Panel filter elements having a pleat block and a seal member are described. The panel filter elements are arranged such that the seal members and pleat blocks can have curved and/or angled elements. The seal member of a filter element may be curved, angled, twisted, and/or has a varying cross-section. The inlet and outlet faces of the pleat block of the filter element may be curved and/or twisted instead of planar. In some arrangements, both the seal member of the filter element and the faces of the pleat blocks can be curved and/or twisted. The described filter elements may be may be flexible, such that the shape of the filter element and/or seal can conform to the shape of a filter housing, or rigid, such that the shape of the filter element remains substantially the same before and after installation into a filter housing.

An air filter device including an air filter unit and an expansion unit. The air filter unit includes a filter media assembly maintained by an outer frame assembly. The outer frame assembly defines exterior length, width and depth dimensions of the air filter device in an initial state. The expansion unit provides one or more of an expanded length, width or depth in an expanded state of the air filter device. Portions or an entirety of the expansion unit can provided apart from the air filter unit in a deliver condition of the air filter device, or can be assembled to the air filter unit prior to delivery to a user. The air filter devices of the present disclosure are useful with a wide variety of differently size air handling devices, able to readily seal with an air handling device compartment via the expansion unit.

A filter member having an elongated body with a first end, with an extension member at the first end, wherein the extension member is adjustable between a first length and a second length. In one non-limiting embodiment, the extension member is threadably moveable between the first and second lengths. A filter system includes a vessel into which is positioned the filter member. A pipeline system will include the filter system.

A filter element is provided for being removably arranged in a filter housing, the filter element including a filter material body. The filter element is adapted to assume a first state, in which it has a substantially flat shape, and a second state, in which it has such a curved shape, such that opposite outer peripheral sides of the filter element are directed towards each other and in which it is adapted for a filtering operation. The filter element is adapted to be locked in the second state when arranged in the filter housing. A filter system is also provided including a filter element and an anchoring device adapted to be arranged between the opposite outer peripheral sides of the filter element when it is curved to the second state.

A collapsible filter having a collapsed position and an expanded position includes a filter media layer having generally parallel pleat edges and a side edge perpendicular to the pleat edge. The filter also has a pair of end caps that are disposed at opposite ends of the filter media layer and are generally parallel to the pleat edges. A flexible side seal is attached to both the end caps but is not attached to the filter media layer. In an expanded position, the flexible side seal extends between the end caps and abuts against the side edge of the filter media layer.

An expandable air filter. The air filter including a filter media assembly, an outer frame assembly, and at least one support member. The filter media assembly defines opposing, first and second major faces and a perimeter. The outer frame assembly is arranged about the perimeter. The support member is connected to the outer frame assembly and extends across the first major face. Further, the support member defines a line of separation at which the support member can be separated into first and second segment to permit expansion of the air filter. The filter media can form a plurality of pleats, with at least one pleat being free of bonding to the outer frame assembly. The unbonded pleat experiences expansion as the air filter transitions to an expanded state. The air filter can be configured for expansion in one or both of a length and width direction.

The present invention provides an air purifier. The air purifier according to one preferred embodiment, of the present invention may comprise: a housing; a blowing unit installed in the housing so as to draw in external air; and a filter unit having filtering surfaces, through which the air passes and which are disposed in multiple directions, and an air inflow space, which has at least a part thereof surrounded by the filtering surfaces disposed in the multiple directions and into which the air discharged from, the blowing unit flows.

A collapsible HVAC filter that includes pleated filtration media having side members mounted on opposite sides of the filtration media. The filtration media collapses to reduce filter volume. Supports maintain spacing between the side members when the filtration media is expanded. The supports may extend into openings on the upstream and downstream sides of each of the side members. The collapsed filter occupies little space relative to the expanded filter, and can be expanded to form a completed filter with little effort required by the end user.

A device that attaches to an air filter to modify the dimensions to allow fitment. The invention allows the use of a standard air filter in a non standard sized return filter grill or air handler.

A filter element to be inserted into a filter housing, has a filter medium with a rim, wherein the rim is connected to an injection-molded frame or at least one injection-molded frame element, providing a flexibly bendable filter element using a frame made of plastic attached by injection molding, wherein the frame or at least one frame element is made of plastics of different hardnesses in alternation in at least one extension direction, such that the filter element can be bent flexibly at least in part by deforming the filter medium and the frame or frame element.