pp hk ching, do you ever think to use copper tube instead of plastic tube??
use copper tube will have less noise?
if in wall socket box, use metal box instead of plastic.
these will be another world!
I used copper tube and metal box inside the wall.
But I am not sure whether any problem for electricity leaking safety issue for outside use metal box.
I brought very nice shiny heavy metal boxes in ssp around 50hkd per pce.