They're as noisy as an AC. So here in Arizona no one cares. But in Belgium this was an issue as they run more in winter and in winter sound travels further.
Just installed heat pump systems (daikin) this december.
The exterior unit is basically silent even when there was a cold snap (below freezing but not northern alaska cold).
I suspect an interior air source heat pump hot water heater, being smaller, will be noisier, and likely less efficient.
I'd love to switch my 240v/30a water heater to use a 120v/20a service, but will wait a bit longer for the technology to mature. Ideally it'd have the heat collection part outside.
Uhmm...I see a problem for countries where you have wall to wall connected urban environments...If all 60 connected houses on a street, install external heat pumps, it will add up.
Turns out cities are loud! In NYC, at least, heat pumps are far more quiet than the endless window unit A/C's, or larger traditional A/C's, in my experience.
Outdoor noise is less of an issue in the winter in big cities because windows are closed.
Also, when talking about noise it's important to talk about frequency. If they produce low frequency noise, that can be far more irritating. Shutting the windows won't help much
Depends on the installer. A lot of noise results from units that are not properly mounted or mounted at a slight engine. The fan then starts getting more noisy and wears out earlier. There are other problems to not installing units properly.
