Filter apparatus (6) in particular passenger compartment filter apparatus, for example for a motor vehicle (1), comprising a filter element (8) having a filter medium body (9) and a frame (10) surrounding the filter medium body (9), wherein the frame (10) features opposite lateral surfaces (11, 12), a plurality of engagement elements (22a to 22d), and a filter housing (7) featuring, on two opposing wall sections (24, 25), in each case two engagement counter elements (28a to 28d) in which in each case one of the plurality of engagement elements (22a to 22d) can be accommodated in a positive fitting manner, wherein the engagement counter elements (28a to 28d) in each case are designed as a groove in the respective wall section (24, 25) of the filter housing (7) and feature: an insertion section (31) which, when the filter element (8) is mounted in the filter housing (7), permits an insertion movement of the respective engagement element (22a to 22d) substantially along the throughflow direction (L), and a locking section (32) connected to the insertion section (31) and angled with respect to the insertion section (31), wherein a respective engagement element (22a to 22d) is disposed on a respective lateral surface (11, 12) of the filter element (8) when the filter element (8) is mounted in the filter housing (7), extends away from the filter medium body (9), and is held in a respective locking section (32).

A filter assembly that includes a filter housing with a housing interlocking feature, a filter cover with a filter cover interlocking feature, and a filter element with a filter element interlocking feature is disclosed. The filter element is positionable within the filter housing, and the filter cover is attachable to a top portion of at least one of the filter element and the filter housing. The housing interlocking feature, the filter cover interlocking feature, and the filter element interlocking feature are interlockable with each other and extend in a nonplanar configuration along at least one side of the filter element when the filter housing, the filter cover, and the filter element are assembled together.

A housing assembly for an HVAC system, including: a casing with an air inlet and an air outlet, forming a first portion of an air conduit between the air inlet and the air outlet, the air conduit being configured to guide airflow between the air inlet and the air outlet; a removable cover, attached to the casing and forming a second portion of the air conduit. The casing and the removable cover form a filter slot with a filter volume, configured to receive a filter of complementary shape, the filter slot including four sidewalls for constraining the filter, an inlet aperture and an outlet aperture for allowing the airflow between the air inlet and the air outlet. The air conduit includes a guidance wall neighboring at least one of the filter slot sidewalls, the second portion of the air conduit including a part of the guidance wall.