Abstract: A refrigeration apparatus contains an oil sump having an interior portion. A housing is located, at least in part, within the oil sump interior. The housing has at least one inlet and at least one outlet. The inlet allows a vent gas stream to enter the housing and the outlet allows a vent gas stream to exit the housing. The inlet may be an aperture extending circumferentially around the housing about one-third to one-half of the housing's circumference. Additionally, the inlet should be above the surface level of any oil pool in the sump. A coalescing demister filter is located within the housing between the inlet and the outlet. The housing may include a wall for sheltering the filter from agitated areas of the gearbox. The filter is configured to remove substantially all of the oil from the vent gas stream. The filter may also have an outlet end which is sealed from the oil sump. The filter may also be pleated and enhances oil coalescence.