An air filtration system includes a housing that is interchangeably positioned within a plenum that is in fluid communication between the housing and a room. A fan is positioned within the housing and configured to draw contaminated air from the plenum. At least one filter member is positioned within the housing and configured to filter the contaminated air. A flexible duct is configured to channel filtered air from the housing to the room. The flexible duct is configured to enable the interchangeability of the housing.