough. To choose the right heating equipment, you need information about the heat loss of the house.
To ensure proper comfort in using the DHW system, the power of a double-circuit boiler must be significantly greater than when the boiler only heats the house.
When building or reconstructing a house, it becomes necessary to select the power of the boiler to provide the home with heat and hot water.
The main information needed to select the power of the boiler is the heat loss of the house, which it must compensate for. They need to be calculated. Each country has adopted a specific methodology for calculating heat losses, which takes into account local climatic conditions.
In Ukraine, there is a methodology set forth in DBN B 2.6-31:2006 "Thermal insulation of structures", which contains requirements for thermal performance of enclosing structures of houses and structures and the procedure for their calculation.
When ordering a house project from an architect, you have the right to demand that the project contains the results of such calculations. Based on them, you can choose not only a boiler, but also heating equipment for all rooms. With the use of a computer program. Calculating heat loss is facilitated by computer programs, free versions of which are distributed by many installation companies. Thanks to advanced additional features the program allows you to perform calculations even for people who have never encountered design before. But due to the lack of relevant experience, they will most likely need much more time to carry out the calculation. According to the results of such calculations, it is better to consult with a specialist.
With the help of a questionnaire. If you do not have a project with heat losses calculated by the architect (designer), you can try to determine them yourself using simplified calculation methods. Sufficiently accurate for small private houses are still not very common with us, but very practical questionnaires.
They raise questions regarding: the cubic capacity of the house, the material of the walls and their thickness; insulation material and its thickness; the number of windows and their sizes, the number of chambers in double-glazed windows and others. For each of the questions, there are several possible answers. You need to choose the one that best describes your home. Each answer corresponds to a certain number. Performing mathematical operations with these numbers according to the attached instructions, we will get a value that describes the heat loss of your home. Its accuracy is quite acceptable for selecting the power of the boiler. Filling out the questionnaire and calculations takes only a few minutes. Approximately. Most simple method calculating the heat loss of a house is to determine them using a conditional coefficient, which is approximately:
130-200 W / m - for houses without thermal insulation;
90-110 W / m - for houses with thermal insulation built in the 80-90s of the XX century;
50-70 W/m2 - for houses with modern windows, well insulated and built since the late 1990s.
Heat loss is determined by multiplying the value of the coefficient by the area of the house. These calculations are very approximate, they do not take into account the number and size of windows, the shape of the house and its location - factors that significantly affect the heat loss of the house. Such calculations should not be the main criterion when choosing a boiler, they can be used to evaluate the designer's calculations. Unfortunately, the difference between these results can be significant, so only a gross error can be detected in this way.
« Approximately". More recently, when fuel was cheap, houses were practically not insulated, and the windows were leaky and no one thought about the concept of energy saving - the installers selected the boiler power very simply - 1 kW for every 10 m2 of the house area. But today you need to select a boiler, based on strict calculations.
A double-circuit boiler with a power of 18 kW allows you to comfortably use hot water for only one person. Opening a second tap at this time will lead to a significant decrease in pressure and temperature of hot water. A large family will experience discomfort from the operation of the hot water supply that such a boiler provides. Purchasing a larger boiler, for example 28 kW, may eliminate the discomfort of using hot water, but you need to weigh whether the minimum power of such a boiler will be too large compared to the heat demand for heating the house.
In order for the boiler to work in the most suitable mode for it, that is, with a constant [approximately the same] power, hydraulic systems with a four-way mixing valve.
A similar effect, but for less money, can be achieved by installing the so-called thermo-hydraulic distributor
The calculated heat loss of the house is equal to its maximum heat demand, necessary to maintain a comfortable temperature in the house - usually + 20 ° C. The maximum heat demand occurs on the coldest days, when the outside temperature drops (depending on the temperature zone) to -22°C. It should be borne in mind that such frosts occur only a few days a year, and sometimes they are not observed for several years in a row. However, the boiler must function effectively throughout the heating season, when the temperature fluctuates most often near zero. In this case, a boiler of half the (than the calculated) power is enough to heat the house. Therefore, it often makes no sense to buy a boiler with a larger capacity - not only due to its higher price, but also taking into account the decrease in the efficiency of its operation when the heat demand is much lower than the calculated one. The lack of heat on cold days can be made up by other sources, such as a fireplace or electric heaters.
How to combine high power with low demand.
It is best if the boiler operates at a constant, rated power throughout the entire time. But the need for thermal energy (depending on outdoor temperature) changes all the time. How to solve this problem? Mixing valves. One way to do this is to use hydraulic systems with a four-way mixing valve or with a thermo-hydraulic distributor. In such systems, the temperature of the water entering the radiators is not regulated by changing the power of the boiler, but by changing the position of the control valve and the performance of the circulation pumps. Thanks to this, the boiler constantly works in optimal conditions. This is a very good, but rather expensive solution.
Multistage burners.
In small and not very expensive systems with gas or oil boilers, the issue of adapting the boiler output to the actual heat demand is solved using multi-stage burners. When full power is not needed, a boiler equipped with such a burner operates at a lower power (lower burner stage). A more perfect option are burners with smooth power control, the so-called modulation. They are widely used in hinged gas boilers. In liquid fuel boilers, they are much less common. A modulating burner boiler is a cheaper and less troublesome option than a mixing valve system. None required additional elements– all the necessary fittings are mounted in the boiler body. Power adjustment is also possible in modern solid fuel boilers that work on pellets and are equipped with automated system fuel supply (unfortunately expensive).
A boiler with a modulating burner generates energy equal to the current heat demand. At first glance, one might assume that when choosing such a boiler, it is not necessary to accurately determine the heat loss of the house. After all, knowing them only approximately, you can buy a boiler of greater power, which in any case will work with the power required at a certain moment. Unfortunately, in practice, modulating the power of the boiler does not completely solve all issues. Immediately after switching on, the boiler starts to work with maximum power, after a certain time, its automation begins to reduce power to the optimum level. If a large boiler is to be operated in a small system, then in conditions where the heat demand is low (i.e. outside temperature near zero or above), the water in the system will heat up even before the burner reaches required level modulation and the boiler will turn off. The water in the system will quickly cool down and the situation will repeat itself. The boiler will operate in pulse mode - as if it was equipped with a single-stage burner high power. Power modulation is possible only in a limited range, which is usually no less than 30% of the maximum power. Therefore, too high a maximum boiler output will lead to difficulties in adapting its performance at a higher outside temperature. There are boilers with a wider power modulation range, but these are more expensive condensing boilers.
Sufficiently large difficulties arise in the selection of a liquid fuel boiler for small house. To compensate for the heat loss of a well-insulated house with an area of about 150 m: usually a boiler with a capacity of no more than 10 kW is enough, and the power of liquid fuel boilers on the market is at least twice as high. The operation of a liquid fuel boiler in a pulsed mode (that is, frequent switching on and off) is even more unfavorable for it than for a gas boiler. Immediately after turning on the oil burner, a lot of soot and products of incomplete combustion are released from the combustion products, which clog the combustion chamber of the boiler. Therefore, it will have to be cleaned frequently, otherwise the soot layer will impede heat transfer, and the efficiency of the boiler will decrease, that is, it will consume more fuel.
Most of the described problems that arise can theoretically be avoided by choosing a boiler with a capacity that does not exceed, and even slightly below, the calculated heat loss of the house. But in practice, the energy of the boiler is usually used not only for the central heating system, but also for heating the water of the DHW system. In small, well-insulated houses, the power needed to heat the house is much less than that needed to quickly heat the required amount of DHW water. It complicates the problem optimal choice boiler.
A double-circuit boiler heats water for the DHW system in a flow-through manner. The time for water to flow through the heat exchanger is short, so the boiler must have a high power in order to heat a sufficient amount of water during this time. double-circuit boilers have a power of 18 kW, because this is the minimum that still allows you to prepare a sufficient (for taking a shower) amount of hot water. If such a boiler is equipped with a modulating burner, it will be able to operate with a minimum power of about 6 kW, that is, close to the maximum heat loss in a well-insulated house with an area of about 100 m2. In practice, during most of the heating season, the power requirement for heating such a house will most likely be about 3 kW. Therefore, this is not an ideal, but acceptable situation.
One of the ways to reduce the required power of a double-circuit boiler is to use a storage tank for domestic hot water. Then the boiler can heat water more slowly, because after opening the tap there is a supply of warm water in the storage tank. The larger its volume, the longer it can replenish the missing amount of hot water prepared by the boiler. Therefore, the boiler power may be lower.
Single-circuit boiler with a boiler.
Boiler volume indirect heating (storage water heater with a heat exchanger), which is connected to a single-circuit boiler, is usually more than 100 liters. Due to this, the simultaneous use of hot water by several consumers does not lead to the exhaustion of its supply for several minutes, therefore, the power of the boiler operating in conjunction with the water heater may be lower than the power of a two-circuit boiler. Therefore, we can assume that the power of the boiler, which is necessary to compensate for the heat loss of the house, is also sufficient to heat the water in the boiler. However, when choosing the power of a single-circuit boiler, it is better to calculate how long it will take to heat the water in the boiler. This can be done using the formula:
T \u003d mc B (t 2 - t 1) / P,
where: T - water heating time (s); m is the mass of water in the boiler (kg); c B - specific heat capacity of water - 4.2 kJ / (kg x K); t2 is the temperature to which the water must be heated (°C); t 1 - initial water temperature in the boiler (°C); P - boiler power (kW).
For example: the heating time of water having a temperature of 10 ° C (it is generally accepted that this is the temperature of cold water entering the water heater) to 50 ° C in a 200-liter boiler with a 12 kW boiler will be: 200 x 4.2 x (50 - 10J/12 = 2800 (s) = 46.7 (min).
It's long enough, especially considering that during the heating of water in the boiler, from the boiler operating at full capacity, warm water does not enter the central heating system. During this time, the rooms may become cool.
However, it should be noted that the situation in which the entire volume of water has a temperature of 10°C can only occur after the boiler has been switched off for at least a few hours. On practice cold water enters the boiler as the hot water is consumed. Even if it is used intensively, for example, when filling the bathtub to the brim very quickly, about half of the hot water will be used from such a large boiler. After that, the temperature of the water (hot, mixed with cold) in the boiler will be about 30°C. In this case, the water heating time will be 23 minutes and it can be considered satisfactory. One-time hot water consumption in a single-family home is usually much lower, so the water in the boiler will heat up even faster.
Solution to the problem. The problem of sharing boiler capacity for the CH system and for DHW water can be solved in a radical way: by purchasing two independent devices - a boiler for the central heating system and a water heater for hot water supply. But this is definitely an expensive solution.
What happens if the boiler has too much power?
Its performance can be adjusted only by changing the amount of air entering the furnace. When operating at a power lower than the nominal one (that is, with a lack of air), the fuel will not burn completely, so its consumption will be greater. In addition, unburned connections will go into the chimney, causing it to clog more quickly.
Gas or oil boiler, working with modern system CH (containing not a large number of water), after turning on the burner, very quickly heats the water in the system to the desired temperature and turns off the burner. The burner operation time will be shorter, the higher the boiler power. It may happen that it will be too short and the combustion products will not be able to heat the chimney up to normal temperature. Then condensate will fall in the chimney, which, combining with other products of combustion, forms acids that destroy the chimney, and sometimes the boiler itself.
If the burner is running for a long time, the flue gases heat up the chimney up to high temperature, thanks to which the condensate will not form, and the condensate that has arisen in the initial phase of the burner operation will evaporate.
With frequent switching on and off, the boiler consumes more fuel than during continuous operation, because with each switching on, part of the energy will be spent on heating the elements of the boiler and the chimney. In addition, frequent temperature changes adversely affect its strength.
An overly powerful solid fuel boiler uses more fuel, and the heat energy in any case will not be fully used for heating
An overly powerful gas boiler will often turn on, which reduces its energy efficiency and accelerates the wear of the elements.
If you nevertheless bought a boiler whose power is much higher than the calculated heat demand for heating the house, its working conditions can be significantly improved by installing a storage tank (also called a buffer tank).
This solution, used in systems with solar collectors, is recommended to be used primarily in systems with solid fuel boilers. Thanks to the battery, regardless of the short-term heat demand, the boiler can be operated with the rated output at which it has the highest efficiency. The storage tank is completely filled with water.
In systems with a solid fuel boiler its optimal volume can be determined from the calculation: 10 liters for each square meter heated area. When it is relatively warm outside, automatic control valves limit the flow of hot water to the radiators, directing it to the heat exchanger of a well-insulated storage tank, heating the water there. Its large volume (for a house with an area of 100 m: it should be 1000 l) during the operation of the boiler accumulates a large amount of excess heat energy from the system.
When the fuel in the boiler burns out and its furnace cools down, warm water from the buffer tank will begin to flow into the radiators. As a result, the heating system will still function properly.
Heating systems with a large amount of water have a significant thermal inertia, due to which the burners of gas and oil boilers work in more favorable conditions. The periods of operation of the burner and the breaks between them are longer - it takes longer to heat more water, which then cools down longer. However, the response of the system to changes in outside temperature is slower, which makes it more difficult to maintain a comfortable temperature in the rooms.
Compared to electrical heating appliances, own heating system is more advantageous in terms of cost savings, and in maximum convenience when heating rooms.
Efficiency and profitability heating system in the house depends on correct calculations, adherence to precise rules and instructions.
Calculation of heating by the area of the house is a laborious and complex process. Don't skimp on materials. Quality equipment and its installation affects the financial budget, but then serves the house well and comfortably.
When equipping the house with a heating system, construction works and installation of heating must go strictly according to the project and taking into account all safety regulations for use.
The following points should be taken into account:
Subject to all the above rules and calculations for heating, some knowledge in the field of engineering is required. But there is also a simplified system - the calculation of heating by area, which can be done independently, again, adhering to the rules and complying with all norms.
If there is gas in the house, then the most the best way- this a gas boiler. In the absence of a centralized gas pipeline, we choose an electric boiler, a heat generator using solid or liquid fuel. Taking into account regional characteristics, access to the supply of materials, it is possible to install a combined boiler. Combined generator heat will always maintain a comfortable temperature, in any emergency and force majeure situations. Here you need to start from a simple type of operation, the heat transfer coefficient.
After determining the type of boiler, it is necessary to calculate the heating according to the area of \u200b\u200bthe room. The formula is simple, but it takes into account the temperature of the cold period, the heat loss coefficient for large windows and their location, the thickness of the walls and the height of the ceilings.
Each boiler has a certain power. With the wrong choice, the room will be either cold or excessively hot. Thus, if the specific power of the boiler per 10 cubic meters. taking into account the area of the heated room of 100 sq.m., you can choose the most optimal heat generator.
From the formula used by engineers, Wcat = (SxWsp)/10, kW. – it follows that the boiler with a capacity of 10 kW heats a room of 100 sq.m.
To make it more clear, let's solve the problem using the example of specific numbers. If we assume that room area 14 sq.m. And ceiling height 3 meters, the volume is determined by multiplication.
14 x 3 = 42 cubic meters.
In central Russia, Ukraine, Belarus, thermal power per cubic meter corresponds to 41 W. We determine: 41x 42 \u003d 1722 watts. Found out that for a room of 14 sq.m. need a 1700W heatsink. Each individual section (rib) has a power of 150 watts. By dividing the results obtained, we obtain the number of sections required for the acquisition. The calculation of heating by area is not the same everywhere. For premises over 100 sq.m. required circulation pump installation, which serves as a "forcer" of the movement of the coolant through the pipes. Its installation takes place in the opposite direction from the heating devices to the heat generator. Circulation pump increases the life of the heating system, reducing the contact of hot coolants with appliances.
When installing a heating system warm floor» the coefficient of heating of the house increases many times. You can connect the underfloor heating system to existing types of heating. A pipe is removed from the heating radiators and floor heating wiring is supplied. This is the most convenient and profitable option, taking into account the savings in time and money.
The heating boiler is the central device of the heating system. For its operation with maximum performance and in order to avoid excessive energy consumption, an accurate calculation of the heating boiler power is necessary. A properly sized heat generator will be able to maintain optimal functionality with much lower maintenance costs.
The power of the heater requires a uniform supply of heat transfer to the network. It is designed to supply heat to buildings different size, be it a multi-storey building or a country house.
For optimal heating a one-story cottage, you do not need to purchase an overly powerful boiler, which is designed to heat a 3-4-story building.
The basis for the calculation is the area and dimensions of the building. How to calculate the power of the boiler, taking into account other parameters?
The calculation method is specified in building codes and regulations II-3-79 (SNiP). In this case, the following characteristics must be taken into account:
For the most accurate calculations, the presence of household equipment (computer, TV, electric stove, etc.) and internal lighting that can generate heat are often taken into account. But it doesn't make any practical sense.
Every 10 m² of a private house with average thermal insulation, standard climatic conditions of the region and a typical ceiling height (approximately 2.5-3 m) will require about 1 kW for heating.
More than 20% must be added to the power of the heating boiler, which is designed for joint operation in the heating and water supply system.
The unstable pressure in the boiler and the heating main will require the equipment with a special device with a reserve capacity, which exceeds the calculated values by about 15%.
The power of the heating boiler, which is connected to the heating system using a heat carrier (hot water), must also contain a reserve of more than 15%.
Insufficiently high-quality thermal insulation leads to the loss of heat energy in the following volumes:
For an approximate calculation, there is an elementary formula: W \u003d S × Wsp, where
W is the power of the unit;
S - the size of the building area in m², taking into account all the premises for heating;
Wsp is a standard indicator of specific power, which is used when calculating in a specific climatic region.
The standard value of specific power is based on the experience of using various heating systems.
The average information is obtained from the housing and communal services officer in your area. After that, multiply this value by the total area of \u200b\u200bthe building, and you will get the average indicator of the required boiler power.
Gas is the most common type of fuel. How to calculate the power of a gas boiler? Consider an example calculation for a building with an area of 150 m², which is supposedly located in the Krasnoyarsk Territory. The calculation is made for a heating system with natural circulation without constant pressure from the pump. The specific power in the region under consideration is 0.90 kW/m².
150 m² / 10 m² = 15 is an intermediate calculation factor, which assumes that 1 kW of the heating output of the unit is required per 10 m² of heated space.
15 × 0.90 kW/m² = 13.5 kW.
As a result, the average value of thermal energy required by a specific building with average statistical thermal insulation and climatic indicators was obtained.
If you take into account the use of hot water for the bathroom and kitchen, you will need to add at least 20% to the power: 13.5 + 13.5 × 0.2 = 16.2 kW.
It is worth paying attention to the fact that the pressure in the boiler and the heat main can be unstable, for this you need to add another 15% to the power: 16.2 + 13.5 × 0.15 = 18.225 kW.
Considering that a certain leakage of thermal energy cannot be avoided, it is necessary to round the result obtained up. It turns out that in order to provide heating for a particular building using a gas-fired heating unit, a boiler with a minimum power of 19 kW is required.
Power calculations for gas-fired units are most often performed during the planning period of the building. The reason for this is the initial laying in the project of the location of heating devices, openings for air exchange, a chimney, as well as a separate room for a heating installation.
If you need to consider heating in an existing building that does not have necessary conditions to place the unit on gas fuel, it will be necessary to install an alternative heating system. An electrical installation is well suited for its role, the calculation of the power of which is carried out according to similar calculations.
In addition to the above calculations, the calculation of the thermal power of the boiler can be done by a calculator specially designed for this. It includes such parameters as the total area of the room, its height, type of windows, etc. To find out the thermal power, it is necessary to enter the required indicators into the program, having previously found out their exact value.
Calculating the required power for heating a private house is not such a difficult task, especially if you use the calculator program. It can be handled by anyone who wants to save money and provide optimal heating without extra costs thermal energy.
