Like a previous (now locked) thread I have just read, I, too, am being plagued by the noise of a neighbours heat pump. The unit is a very large one (it's running an indoor ducted unit). This unit makes so much noise (both low frequency hum from the compressor, and fan noise from the two fans) that it prevents me from getting to sleep. When I do eventually get to sleep and I wake up during the night (say for a toilet stop), then it can be a couple of hours before I get back to sleep again. I hear the unit running (during the day) when I'm in the dining room, kitchen, lounge and garage of my house too. I don't think this is OK. I have had the (Auckland) council do noise level readings (and the unit seems to be not as noisy when he's here), but the compliance officer won't come out at night when the unit is running at its loudest. He initially (about two months ago) manage to read a noise power level of 55db at 8:00PM. The owner has fitted some insulation around the compressor and the inside of the casing of the unit, but this has just made the sound deeper - not quieter. The owner was initially OK about moving the unit, but has since expressed his intention of not doing so.
Any advice on how to move forwards please?
Peter W