Heat pump: how to avoid or reduce noise pollution?

Whether it's a Daikin, Atlantic, Castorama or Mitsubishi heat pump, are you hesitant to buy a heat pump because you're afraid of the noise pollution it could cause?
Your neighbor has installed a heat pump, its noise bothers you, and you wonder what you can do?
We explain to you:

Why does the heat pump make noise and how many decibels does it generate?

What are the obligations and the decibel thresholds not to be exceeded according to the law, whether it concerns noise pollution caused by your heat pump or those of your neighbour?

What should you do if the noise from your neighbour's heat pump bothers you?

How to reduce the noise of a heat pump?

  • Choose the right model
  • Find the right location
  • Take care of the installation to limit noise
  • Install a noise barrier
  • Acoustically isolate
  • Use a soundproof box
  • Ensure proper maintenance to limit noise pollution

Follow the guide!

Why does the heat pump make noise and how many decibels does it generate?

Heat pumps produce noise due to their design: the main culprits of this noise pollution are the fan and the compressor located in the outdoor unit of the heat pump.
Thus, among the different heat pump models, be aware that geothermal heat pumps (which fetch calories from the ground) or hygrothermal (which fetch heat from groundwater) are much quieter than air/water or than air-to-air heat pumps.
In addition, when the device activates the defrost function, the noise increases at this time.

heat pump soundproof box

But fortunately the manufacturers have greatly improved the sound levels in recent years, going from 75dB (the equivalent of the noise of a vacuum cleaner) to now 40dB for the quietest pacs on the market today (therefore less noisy than a washing machine). -recent dishes). The gain between the two is enormous and we can only rejoice.
Other factors can influence the sound level of a heat pump. First of all, its location, because at a distance of 1 to 5 meters, the noise pollution is reduced even further.
It is therefore important not to place the device too close to the neighborhood or too close to your windows.
Also be careful not to create a sounding board, sometimes we do worse than better. Finally, a poorly maintained heat pump can also generate additional noise pollution .

Noise pollution caused by your heat pump or that of the neighbor: what are the obligations and the decibel thresholds not to be exceeded according to the law?

According to the Health Code: no particular noise must, by its duration, its repetition or its intensity, affect the tranquility of the neighborhood or the health of man.
In terms of noise pollution generated by a heat pump, the decree of August 31, 2006 on neighborhood noise applies (articles R.1334-33 and R.1337-7 of this code).
This decree does not set a maximum decibel threshold not to be exceeded in absolute terms, but sets a maximum noise emergence to be attributed to the device. This means that the difference between the ambient noise when the device is not working and the noise when the device is working is taken into account. Emergence is therefore a notion relating to the environment in which the heat pump is placed. Basically, its acceptable decibel level is lower if it is in a quiet environment than if it is installed near a national road where traffic is already generating noise.
The decree stipulates that the difference between ambient noise and residual noise (“emergence”) must not exceed 5 decibels during the day (from 7 a.m. to 10 p.m.) and 3 dB(A) at night (from 10 p.m. to 7 a.m.).
If you are the owner of a heat pump which is proven to exceed these noise thresholds, you expose yourself to the payment of a fine of €450, or even the confiscation of the heat pump in question.
Note that in new housing, the legislation is more restrictive. Manufacturers are indeed now subject to the NRA 2000 regulations (orders of June 30, 1999 – Official Journal of July 17, 1999, p. 10658 et seq. and p. 10660) which imposes absolute thresholds this time in terms of noise in the accommodations. It is not allowed to exceed 35dB in living rooms for noise generated by heat pumps.
In any case, since the decree of July 28, 2020, maintenance of the heat pump is compulsory every 2 years for appliances with a power between 4 and 70 kW, and every year for appliances with a higher power. at 70kW.

Now that we've laid the framework, let's get to the heart of the matter:

How to reduce the noise of a heat pump?

Choose the quietest heat pump model

If you have the option of installing a geothermal or hygrothermal heat pump, these are the quietest models.
If you cannot carry out this type of installation, then in this case compare the sound levels indicated on the labels of the heat pumps and keep in mind that a difference of 3dB between two devices is significant.
Finally, it is important to correctly size the appliance according to your heating and hot water needs. A heat pump with a power that is too high or too low in relation to your needs can in fact generate unnecessary excess noise pollution by multiplying untimely stops/starts or by operating continuously.


Find the right location to reduce heat pump noise

This step is decisive for minimizing noise pollution and limiting the propagation of noise .
So here are some tips to follow:

  • The sound attenuates quite quickly in the air, so move the outdoor heat pump unit as far away as possible from your windows, the rooms you live in the most (living room, bedroom) and neighbors
  • Orient the device so that the sound does not travel in a straight line towards your neighbours. Simply rotate the device 90° to redirect the sound waves farther and greatly improve the acoustic effect
  • Avoid placing the device in a corner, hollow or enclosed area such as an interior courtyard which would act as a sounding board and accentuate the noise

The Environment and Energy Management Agency (ADEME) has published a guide containing valuable recommendations on the best way to install your heat pump so as to minimize noise pollution . Here's what comes out of it:

Pay attention to the installation of the heat pump to reduce noise pollution

  • Do not glue the heat pump to the wall to avoid the propagation of vibrations. A spacing of 40 to 50cm makes it possible to limit the reverberation of noise on the wall.
  • Provide a stable and straight seat under the heat pump, but be careful, the concrete base is a false good idea because it increases the reverberation of noise. It is preferable to place the heat pump on a rubber anti-vibration base (anti-vibration pad) which will reduce vibrations

heat pump noise reduction system

reduce noise pac

Install a noise barrier near the heat pump

If you have no choice for the location of your heat pump and it is found near your windows or those of your neighborhood, you can consider the installation of a noise barrier in order to stop the spread of noise pollution. But the noise barrier must be placed next to the heat pump for more efficiency.

noise barrier heat pump

Install sound insulation to reduce noise pollution

The installation of insulating materials near the heat pump is also interesting because these materials make it possible to reduce the reverberation of sound waves (foam, glass wool, etc.), and prevent the propagation of vibrations (felt, rubber, cork) which are sources of noise.
Finally, you can also use natural acoustic insulation solutions such as a hedge, an embankment, or a wall to divert the noise waves in another direction.

noise barrier

Place an anti-noise box on the heat pump which allows the air to circulate around the device

All the solutions seen above are useful but can be complicated to set up and expensive. The most popular solution is therefore usually the installation of insulating casing around the heat pump to reduce its noise emissions.
But beware ! The heat pump needs air circulation all around it at all times to work well. It is therefore advisable to avoid buying or manufacturing an airtight soundproof box which would insulate the noise acoustically but which would harm the performance of the heat pump.
Prefer a quality formwork equipped with large louvers, specially designed for heat pumps by a specialist.
This is the case with Decoclim heat pump covers . These heat pump boxes reduce noise pollution without degrading performance. Their material, their assembly and the specific orientation of their louvers insulate motor and fan noise, redirect sound waves away from the ears, and thus reduce heat pump noise by 10 to 30%. A really big gain when it comes to decibels.
It is also an anti-noise solution that is easy and quick to install, and which also brings an aesthetic gain because the box is decorative, it dresses the heat pump and makes you forget about it.
Naturally, these insulating formwork can be removed just as simply, like a painting, to allow maintenance of the device.

noise canceling box pac

Ensure regular maintenance of the heat pump

It is important to carry out regular maintenance of the heat pump, every year or every two years at least depending on its power, to prevent leaves or twigs from entering the device and interfering with the movement of the fan or the operation of the motor, which would have the effect of generating additional noise which it is desirable to avoid. It is also necessary to clean the filters regularly to prevent them from clogging.

Your neighbor has installed a heat pump whose noise bothers you: what to do?

Dialogue is always preferred first.
For a quick effect, without incurring major work, you can already ask him if he would agree to install shuttering formwork on his heat pump to reduce noise.
Depending on the result, you can then consider with him the other insulating solutions described in this article and see, depending on the configuration of the premises, what it would be possible to put in place.
But if your neighbor does not show goodwill and turns a deaf ear, do not hesitate to check whether he has complied with the legislation regarding the installation of outdoor air conditioners and heat pumps . Otherwise, he may be forced to remove the device and be fined. This perspective alone is sometimes enough to find the path to dialogue…

Learn more about the Decoclim heat pump cover
cap cover