a filtration system for use in connection with a central vacuum system in a hospital or other medical facility . in certain aspects , the filtration system comprises a removable filter for removing contaminants ; a fitting adapted for connection to a central vacuum source / system which provides constant suction , which fitting is positioned between the filter and the central vacuum source ; a flow control valve positioned between the filter and the fitting ; wherein the relative positions of the fitting , flow valve and filter prevent contaminants from being discharged into the central vacuum system . in other aspects , the system provides variable filter life based upon variable flow .