Disposable air filter sub-assembly

A disposable air filter sub-assembly that includes: (a) air filtration media; (b) a substantially planar air filter frame providing three-dimensional support for the air filtration media; and (c) an air filter frame-connecting means integrated into the air filter frame. The integrated air filter frame-connecting means are adapted to connect a plurality of identical air filter sub-assemblies into an air filter assembly with sufficient structural strength in at least one direction such that the air filter sub-assemblies resists separation when the air filter assembly is extracted from the filter track of a filter bank.