It seems placement will not matter, If you have room inside I would put it there as my setup has. This helps keep the curiosity level down somewhat and less explaining to do
if someone should stumble upon your room
Well I mean unless its a filter made to have air blown through it, if should be before your inline fan. I have mine in my tent and the fan sucks air through the filter, then the cooltube and then exhausts into the room. There is no smell for me and I always heard that fan and filters are more efficient sucking not blowing.