A heat pump is a environmentally friendly and economical heater, thanks to its often incomparable performance. Its operation is simple: the pump “captures” the heat in the air or at a point of water and then returns it to a house. But in order to function and provide the expected comfort, it must have the proper power. Explanations.
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The calculation of the ideal power of the heat pump
To find out what power is needed heat, with heat pump, detached house 120 m2 (and produce hot water there if necessary), four factors must be taken into account: the volume to be heated, the basal outside temperature, the ambient temperature and the building factor.
The volume to be heated
The volume to be heated is the first criterion to consider when calculating the heat pump power. In fact, we heat not only the m2 on the ground, but the volume from floor to ceiling ! Thus, for a house of 120 m2 and a ceiling height of 2.5 meters, the volume is 300 m3 (120 x 2.5).
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The basic outside temperature
More the outside base temperature of the area the lower your home will be, the more “effort” the heat pump has to make. This temperature is set by the State according to 9 zones (from A to I), which are divided into altitude intervals. Your installer will be able to provide you with this information.
This ambient temperature is what you want to get at home. Most of the time, we recommend aiming at 19 ° C at home, although many believe that their comfort will be greater at 21 ° C. Of course, this temperature has an impact on the energy consumption of the heat pump.
The building factor
This rate will allow you tocalculate the heat loss from your home related to the materials used for its construction and the quality of its thermal insulation. To find out, you need to refer to the RT (thermal regulation) standard that your home complies with.
The calculation type for 120 m2
To find out the ideal heat pump power for a 120 m2 house, you need to apply the following formula:
Power expressed in watts = volume to be heated X build factor
X (desired room temperature – basic outside temperature)
Consider, for example, a 120 m2 house, taking into account an average building factor of 1.2, a desired temperature of 21 ° C and an outside base temperature of -5 ° C:
300 X 1.2 X (21 – (-5)) = 8640 watts
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Reasons to calculate the power of the heat pump correctly
Properly calculating the heat pump power is important. In fact, if it is smaller, you will not be able to reach the desired temperatures. That is, you will catch a cold! In addition, the heat pump will run continuously at full speed, resulting in overconsumption of electricity.
If, on the other hand, the heat pump is oversized, then it will wear out faster due to the many stops and restarts it will suffer. Maintenance costs will be higher than expected and its service life could be reduced.