Hi all,
I understand the water seperators also do a fairly good job of cleaning the air as passes through, it's the main cause of problems with aircon temperature control on Boeings.
The seperators get dirty, generate a differential pressure each side in the duct, and the aircon system sees it as an ice build-up, and programs an increase in airtemp to get rid of it.
Usually have to go to manual mode to get control back, but have to be really careful not to freeze the seperators, because there is most always some ice in there!
Cheers