ScottG wrote:
Some of the newer bypass pumps aren't too bad.
Most of the noise comes from the plumbing vibrating against walls and what not.
If you can isolate the water lines where ever they touch anything (pipe insulation works great) you can reduce noise dramatically.
There are also "Quiet Kits" that add more flexible lines to the input and output and allow the pump to vibrate without transferring that to the harder pipes and anything they touch.
Some even put foam or rubber pads under the pump.
x2. find the quitest pump you can, and do the above to further reduce noise. Most pumps now list a db level. FWIW a mid level pump isolated well can easily be quiter than a very quite pump mounted to a board with hard connection lines running against hard material.