Making the right power calculation of the gas heating boiler
One of the first parameters that you pay attention to when choosing heating equipment is the output. Calculation of the capacity of the gas heating boiler, perform in several ways. From accurate calculations, depends on the comfort during operation.
Why count when you can buy a boiler with extra power?
Sometimes boilers have a reserve capacity. It is good when the reserve is not more than 25%. Especially when the family plans to develop the area: to complete the pool, sauna, or other heated area. When the required capacity is exceeded significantly, the owner spends extra money, and the equipment operates in an abnormal mode:
- Breaks down or malfunctions;
- The efficiency of the system decreases;
- Boiler of higher capacity costs more;
- fuel is consumed than needed to heat your home;
- You’ll need a more powerful and expensive pump;
- It will be very hot in the house;
- Automatic regulation is hampered, the boiler can boil;
- Boiler begins to rattle. If the heater is to be turned on and off in a short period of time, the parts of the equipment will wear out;
- Condensation appears in the chimney. When burning condensate reacts with emissions and acid is formed. It destroys the chimney and sometimes the boiler.
Conclusion: more fuel is wasted with frequent switching on and off than with continuous operation. Buying a boiler with excess capacity not only makes no sense, but is also bad for the budget and equipment.
How the boiler output depends on the area. how to calculate correctly
In most cases, use an approximate calculation of the thermal capacity of the boiler unit on the heating area, for example, for a private home:
Such calculations may be suitable for a not very large building with an insulated attic floor, low ceilings, good thermal insulation, double-glazed windows, but no more.
It is better not to do according to old calculations. Source
Unfortunately, these conditions correspond only to a small number of buildings. In order to carry out the most thorough calculation of the boiler capacity indicator, it is necessary to consider a full package of interrelated values, including:
- atmospheric conditions in the area;
- the size of the residential building;
- heat conductivity coefficient of the wall;
- actual thermal insulation of the building
- The system of regulating the power of the gas boiler;
- The amount of heat required for DHW.
Calculation of the one-circuit heating boiler
Calculating the capacity of a single-circuit boiler wall or floor modification of the boiler, using the ratio: 10 kW per 100 m2, you need to increase by 15-20%.
For example, it is necessary to heat a building with an area of 80 m2.
Calculation of the power of the gas heating boiler:
In the case where the trade network does not exist the required type of devices, purchase a modification with a larger size of the kW. Such a method will go for single-circuit heating sources, without the load on the hot water supply, and can be the basis for calculating the consumption of gas for the season. Sometimes, instead of the living area, the calculation is made taking into account the volume of the apartment building and the degree of insulation.
For individual rooms built according to a typical project, with a ceiling height of 3 m, the calculation formula is quite simple.
This variant takes into account the area of the building (P) and the coefficient of specific capacity of the boiler unit, depending on the climatic location of the object.
Consequently, the formula for the calculation is as follows: Mo=PUMC/10
For example, the required capacity of the heating source for a building of 80 m2, located in the northern region:
If the owner will install a two-circuit boiler unit, for heating and DHW, professionals advise to add to the obtained result another 20% of the power to heat water.
How to calculate the capacity of a two-circuit boiler
Calculation of the heat output of a two-circuit boiler unit is performed on the basis of the following proportion:
10 m2 = 1,000 W 20% (heat loss) 20% (DHW heating).
In the case of a building with an area of 200 m2, the required size would be: 20.0 kW 40.0% = 28.0 kW
This is an approximate calculation, it is better to clarify the norms of water consumption of DHW per person. These data are given in SNIP:
In the technical documentation to the water heater specifies what heat output of the boiler is needed to ensure high quality water heating.
For the heat exchanger for 200 liters will be sufficient heater load of approximately 30.0 kW. After calculating the capacity, sufficient for heating, at the end of the total add up.
Calculating the power of the indirect heating boiler
In order to balance the required capacity of single-circuit gas-fired unit with a boiler of indirect heating, it is necessary to establish how much heat exchanger will be needed to provide hot water to the tenants of the house. Using the data on the standards of hot water consumption can be easily established that the flow rate per day for a family of 4 people will be 500 liters.
The performance of the indirect water heater depends directly on the area of the internal heat exchanger, the more the size of the coil, the more heat energy it transfers to water per hour. You can detail such information by studying the characteristics on the passport of the equipment.
There are optimal ratios of these values for the average power range of indirect heating boilers and the time to obtain the desired temperature:
When choosing a water heater, it is recommended that it heats water for about half an hour. Based on these requirements, the 3rd variant is preferable.
Is it necessary to select a boiler with excessive power
Many experts recommend making a selection of the boiler, according to the area of the room and other parameters. You should not select a device with excessive power for two reasons:
- Such a boiler will work excessively and can break down quickly;
- The device is more expensive and even in economy mode will use more gas than it should.
Therefore, it is not rational to purchase equipment that will not be used, as prescribed by the operating manual. In addition, when the boiler is not working at full capacity, not on the optimal program, the parts wear out faster.
It is worth noting that a low-powered unit is also not suitable. It will work at full power and in excess of the specified rate. As a result, not only will not be achieved the required temperature standard, but the unit will be broken because of the wear and tear of parts.
Please note! It is important to accurately calculate the necessary power of the boiler before buying it or consult with a competent specialist, who will help yourself to calculate all the individual dimensions and parameters of the house.
Calculation of boiler output by area
For a rough estimate of the required capacity of the thermal unit is sufficient area of the premises. In the simplest version for the middle zone of Russia is that the power of 1 kW can heat 10m 2 area. If you have a house area of 160m2, the boiler capacity for its heating 16kW.
These calculations are approximate, because they do not take into account the height of the ceilings or the climate. For this, there are experimentally derived coefficients by which we make appropriate adjustments.
The listed figure of 1 kW per 10 m2 is suitable for 2.5 m to 2.7 m ceilings. 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 height of 2.7 m and obtain the correction factor.
Calculation of boiler output by area is the easiest way
E.g. 3,2 m high ceilings. Let’s calculate the coefficient: 3,2m/2,7m=1,18 rounded, we get 1,2. It turns out that for the heating of a room 160m2 with ceiling height 3,2m requires a boiler capacity 16kW1,2 = 19,2kW. Generally rounded upwards, so 20kW.
To consider the climatic features there are ready-made coefficients. For Russia they are as follows:
If the house is in the middle belt, just south of Moscow, apply a factor of 1.2 (20kW1,2 = 24kW), if in the south of Russia in the Krasnodar region, for example, the factor is 0.8, that is, the power required less (20kW0, 8 = 16kW).
Calculation of heating and boiler selection is an important step. Find the wrong wattage and you might get a result like this
These are the main factors that you need to consider. But the found values are true, if the boiler will work only for heating. If you also need to heat water, you need to add 20-25% of the calculated figure. Then we need to add a “margin” for peak winter temperatures. That’s another 10%. Total we get:
- For heating a house and hot water in the middle belt 24kW20%=28,8kW. Then the cold reserve is 28.8kW10%=31.68kW. Rounded up we get 32kW. If you compare with the original figure of 16 kW, the difference is two times.
- The house in Krasnodar region. Let’s add the power for hot water heating: 16kW20%=19,2kW. Now the “reserve” for the cold 19,210%=21,12 kW. Rounded up: 22kW. The difference is not so striking, but also enough.
From the examples you can see that at least these values must be taken into account. But it is obvious that in calculating the boiler power for the house and apartments, the difference should be. You can go the same way and use the coefficients for each factor. But there is a simpler way, which allows you to make adjustments at once.
When calculating the boiler heating for the house, the coefficient of 1.5 is applied. It takes into account the presence of heat loss through the roof, floor, foundation. Fair enough for the average (normal) degree of insulation of the walls masonry in two bricks or similar building materials on the characteristics.
For apartments other coefficients are applied. If there is a heated room above (another apartment) coefficient 0.7, if the heated attic 0.9, if unheated attic 1.0. It is necessary to multiply the capacity of the boiler found according to the above method by one of these coefficients and you will get a sufficiently reliable value.
To demonstrate the calculations, calculate the capacity of gas heating boiler for an apartment 65 m2 with 3 m ceilings, which is located in the middle belt of Russia.
- Determine the power required by area: 65m2 /10m2=6.5kW.
- Let’s correct for the region: 6,5kW1,2=7,8kW.
- The boiler will heat water, so we add 25% (we like it hotter) 7,8 kWt1,25=9,75 kWt.
- Let’s add 10% for the cold: 7,95kW1,1=10,725kW.
Now round up and get the result: 11 kW.
The above algorithm is true for the selection of heating boilers for any fuel type. Calculation of electric heating boiler capacity will not differ from the calculation of solid fuel, gas or liquid fuel boiler. The main thing is the boiler’s output and its efficiency, and the heat loss does not change. The question is how to use less energy. And this is the area of insulation.
How to calculate the output of the boiler for heating?
Stand-alone heating in a private home is convenient, affordable and generally efficient. But only if the equipment is chosen correctly. We are talking not only about the types of boilers, but also the necessary capacity of the system. In this article we will share with you how to calculate the capacity of the boiler for heating, how to make the necessary calculations and whether it is worth doing it yourself.
- boiler with too much power reserve. unjustified heating costs;
- Insufficient capacity. lack of heat in an apartment or private home.
Therefore, this issue must be approached with particular care.
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Power according to the building code
When calculating the capacity of the heating boiler for the apartment, focus on the norms of SNiP. This method is also called “calculation of power by volume”. SNIP shows the amount of heat needed to heat one cubic meter of air in typical buildings, namely: in order to heat 1 cubic. meter in a panel house, it will take 41 watts, and in a brick house. 34 watts.
If you know the height of the ceiling and the area of the apartment, you can calculate the volume. Then multiply this number by the above-mentioned norm and you get the necessary boiler capacity, regardless of the type of fuel. this rule works for apartment heating, too.
We propose to perform the calculations and find out the boiler output for the apartment with an area of 74 square meters. The ceiling height is 2.7 meters, which is located in a brick house.
First step: calculate the volume. 74 m22.7 m=199.8 cubic meters. meters.
The second step: calculate the amount of heat according to SNIP. 199.834 W=6793 W. The figure should be rounded upwards and converted to kilowatts, this will be the number you need.
Let’s assume that we need to calculate the same figure for the apartment located in a panel building. Then the formula will look like this: 199,841 W=8191 W. As you have already noticed, all figures on the thermal engineering are rounded upward, but in this case, if we take into account the presence of good plastic windows, the power can be calculated as 8 kW.
This is not the final figure. Then you need to consider indicators such as the region of residence and the need to heat water with a boiler. No less important is 10% correction for abnormal cold in winter. However, in apartments, unlike houses, very important indicators such as the location of the rooms and the number of floors. It is important to take into account how many walls in the apartment are external. If there is only one outer wall, the coefficient is 1.1, if two. 1.2, if three. 1.3.
Thanks to the calculations, you will get the final value of the capacity of the heater, when you take into account all the above-mentioned indicators. If you want to get a reliable thermal calculation, experienced professionals recommend contacting the specialized organizations that specialize in this.
Calculator for calculating the capacity of the heating boiler
Capacity of the boiler is one of the most important characteristics of heating equipment. Excess power will affect the overpayment for the boiler, the lack. the inability of the equipment to heat the living space or heat water in the DHW system. Therefore, before choosing a boiler, we propose to estimate its parameters not without the help of our online calculator to calculate the capacity of the heating boiler. Let’s try to understand the values that you have to enter to get a reliable result.
Principle of operation of the gas boiler 24 kW dual circuit
The main characteristic of the heating gas boiler. its thermal capacity. For the two-circuit option is no less important capacity of the hot water system (DHW). Calculations show that for trouble-free provision of hot water standard for all dwellings, kitchen and bathroom, you need a capacity of at least 23 kW. In this regard, it is these devices, and, in particular, the gas boiler 24 kW, in the two-circuit version, the most widely represented in the trade.