We have the flow and return pipes from our Daikin ASHP monobloc running up the wall on the side of our bedroom window without any problem. I don’t know if any audible noises emanate from those pipes, but if it does, I suspect that the insulation must be reducing it anyway. Normal practice is to fit flexible pipework to the return and flow connections on the heat pump and this usually isolates much of the vibration being transmitted and transferred into those rigid pipes up the wall.

NB. We live in a very noisy ambient sound level due to traffic, (roads, railway and aircraft) and cannot hear anything from our heatpump unless we are within a metre of the housing. Regards, Toodles.

Post script: We normally sleep with the double glazed window open and it has not caused any loss of sleep or any irritation due to the heat pump running. Please see photo, that horizontal run on the right is to the airing cupboard in our bedroom and that is the window I mention.

Regards, Toodles

@toodles Thanks!  In my case, the pipes would run where your soil pipe does and into the loft (our soffits are probably 40-50cm wide)  Our bedroom window was originally a door so it's pretty much a floor to ceiling window so looking at your photo, it would probably run to about half way between your bedroom and kitchen windows.  Good point about the flexible coupling.

Post Post Script! This new photo may be a little clearer @andrewj

Regards, Toodles.

Cheers - it certainly seems like it ought not to be an issue so that's good.

My cylinder, buffer tank and the hot water circulating pump are in a room underneath my bedroom (which has become noticeably warmer). There was audible noise from circulating water when the pump was at maximum speed (as left by the installers) and I reduced it to medium speed without reduced noise and no adverse effect on circulation. Recently, after monitoring temperatures in / out of the buffer tank I've reduced the pump to minimum speed which gives slightly better heat transfer, minimal flow noise and the heat still reaches the extremities. I haven't found any way to control the flow rate of the pump built into my Arotherm+ but the primary circuit uses 28mm pipes whereas the pipework to the radiators is smaller. Bigger pipes reduce the flow velocity (and hence potential to make noise) in proportion to the diameter squared.

@johnr We currently have an oversized (seriously oversized) pump in the airing cupboard by the bedroom door at the moment and I don't hear that and I'm not bothered about the 15mm pipe work as obviously that's already in the bedroom and not an issue.  It sounds to me like it's not going to be an issue with the 28mm pipes.