Actually, we wanted to place these in front of the guest bathroom window facing the street.
The bathroom is directly adjacent to the neighboring house, isn't it?
In Bavaria, such a thing would at least be inadmissible if the neighbor does not want it:
A neighbor must generally remove an air heat pump that he has installed at a distance of less than three meters from the neighboring property. This was decided by the Higher Regional Court of Nuremberg with a judgment dated January 30, 2017. The provisions of building regulations also have their protective effect in neighborly relations and lead to a civil law claim for removal (case no.: 14 U 2612/15).
The defendant operates a heat pump on her property that is two meters away from the plaintiffs' neighboring property. The plaintiffs demanded that the defendant remove the heat pump because it caused significant noise pollution. The Nuremberg-Fürth Regional Court initially affirmed a claim for removal. The defendant filed an appeal against this. The Higher Regional Court confirmed the Regional Court's decision and also affirmed the plaintiffs' claim for removal of the heat pump. The defendant did not maintain the legally required clearance distance, which is at least three meters. DThe heat pump is considered another installation within the meaning of Art. 6 para. 1 sentence 2 of the Bavarian Building Code, since it has an effect similar to that of a building....According to the Higher Regional Court, it does not depend on the installation's size but on the emissions it generally causes. Regardless of the amount of noise emitted by the heat pump, these are at least suitable to endanger neighborly peace. This is precisely what the regulations on clearance distances are meant to protect.
For the situation in Baden-Württemberg, search for "Civil law claims for removal against air heat pumps Dr. Werner Nickl, Eislingen," where this is discussed in detail.