A purifier cassette comprising: a purifier body that comprises a set of media cavity sidewalls at least partially defining a media cavity, the set of media cavity sidewalls comprising a first sidewall (123, 234), a second sidewall (124, 236), a third sidewall (125,210) and a fourth sidewall (126,220), the first sidewall (123,234) opposite the second sidewall (124,236) and the third sidewall opposite the fourth sidewall (126,220); one or more tension members coupled to the first sidewall (123, 234) and the second sidewall (124, 236) of the media cavity; the one or more tension members running parallel to the third sidewall and fourth sidewall and dividing the media cavity into a plurality of parallel lanes; a purifier element disposed in each of the plurality of lanes of the media cavity, wherein the purifier elements comprise a compressed generally rectangular pleat pack arranged with a first set of pleat tips oriented to point at a first side cover facing an upstream portion of the media cavity and a second set of pleat tips are oriented to point at a second side cover facing a downstream portion of the media cavity disposed in each of the plurality of lanes; a first purifier port (108,110) fluidly connected to the media cavity; a second purifier port (112,114) fluidly connected to the media cavity; a first end cap and a second end cap the first end cap comprising the first purifier port and the second end cap comprising the second purifier port; the first side cover comprising the first sidewall and defining a first set of flow channels disposed along the first sidewall, the first set of flow channels connected to the first purifier port; and the second side cover providing the second sidewall and defining a second set of flow channels disposed along the second sidewall, the second set of flow channels being on an opposite side of the plurality of parallel lanes from the first set of flow channels and coupled to the second purifier port, the flow cannels being configured to exchange fluid with respective first and second opposite sides of the plurality of lanes. a purifier body that comprises a set of media cavity sidewalls at least partially defining a media cavity, the set of media cavity sidewalls comprising a first sidewall (123, 234), a second sidewall (124, 236), a third sidewall (125,210) and a fourth sidewall (126,220), the first sidewall (123,234) opposite the second sidewall (124,236) and the third sidewall opposite the fourth sidewall (126,220); one or more tension members coupled to the first sidewall (123, 234) and the second sidewall (124, 236) of the media cavity; the one or more tension members running parallel to the third sidewall and fourth sidewall and dividing the media cavity into a plurality of parallel lanes; a purifier element disposed in each of the plurality of lanes of the media cavity, wherein the purifier elements comprise a compressed generally rectangular pleat pack arranged with a first set of pleat tips oriented to point at a first side cover facing an upstream portion of the media cavity and a second set of pleat tips are oriented to point at a second side cover facing a downstream portion of the media cavity disposed in each of the plurality of lanes; a first purifier port (108,110) fluidly connected to the media cavity; a second purifier port (112,114) fluidly connected to the media cavity; a first end cap and a second end cap the first end cap comprising the first purifier port and the second end cap comprising the second purifier port; the first side cover comprising the first sidewall and defining a first set of flow channels disposed along the first sidewall, the first set of flow channels connected to the first purifier port; and the second side cover providing the second sidewall and defining a second set of flow channels disposed along the second sidewall, the second set of flow channels being on an opposite side of the plurality of parallel lanes from the first set of flow channels and coupled to the second purifier port, the flow cannels being configured to exchange fluid with respective first and second opposite sides of the plurality of lanes.