I have a customer on a local industrial estate with a very smelly Gents toilet.
Ladies is next door & both toilets have vents in the ceiling tiles connected to ducting and then to a large slow running fan which exhausts outside.
Ladies smells fine, Gents really stinks. Checked for leaks around the soil pipe etc, cleaned out the ducting. Airflow seems the same from both vents, but no way of testing it.
Is there any kind of air treatment equipment that might help? Would an Ioniser make any difference?