A frame assembly for releasably maintaining an air filter. In some embodiments, the frame assembly includes a thermoformed body integrally forming a base, opposing side walls, opposing end walls, and at least one closure sub-assembly. The frame assembly is configured to releasable retain an air filter relative to the base via the closure sub-assembly. In other embodiments, the frame assembly defines, in a flat state, foldable side and end panels at the perimeter edges of a central grid panel; the frame assembly can be transitioned to a final state for receiving an air filter by folding the panels. The frame assemblies of the present disclosure are re-usable, allowing a user to replace a “used” air filter with a “new” air filter.

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.

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.

An air filter assembly includes a pleated air filter media having an upstream surface, a downstream surface, a first side end, and a second side end; a wire netting adjoined to the downstream surface of the air filter media; and a graspable end member adjoined to each of the first and second side ends of the air filter media. The assembly further includes a frame configured to releasably retain the air filter media, the frame having first and second ends walls and first and second side walls; a closure assembly for securing the air filter media within the frame, the closure assembly comprising a spring-loaded fastener pivotably coupled to at least one of the first and second side walls and configured to fasten to at least one of the first and second end walls; and an efficiency grid retained within the frame.

A framed air filter, comprising an air filter media having a generally rectangular perimeter with four major edges, and a frame comprising four frame portions. Each frame portion of the frame is mounted on one of the four major edges of the air filter media and met with neighbouring frame portions to form corners of the frame. At least one of the frame portions is provided by a frame piece that comprises first, second, third and fourth panels that are foldably connected by fold lines, which single frame piece is wrapped in a generally rectangular configuration so that the fourth panel comprises a forward terminal end that is abutted proximal a rearward major surface of the first panel. The third panel provides a rear wall of the frame portion with an inner edge provided by a fold line connecting the third panel to the fourth panel, wherein the inner edge is bowed.

A device for filtering air comprising a base, a fan functionally attached to the base, an air filter releasable attached to the base, and a substantially air impermeable outer sleeve is provided.

A filter unit for use with a filtrating fluid flow system is configured to receive a flow of a fluid containing particulate matter. The filter unit comprises a filter structure formed of a filter material configured to at least partially filter the particulate matter from the flow of fluid. The filter unit further comprises an entry plate located proximate the filter structure entrance. The filter structure and the entry plate together define a fluid cavity within the filter unit, the entry plate having at least one orifice defined therein through which the flow of fluid can pass into the fluid cavity. The orifice is configured to form a choke, creating a Venturi effect for temporarily increasing the velocity of the flow of fluid through the entry plate and within the fluid cavity, and onto the filter material.

An air filter unit for purifying air. The air filter unit includes a filter body extending along an axis, a first filter frame and a second filter frame arranged on opposite ends of said filter body. Each of the first and second filter frame includes four elongated frame members turnably secured to each other. The four elongated frame members are turnably secured to each other such that the filter body could be arranged in a first and a second state. The first state is such that the filter body is folded to reduce the volume of the filter unit and the second state is such that the filter body is assembled.

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.