How to choose a Boiler

How to choose a Boiler according to the thermal requirements

When choosing your boiler, you must take into account several factors: the surface of the rooms, the power of the heating system, the size and type of radiators.

Thermal demand calculation and radiator calculation
Thermal demand quick calculation formula
Central heating boiler calculation: what to keep in mind
Types of thermal boilers
Calculating radiators
Choose Thermostat
Thermal demand calculation and choice of radiators.

Thermal demand is the amount of energy needed for thermal comfort, regardless of the season and the outside temperature. The thermal requirement is calculated based on the losses suffered by the building. Heat is lost: through walls, floors, windows, doors, ceilings and ventilation systems.

The calculation of the thermal demand is made with the help of a methodology defined in the Regulations. Based on these calculations, regarding the surface, the insulation coefficient, the temperature differences between the construction elements and not only, some indices are established. Thus, it is established which thermal power plant and which types of radiators are the most suitable building.

All these calculations are performed when the Heating System Project is designed.

Thermal demand calculation formula

To apply the heat demand calculation formula, you need to know exactly the area and height of the rooms (their value in square meters), as well as the degree of thermal insulation of the house (value in Watts / cubic meter).

Calculation example, for a thermal power plant for 80 sqm:

Area x Height x Coefficient: 80 sqm x 2.6 sqm x 40 W / m3 = 8,320 W (8.32 kW or 7,155 kcal / h)

Consequently, the minimum power of the plant indicated in a house of 80 square meters is approx. 8 kW,.

Central heating calculation
In order to calculate the thermal demand of the house, it is recommended to call a Designer for the execution of a Thermal Installation Project, because in addition to the surface, height and thermal insulation, there are other criteria that need to be taken into account.

One of them is the number of radiators to be installed. The more there are, the more powerful a thermal power plant will be needed. Also, for a underfloor heating system, another calculation of the thermal demand will be performed.

The number of bathrooms, the number of people (occupants of the building), the kitchen area also influence the final choice.

What are the types of thermal boilers

Thermal power plants are generally classified according to the type of fuel used and are divided as follows:

Gas boilers which, in turn, are of 2 types: conventional or condensing. Conventional ones have a lower purchase price, but condensed ones have a higher long-term efficiency, because they recover the heat from the flue gases and have a lower consumption.
LPG boilers are only used in cases where there is no access to any other type of fuel, because the consumption of LPG is expensive.
Electric boilers are less popular due to the higher price of electricity. They have the advantage of producing thermal power equal to the electrical power consumed, and therefore you will be able to estimate monthly consumption more easily.
Wood-fired boilers are used where there is no possibility of connection to gas or electricity networks. It works semi-automatically.
Pellet boilers offer better temperature control than wood boilers and are considered less polluting. It works completely automatically

Choosing radiators and calculating them
The thermal demand of the house will be provided not only by the boiler, but also by the radiators installed: the boiler is the heat generator, and the radiators give off the heat produced by the boiler. The radiators are of several types:

Aluminum radiators have the advantages of the affordable price, the modern look, the fact that they are light and that they heat up quickly. At the same time, they cool down quite quickly, deform and oxidize more easily.
Panel-type steel radiators have low purchase costs and a wide range of sizes, withstand high temperatures, but also have a shorter lifespan compared to aluminum ones. The aluminum face has superior mechanical strength.
Cast iron radiators stay warm for longer periods, although they are harder to heat (they have higher thermal inertia). They have a longer lifespan, but are even more expensive to purchase and involve additional maintenance costs.
Towel radiators are those used in bathrooms, made of steel or aluminum.
Decorative (or design) radiators are used in public spaces, living rooms or hallways and are also made of steel or aluminum.
To determine the efficiency of radiators, you need to consider both the heat they provide and their durability. The most important factors are:

the radiant surface it covers depending on the number of elements, length and width;
the coefficient of tr

When choosing your boiler, you must take into account several factors: the surface of the rooms, the power of the heating system, the size and type of radiators.

Necessary thermal calculation and radiator calculation
Thermally necessary quick calculation formula
Central heating power calculation: why keep in mind
Types of thermal power plants
Calculating radiators
Choose Thermostat
Necessary thermal calculation and choice of radiators
Thermal demand is the amount of energy needed for thermal comfort, regardless of the season and the outside temperature. The thermal requirement is calculated based on the losses suffered by the building. Heat is lost: through walls, floors, windows, doors, ceilings and ventilation systems.

All these calculations are performed when the Heating System Project is designed.

Thermally required calculation formula
To apply the heat demand calculation formula, you need to know exactly the area and height of the rooms (their value in square meters), as well as the degree of thermal insulation of the house (value in Watts / cubic meter).

Calculation example, for a thermal power plant for 80 sqm:

Area x Height x Coefficient: 80 sqm x 2.6 sqm x 40 W / m3 = 8,320 W (8.32 kW or 7,155 kcal / h)

Consequently, the minimum power of the plant indicated in a house of 80 square meters is approx. 8 kW,.

The number of bathrooms, the number of people (occupants of the building), the kitchen area also influence the final choice.

What are the types of thermal power plants
Thermal power plants are generally classified according to the type of fuel used and are divided as follows:

Gas boilers which, in turn, are of 2 types: conventional or condensing. Conventional ones have a lower purchase price, but condensed ones have a higher long-term efficiency, because they recover the heat from the flue gases and have a lower consumption.
LPG boilers are only used in cases where there is no access to any other type of fuel, because the consumption of LPG is expensive.
Power plants are less popular due to the higher price of electricity. They have the advantage of producing thermal power equal to the electrical power consumed, and therefore you will be able to estimate monthly consumption more easily.
Wood-fired boilers are used where there is no possibility of connection to gas or electricity networks. It works semi-automatically.
Pellet boilers offer better temperature control than wood boilers and are considered less polluting. It works completely automatically

Choosing radiators and calculating them

The thermal demand of the house will be provided not only by the boiler, but also by the radiators installed: the boiler is the heat generator, and the radiators give off the heat produced by the boiler. The radiators are of several types:

To determine the efficiency of radiators, you need to consider both the heat they provide and their durability. The most important factors are:

the radiant surface it covers depending on the number of elements, length and width;
heat transfer coefficient of the material from which the radiator is made (aluminum, steel, cast iron);
the temperature of the heating medium, the period required for heating and the volume of the space in which it is installed.