Properly install your heat pump outdoor unit - northern exposure ☠️, headwind 💀?

You are looking for information on the air-to-water heat pump, or air-to-air heat pump, and you are probably wondering about the ideal location of the outdoor unit that will capture the heat from the outside air.

Indeed, it is the central element of the installation:

  • It is him who will ensure your energy savings by capturing the free calories in the air.
  • It is the one that can eventually cause problems because of aesthetics.
  • This is the one that can get you into an unfortunate lawsuit because of the noise that it creates, either because the machine is of poor quality, or because one forgot to calculate the distances to the neighbors or to take into account the reverberation.

So you might as well think carefully about choosing the perfect location.

But this location depends on many factors, and will be different for each situation. This is what we will see in the rest of this article.

Stay to the end to pick up two quick tips to help you improve your outdoor unit installation.

The heat pump's outdoor unit AND neighborhood constraints

Neighborhoods are often the primary cause of forced abandonment of a heat pump heating project, sometimes resulting in years of litigation that takes a toll on you both physically and mentally. We've been there, we've seen it, and we can tell you that it's in your best interest to plan ahead to avoid it.

Distance to be respected from property lines

Although some countries recommend distances from neighbouring property lines for the installation of a heat pump, e.g. 3 metres in Germany and 20 metres in France and Switzerland, the question of distance is not really central as long as the noise generated remains within the norm.

Instead, focus on the noise generated that reaches the first living room window of your closest neighbors. The distance should be varied as much as possible to reduce the noise.

Noise level in relation to neighbors when installing an outdoor unit for a heat pump

In France, it is mandatory to respect deviations from the ambient noise. During the day, it is forbidden to generate more than 5dBA above the ambient noise in your residential area, and at night this drops to 3dBA. (article R. 1336-7 of the public health code)

In Switzerland, the noise form must be complied with in order to obtain a building permit. This is a guarantee that the heat pump complies with the standard. 55dBA must not be exceeded during the day and 45dBA at night. You can simulate the result via this page

In other countries, the regulations do not provide for this, but in order to avoid problems it is recommended to place oneself about 20 meters away if possible.

Heat pump outdoor unit AND aesthetic / practical considerations

Whether you are the owner of your own home, or in a condominium, the aesthetic criterion is often at the top of the list of concerns, for you as well as for your neighbors.

Preservation of the visual environment of your garden and your house

Indeed, no one wants an intruder to disturb the harmony of their little corner of paradise. That's why we're sharing with you 3 tips to make sure everything goes smoothly:

  1. You can hide the outdoor unit with plants, under two conditions: a) Do not obstruct the air flow in front of the unit. b) Leave room for maintenance
  2. You can also use what is called air conditioning covers or heat pump covers. These consist of wooden lattices or wooden shelters that cover the outdoor unit of the heat pump and thus hide it from view. You can choose the material according to the facade of your home. A cottage will more easily opt for wood, while a white townhouse will rather go for a white metal look.
  3. Place the outdoor unit in the most inconspicuous place possible while keeping the right distance from the neighbors to avoid acoustic disturbance.

Avoiding traffic areas

  1. It is advisable to place the outdoor unit away from any area frequented by pedestrians or family members. This will allow:
  • To avoid an accidental impact, from a playing child, a pedestrian, or a car, that could result in a lawsuit. You never know.
  • Avoid vibrations that could damage the heat pump

2. In addition, it is necessary to think about pouring a concrete slab, or failing that, to install the heat pump on big foot which are large anti-vibration blocks, which will protect your outdoor unit from flooding or other shocks.

3. While avoiding frequent walkways next to the machine, access must still be easy, especially for the technician who will be passing by to perform maintenance. Also the space around the machine is important to ensure good air circulation and optimal operation. As such, we have written an article that talks about the distance between the heat pump's outdoor unit and the wall of your homeIf your machine is placed on the front of the building.

Weather and orientation considerations for the outdoor unit of the Air to Water or Air to Air heat pump

As the outdoor unit is continuously exposed to the sometimes harsh conditions of Nature, there are several points to pay attention to in order to maximize the return on your investment, or your energy savings.

Protection of the outdoor unit against the weather (snow or frost)

Depending on your country or region, the climate can vary greatly. It is important to protect the outdoor unit from snow and frost, mainly for 5 reasons:

  1. You preserve its performance by preventing a layer of ice from forming on the evaporator, preventing normal operation
  2. You extend the life of the machine because it is less exposed to corrosion and wear of parts due to harsh conditions.
  3. You avoid too many breakdowns, such as a fan blockage due to snow, or any other breakdown due to poor condensate drainage
  4. It's easier to maintain, and less likely that you'll have to change expensive parts in the long run
  5. It's more secure: frozen condensation water can turn your driveway into an ice rink, ice can fall from the roof onto the machine and break it or injure someone.

For all these reasons, it is advisable to install the outdoor unit a little higher than the ground to avoid snow or water accumulation around it and to have a simpler condensate evacuation no matter what happens.

It would also be excellent, but a little expensive, to install the heat pump under a shelter, while maintaining good air circulation. We often see wooden mini-shelters, with a small roof.

Finally, especially in cold weather, check the condition of the outdoor unit when you pass by and remove snow if necessary, defrost by hand if no automatic defrosting, or ineffective.

Install the outdoor unit away from the prevailing winds of the region

In many parts of Europe, the prevailing winds are from the west-southwest, but in some areas it is completely different. Whatever the wind in your area, a little research and observation will help you to know the direction of the wind, and thus find the most protected location for your outdoor unit.

This is important for several reasons:

  1. Optimize performance, as strong winds disrupt the airflow and can reduce the efficiency of the heat pump because they decrease the heat exchange capacity.
  2. High winds can wear out machine components faster and increase your maintenance expenses.
  3. Strong winds may involve more vibration noise in the you will reduce the nuisance

You can use natural obstacles to protect your machine from the wind, hedges, trees, walls, etc.

Finally it is possible to install a wind screen, if no other solution, to ensure a good operation of the heat pump and good energy performance despite a strong wind.

The ideal orientation to optimize the defrost cycle

Exposure of your heat pump to the north? A good idea? The answer is no. Unless you have no choice. It is much better to orient the outdoor unit to the south or west.

The idea is to take advantage of maximum sunlight to promote natural defrosting of the exchanger if it has frozen.

In addition, you should avoid placing the heat pump's outdoor unit under a roof or in any area with a lot of shade. In fact, this is a recipe for having ice on the exchanger too often and limiting performance and therefore increasing electricity consumption.

Of course, all modern heat pumps are equipped with a defrosting cycle, either by cycle inversion or hot gas bypass. But it is preferable to do everything possible to avoid too frequent freezing due to a poorly chosen location.

If you have chosen the wrong location and realize it after the first season, it is never too late to change the orientation. But it may involve some work and expense.

Two little tips to improve the installation of the outdoor unit

The semi-open room

A very good advice is to first consider a semi-open space to install the outdoor unit. This will allow you to simply protect the heat pump from the wind. This room could also be a carport or an awning or anything else useful for you. It will however be necessary to ensure the circulation of air, even if it means installing grills in this room for its ventilation.

Bottom tracer or heating cord if the heat pump is exposed to the North

If you have not found any other solution than to install the heat pump to the north, then you are exposed to frost, to the decrease of exchanges and performances in cold period.

Therefore you can install a tracer at the bottom of the condensate pan of your outdoor unit. This is an electrical resistance that heats the bottom of the pan and thus accelerates defrosting. The heat pump then resumes normal operation more quickly, when it is cold and heating is really needed.

Several manufacturers offer these tracers, also called heating cord. Delta Dore, or Raychem...your installer will find them at his favorite wholesaler. They cost between 50 and 200€ each.


After all this advice, I told myself that those in a hurry would never have time to read everything, so here is a summary in table form of the advice for WELL installing your heat pump outdoor unit:

1. Respect the distances with the neighborsTake into account local regulations regarding distances and noise to avoid problems with neighbors.
2. Consider the aestheticsUse plants, air conditioning covers or a discreet location to hide the outdoor unit and preserve the harmony of your environment.
3. Avoid high traffic areasInstall the outdoor unit away from busy areas to avoid accidents and vibrations.
4. Provide easy accessEnsure that the outdoor unit is easily accessible for maintenance and service.
5. Protection against the weatherInstall the outdoor unit elevated and/or under a shelter to protect it from snow, frost and other weather conditions.
6. Protect yourself from prevailing windsConsider the prevailing winds in your area and use natural barriers or install a wind screen to protect the outdoor unit.
7. Choose an optimal orientationOrient the outdoor unit to the south or west to take advantage of sunlight and facilitate defrosting. Avoid areas of excessive shade.
8. Tip: the semi-open roomConsider a semi-open room to protect the outdoor unit from wind while ensuring good air circulation.
9. Tip: bottom tracerInstall a pan tracer or heater cord to speed up defrosting of the outdoor unit, especially if it is exposed to the north.