[patrickk]

Modern air or ground source heat pumps tend to be quiet, even silent, at least according to some deep dives down the Youtube rabbit hole on passive houses. Check out the "Moonstone house" on Youtube for example.

https://youtu.be/sSE8PurhfQs

[dx034]

My neighbour has a air heat pump for a ~200m2 house with good insulation, but not a passive house. It's at the edge of his property so I regularly pass it. I'd say you need to be less than a meter away to hear it at all, and even then it sounds like a fan. There's absolutely no vibration or so.

However, the house is new, let's see how it the unit sounds in 5-10 years.

[tpxl]

We have a heat pump from ~2008 about a meter away from the outer wall of the house and I don't recall ever hearing it from the inside. You'll hear it from a few meters on the outside, but it has never been a problem. It's able to heat a ~250m2 house in -10°C weather.

That being said, do yourself a favor and do not get a heat pump connected to 'the cloud'. Our heat pump can't be fully controlled locally (some functionality is web only) otherwise I'd put it offline. They unnecessarily performed repairs on the heat pump to the tune of 500€ because their servers had issues.