What do you need to know when choosing a boiler for your home? Calculation of Kw a boiler must have per sqm.
Choosing a boiler for your home often brings many questions to those who need to install a complete product that will not fail over time. The first of these questions, therefore, is: what should I do to find the boiler that best meets my needs? In this post we will list some key points for making an informed choice.
Index:
- Calculation of the Kw output of a boiler
- Calculation of calorific value
- Positioning the boiler
- Calculation of the cubic metres of the home
- Boiler for a 90sqm flat
- Boiler for a 60sqm flat
- Boiler for a 120sqm flat
Calculation of the Kw output of a boiler
A particularly important aspect is the calculation of the Kw output, which is required for an efficient system suitable for your flat. Calculating the Kw (kilowatt) power is not difficult and is obtained by multiplying the cubic metres of your flat by the heating power. The result, rounded up, will indicate which Kw value you should use when choosing your boiler.
Calculation of calorific value
The calorific value is the amount of heat released by the boiler while it is in operation. It can be calculated from the energy class of your flat. The energy class of a flat indicates the impact the building has on its surroundings by calculating the efficiency of parts of the house such as fixtures, insulation, wall thickness, how many openings there are based in square metres, etc.
There are 10 energy classes of which the most efficient is A4 and the least efficient is G. The specific heat is a coefficient (ranging from 0.3 to 0.8) and is obtained from the energy class of the flat.
Positioning the boiler
The positioning of the boiler is often a particularly underestimated aspect, although can prove to be a very important factor. For example, if the hot water has to travel a considerable distance before reaching the taps or radiators, it will do more work.
Room-sealed boilers can be installed inside the flat, while open-flue boilers can only be installed outside for safety reasons. To date, it is advisable to opt for a room-sealed rather than an open flue boiler for safety reasons.
Calculation of the cubic metres of the home
Calculating the cubic metres of your flat is very simple (probably the simplest calculation among those listed in the article). All you have to do is calculate the square metres of the flat and multiply them by the overall height of the flat.
E.g.: If you have a 100sqm house with a height of 3 metres, the cubic metres of the house are 300.
Boiler for a 90sqm flat
To make this choice, one must start by calculating the cubic metres of the flat: flat square metres x flat height. Assuming a height of 3 metres, the calculation is soon ready – 90 x 3 = 270. The result should be multiplied by the specific heat of the flat. In a generic case, let us assume a house with minimal energy efficiency and therefore a specific heat coefficient of 0.8.
The result of the multiplication of cubic metres x specific heat makes 21.16, which therefore offers an excellent reference point for the minimum Kw of an efficient system. In this case, we recommend a 24Kw boiler.
Boiler for a 60sqm flat
The calculation to be carried out is the same as for choosing the boiler for a 90sqm flat. Calculation of the cubic metres of the flat: 60×3 = 180 (assuming the flat is 3 metres high). The result, as already mentioned, will have to be multiplied with the specific power of the flat, which we imagine to be 0.8 (the minimum).
This multiplication gives a value of 14.4, which indicates that a 24Kw boiler will also be sufficient in this case.
Boiler for a 120sqm flat
The calculation to be carried out is always the same. Calculation of flat cubic metres: 120×3 = 360 (assuming the flat is 3 metres high). The result should be multiplied with the specific power of the flat, which we imagine to be 0.8 (the minimum).
This gives a value of 28.8 and in this case it is therefore advisable to purchase a boiler of at least 30Kw.
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