A separator which can be used for separating water from an air/water mixture in an aircraft where the air is to be supplied to electronics equipment comprises a chamber containing a generally tangential inlet tube through which a mixture is supplied to a curved side wall section of the chamber to separate water from the air by centrifugal action. The efficiency of the unit is improved either by moving the filter unit away from the centre of the chamber or by providing a guide plate between the filter unit and the curved side wall on which the water coalesces. In this latter case, the filter unit can also be offset from the centre of the chamber to give even greater improvement and efficiency.
