An expandable air filter device. The air filter device includes first and second air filter units and an expansion joint. The air filter units each include a filter media assembly and an outer frame assembly. The filter media assembly defines a perimeter. The outer frame assembly is arranged around the perimeter. The expansion joint is connected to and extends between the outer frame assembly of the first air filter unit and the outer frame assembly of the second air filter unit. In some embodiments, the expansion joint is expandable from a collapsed state to an expanded state. A gap between the first and second air filter units is greater in the expanded state than in the collapsed state, with the expansion joint spanning the gap, serving to impede flow of un-filtered air through the gap during use.

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.

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.

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 addition of a medial longitudinal score line (hinge point) along the longitudinal channels of the filter frame allows for thinner media and/or collapsing the frame on itself which will reduce scrap, save space and save tremendously on shipping costs. The additional score line can be a cut score, skip score, crush score or liquid line. The collapsed filter frame expands upon sliding into the channels of the filter frame media holder whereby the filter frame expands and widens to fit the filter assembly.

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.

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.

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.

In an example, a particulate filter includes a porous filter substrate including a first surface and a second surface. The porous filter substrate is configured to filter gas flowing through the porous filter substrate between the first surface and the second surface. A plurality of conductors are coupled to the porous filter substrate. The plurality of conductors are approximately parallel to each other along the porous filter substrate. The particulate filter also includes a plurality of input nodes in signal communication with the plurality of conductors and configured to receive a voltage signal from an input signal source. The plurality of conductors are configured to generate an electric field on at least one of the first surface or the second surface of the porous filter substrate in response to the plurality of input nodes receiving the voltage signal from the input signal source.

In an example, a particulate filter includes a porous filter substrate including a first surface and a second surface. The porous filter substrate is configured to filter gas flowing through the porous filter substrate between the first surface and the second surface. A plurality of conductors are coupled to the porous filter substrate. The plurality of conductors are approximately parallel to each other along the porous filter substrate. The particulate filter also includes a plurality of input nodes in signal communication with the plurality of conductors and configured to receive a voltage signal from an input signal source. The plurality of conductors are configured to generate an electric field on at least one of the first surface or the second surface of the porous filter substrate in response to the plurality of input nodes receiving the voltage signal from the input signal source.