Heat pump directly next to the bedroom window

I find both solutions bad. Why not street-side or similar? A site plan would be helpful.

Good morning, if the pump reaches its full volume at very cold temperatures at night, you will be glad if it is far away from the bedroom! If it is possible at the guest toilet with distance to the neighbor, then install it there! It is important that the sound travels and is sometimes broken so that few decibels reach the neighbor. I once had trouble with mine, 2 winters long, measured twice. It was within the tolerance range, he got used to it!

Instead of jeopardizing it with the neighbor, I would rather take the risk next to my own bedroom. I even consider the latter to be a lower risk. It probably won’t be audible in the house/bedroom.

I would also not be so careless as to place the outdoor unit in front of the bedroom. The DB values specified in the datasheet can sometimes be significantly exceeded during extreme weather conditions. There are different kinds of outdoor units. In our development area, there are among others many Buderus, which are sometimes extremely unpleasantly humming loud. Fortunately far away from us. We have a brine-water heat pump with drilling ;-) because precisely for that reason we did not want to have an outdoor unit (appearance, noise, efficiency). Of course many have an air-water heat pump with an outdoor unit and that also works in practice. But you cannot change it afterwards (or only with great effort) if it is not good for you. I would look for a location further away that possibly can still be enclosed (replanted)?

We faced a similar question. The architect wanted to position it near the bedroom behind a recess to make it visually disappear. I care a lot about appearance, but I would never ever have wanted that thing near the bedroom because of that! Who knows how it would have behaved with sound reflection in the actual situation.

No one can guarantee that you won’t hear it. I, for example, am very sensitive to noise and hear the slightest sounds, while my husband hears nothing at all. When we walk through the new development area in the evenings during winter, he hears nothing, while I congratulate myself at every second house for having turned away from it right in front of our window. And on top of that, depending on how sensitive you are, if you already know that the thing is there and it is actually not the preferred or optimal location, then you tend to listen especially carefully….

Thank you for the numerous opinions, that already helps a lot. Here are some plans to illustrate, the two potential heat pump locations are marked in blue. The distance to the neighbor's building is about 13m (I had previously miscalculated), the distance to the property boundary is almost 6m. Of course, I do not want to disturb the neighbors with noise, but I believe that due to the distance, nothing will be heard, especially since there will also be walls there that would partially block the sound.

The heat pump line has already been routed from the basement to the bedroom outside, this area has also been backfilled. Other locations are therefore rather difficult, also due to the very steep terrain in general. The question now is whether the line will be extended and the heat pump placed further up or whether it will remain where the line currently ends (between the bedroom and the children's room). When looking at the plans, please note that our living floor including terrace and garden is on the upper floor.

In winter, the windows are usually kept closed, so I see absolutely no problem with 13m and would definitely not cause myself trouble out of misguided consideration.