condensate knocking in the gutter annoys neighbours

[Marko_J]

Hi,

I would like to put some questions about a problem.

We live in a condominium (please find attached the photo). The drain pipes of our air conditioners are led into the gutter (which is made of tin). There is a bend (see the red circle in the photo) in the gutter at our lower neighbours 3 m below the binding points of our drain pipes (see the green circles in the photo) The problem is that our condensate water knocks quite loudly at the mentioned bend for some time and it annoys our lower neighbours. They want us to decrease this noise.

This knocking noise is quite intense in about 15-20 minutes after switching off our air-conditioners and it becomes gradually lowered and stops approximately in 40-50 minutes. The length of the lower drain pipe of us is longer than the upper one. The lower one is approximately 6 m long (from the inner unit to the gutter junction point). When the condensate drops from this longer pipe into the gutter, the sound seems to be more intense.

I wonder if anyone has ideas how to solve this problem. Leading the condensate into a sink etc. inside our flat is not possible due to the conditions of the condominium and our flat. Maybe should we pull the drain pipes a little out of the gutter? In this way the whole condensate would flow down on the inner wall of the gutter (maybe this is not the situation for now).

Or shall we put a kind of filter to the points of the drain pipes indicated by green circles in order to decrease the size of condensate drops? Or should we exchange the tin bend of the gutter for a plastic one, or cover the tin bend inside with silicone, or should we carry the drain pipe in parallel with the gutter (but separately from it) downwards to the ground?

Thank you in advance,
Marko