what power for a house of 120 m2?

A heat pumpit is a environmentally friendly and economical heating, thanks to its often incomparable performance. The operation is simple: the pump “captures” the heat in the air or in a water point and then restores it in a home. But to function and provide the expected comfort, it must have the right power. explanation.

> Read also: Which heat pump capacity for a house of 100 m2?

Calculating the ideal power of the heat pump

To find out what power is needed to heat, with a heat pump, a house of 120 m2 (and there producing hot water if applicable), four factors must be taken into account: the volume to be heated, the basic outdoor temperature, the ambient temperature and the building coefficient.

The volume to be heated

The volume to be heated is the first criterion to take into account when calculating the capacity of your heat pump. In reality, we not only heat the m2 on the floor, but the volume from the floor to the ceiling † For a house of 120 m2 and a ceiling height of 2.5 meters, the volume is therefore 300 m3 (120 x 2.5).

> Read also: Which settings for your heat pump?

The basic outside temperature

more the base outside temperature of the region where your home is located will be the more your heat pump has to “effort”. This temperature is determined by the state according to 9 zones (from A to I), which are themselves subdivided into altitude intervals. Your installer can provide you with this information.

heat pump installer

room temperature

You want to bring this ambient temperature into your home. Mostly, we recommend aiming for 19°C at home, although many think their comfort will be greater at 21°C. Of course, this temperature influences the energy consumption of the heat pump

The construction coefficient

With this coefficient you can:estimate heat loss from your home related to the materials used for the construction and the quality of the thermal insulation† To find out, you should consult the RT (thermal control) standard that your home complies with.

The calculation formula for 120 m2

To find out the ideal power of your heat pump for a house of 120 m2, you must apply the following formula:

Power expressed in watts = volume to be heated X construction coefficient

X (desired room temperature – basic outdoor temperature)

For our example of a house of 120 m2, considering an average construction coefficient of 1.2, a desired temperature of 21°C and a base outside temperature of -5°C:

300 X 1.2 X (21 – (-5)) = 8640 watts

> Read also: Where to install a heat pump?

Reasons to correctly calculate the capacity of your heat pump

Correct calculation of the heat pump capacity is important. In reality, if it is below par, you will not be able to reach the desired temperatures† In other words, you will get cold! In addition, your heat pump is continuously running at full speed, which means that excessive power is consumed.

heat pump-for-home

On the other hand, if your heat pump is too large, it will wear out faster due to the many stops and restarts it will undergo. Maintenance costs will be higher than expected, and it is lifetime could be reduced.