Abstract: The present disclosure generally relates to air filters expandable from a collapsed arrangement to an expanded, end-use arrangement and to methods of making, using, and installing such air filters. Some embodiments relate to an air filter having an expanded state and a collapsed state. The air filter includes a filter media assembly including (1) filter media including a plurality of pleats, (2) first and second opposing sides, and (3) first and second opposing ends. The air filter also includes a shape retention structure capable of being connected to at least a portion of the filter media assembly and capable of retention the filter media assembly in the expanded state. A spacing distance between adjacent pleats in the filter media is greater in the expanded state of the air filter than in the collapsed state of the air filter. In some embodiments, the air filter is an HVAC air filter.

Abstract: A filter frame assembly includes a main frame including a first end and a second end, and a spindle unit disposed at the first end. The spindle unit includes a spindle frame, a dispensing spindle non-rotatably coupled to the spindle frame, and a receiving spindle rotatably coupled to the spindle frame. Each of the dispensing spindle and the receiving spindle is configured to receive a filter web thereon in a wound configuration. The main frame is insertable through a filter slot of an HVAC system from the second end, such that the main frame is at least partially received within the HVAC system and the spindle unit is disposed external to the HVAC system. The filter web extends from the dispensing spindle towards the second end of the main frame and extends back to the receiving spindle, while being at least partially received in the main frame.

Abstract: A framed air filter that includes air filter media and a frame with four frame portions. At least one frame portion includes an inner sidewall and an outer sidewall that meet at a sidewall junction. The sidewall junction extends along a score line that includes at least one cut-scored segment and one crush-scored segment.

Abstract: A framed air filter that includes air filter media and a frame with four frame portions. At least one frame portion includes an inner sidewall and an outer sidewall that meet at a sidewall junction. The sidewall junction extends along a score line that includes at least one cut-scored segment and one crush-scored segment.