An air purifier has an air filter including: a filter member including a plurality of filtration regions each having a plurality of vertical pleats extending in an up-down direction and side surfaces connected to be rotatable with respect to each other; and a frame having a plurality of supports for supporting the plurality of filtration regions. Each of the plurality of supports includes a groove having a shape corresponding to any one of an upper edge and a lower edge of each of the filtration regions. Each of the filtration regions is supported by the supports by at least a part of the upper edge or the lower edge being inserted into the groove.

A filtering device, including: a filter layer, where the filter layer is enclosed into a cylindrical structure; a support frame includes at least one support ring arranged at the end of the cylindrical structure, the support ring is provided with a plurality of elastic connection portions and a plurality of support ring segments, and two adjacent support ring segments are connected by using one elastic connection portion; the elastic connection portion is capable of being elastically deformed when subjected to an external force and capable of restoring by using its own elastic force; when the elastic connection portion is elastically deformed, an angle at which the end portions of the two adjacent support ring segments are connected changes, which drives a shape of the filter layer to change synchronously; when the elastic connection portion restores, the angle changes, which drives the filter layer to restore to an original shape.

An air filter guard includes a downwind rim that supports an air filter in a filter box of an HVAC air handler. The downwind rim prevents the air filter from deforming, bending, or buckling to create gaps that allow air to bypass the air filter. In particular, the air filter guard prevents an air filter from deforming, bending, or buckling even when the air filter is overdue for replacement and clogged with dust. The air filter guard acts as a sleeve in which an air filter is inserted. The air filter guard and air filter are then placed in the filter box of an air handler. The air filter guard has inner dimensions that are large enough to receive the air filter while the outer dimensions of the air filter guard are small enough to fit within the filter box.

Collapsible filter frames are described. In particular, collapsible filter frames including at least one top frame portion, at least one bottom frame portion, and at least one joint between the at least one top frame portion and the at least one bottom frame portion are described. The collapsible filter frame is configured to receive a filter media insert, the insertion of which renders the collapsible frame temporarily non-collapsible.

Compound air filters and methods thereof are provided for sequestering airborne contaminants including volatile organic compounds (VOCs) from air streamed through the air filters. An air filter can include a support frame having a shape and size suitable for seating the air filter within an air-filtering system. A compound filter medium can be retained within the support frame to remove the airborne contaminants and VOCs from air flowing through the air filter and the air-filtering system containing one or more of the air filters. A first media layer of the compound filter medium can be pleated with pleats and configured to exhibit a relatively high filtration efficiency and a low air pressure drop across the filter medium. A second media layer of the filter medium can be coupled to the first media layer and configured to maintain a uniform distribution of the pleats with the first media layer.

A frame for a foldable and disposable air filter media is disclosed. The frame has a frame base and a frame cover having a size to overlap the air filter media. The frame cover is attached to the frame base by hinges allowing movement of the frame cover between an open position and a closed latched position. The closed frame holds the air filter media between the frame base and frame cover when in the closed position. The frame base includes an air flow monitoring system with an air pressure differential sensor to determine when the filter needs to be replaced. The frame also has capability to hold additional sensors for monitoring environmental conditions. A processor and memory enable collection and storage of sensed data. A communication module on the frame communicates air filter media change requirement to external devices including hand-held devices or a cloud server.

A debris shield is disclosed for preventing debris from being sucked into the recirculate inlet of certain trucks used in the rental truck industry and thereby clogging the air conditioning evaporator coils and other components of the air conditioning system. The shield includes a segmented frame configured to fit over an opening of the system in such a way that any debris sucked into the recirculate inlet within the cab encounters and is arrested by the shield before reaching sensitive components. A method of shielding an automotive air conditioning system from entrained debris also is disclosed.

A lattice filter for use in an inlet housing of a pump assembly including a lattice filter body extending from a filter inlet end to a filter outlet end. The lattice filter having a lattice structure. The lattice filter also includes one or more passageways within the lattice filter body. Each of the one or more passageways includes a passageway inlet located at the filter inlet end and a passageway outlet located at the filter outlet end. Each of the one or more passageways extend from the passageway inlet to the passageway outlet.

A collapsible air cleaner filter is provided. The filter includes a pleated media filter having a first end, a second end, and a filter media extending between the first and second ends, wherein the filter media includes a first plurality of flexible end portions and a second plurality of flexible end portions, the first and second plurality of flexible end portions are separated by a plurality of pleats, and the filter media extends a first length between the first and second plurality of flexible end portions, and an end member coupled to the first end of the pleated media filter, the end member extending a second length parallel to the first length, the first length being greater than the second length.

An air filter assembly includes a filter element having at least one variable dimension, and a frame for engaging and supporting the filter element. The frame may include a plurality of linear segments forming a rectangular configuration, and a plurality of clips for connecting the linear segments together at corners thereof. The linear segments may be L-channel segments, C-channel segments, or may be of other form. Clips may be used for connecting the linear segments together at the corners. The filter element may have a pattern of creases or fold lines to facilitate folding thereof from an expanded configuration to a reduced configuration. A grate may be included for spanning an area bounded by the frame to support the filter element. The grate may have multiple arms and a central hub. An edge treatment may form a seal between the filter element and the frame.