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How to calculate the needed boiler power?

The purchase of a boiler should be preceded by calculations of the heat demand of a building. Selection of the appropriate power is extremely important. The furnace must provide optimal air temperature conditions under all conditions.

What is boiler power?

Boiler power is a parameter that is specified in units of power - kW. It provides information on what maximum power can be achieved by the device when using fuel with energy parameters recorded in the technical documentation by the manufacturer. There are many boilers on the market with different power outputs, you can find smaller models, such as 6 kW, or much larger ones, such as 40 kW. This allows everyone to choose the precise boiler that will heat the entire area. The power of the stove can be both nominal and maximum. Therefore, it is important to know that nominal power output is the value read from the nameplate along with the efficiency rating, that is, the energy that the boiler is able to produce according to the design.

How to choose the power of the boiler?

It is extremely important to correctly select the power of a boiler for pellets, eco-pea or any other type of fuel. Therefore, it is worth making calculations to decide on the appropriate stove based on them. Owners of new buildings have an easier task, since architects include in the design data about the heating power that the stove should have in order to optimally heat the house. In case you do not have such calculations, it is necessary to make them. In such a situation, you can hire a professional to accurately calculate the appropriate heating power or do it yourself.

Check out our eco-pea boilers

Can you do the calculations yourself?

Self-calculation of the required power of the furnace is not a complicated task, it is enough to know the necessary data. It is worth doing it accurately, because the result obtained will allow you to choose the right boiler. Incorrect selection of a furnace, whether too low power or oversized will result in certain consequences. Calculating the power on your own is relatively simple, but if in doubt, you can use the help of a professional.

Why is it necessary to calculate the boiler output?

The correct selection of boiler power is extremely important for several reasons. One of them is the guarantee of obtaining the optimal air temperature in a building. The furnace must have sufficient heating power to completely meet the heating demand. Correct calculations will also guarantee the efficiency of its work, while taking into account the economy. Oversizing, that is, choosing a furnace with too much power, will result in greater expenses associated with the purchase of heating fuel. In turn, a boiler with too low and mismatched power, will not meet the demand for heat, and consequently the house will not be reheated on cold days. That's why correct calculations are crucial, so how to choose a pellet stove or other type of fuel for the area of the house?

Efficient and ecological pellet boilers

How to calculate the power of the boiler?

Wanting to calculate the power of the boiler, it is necessary to know the relevant data. The key here will be the area you want to heat, that is, the size of the house in square meters and the height of the rooms calculated in meters.

The power is calculated based on the formula:

Area of the house (m2) X height of the rooms (m) X area ratio (W).

The area index is the value of the heat loss of our house. It is assumed to be:

  • 120 to 200 W/m2 - houses without thermal insulation, which were built before 1982;

  • 90 to 120 W/m2 - houses built in the 1980s and 1990s;

  • 60 to 90 W/m2 - houses built since the late 1990s, well insulated with modern windows;

  • 50 W/m2 - houses built to requirements since 2017.

The result obtained in Watts is converted to kW.

Buying a boiler with too low or too high a wattage does not make sense. Both options carry certain consequences. That's why it is so important to accurately perform the calculations. It is important to substitute accurate data, because it determines the result, on the basis of which power is selected. It is also worth remembering that an improperly selected stove can cause problems during its operation.

See Stalmark central heating boilers

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