Abstract: A mounting for gaseous fluid filters is disclosed particularly suited for filters of the type which include a rigid box frame within which the filter is carried, the frame having opposite faces open for entrance and exit of the gaseous fluid to be filtered, the mounting including an enclosure with supporting tracks therein for the filter frame, the filter being detachably connected at its upper end to the duct system by a flexible leakproof fabric connection and being sealed at the lower end against leakage.