Abstract: 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.

Abstract: This document presents an apparatus for a flexible air filter media that can be configured for shipping and storage having one or more flexible inserts mounted to the filter media along one or more portions of the accordion folds of the air filter material. The current invention permits the air filter apparatus to fold along both X and Y axes, create a tri-fold, and bend in a manner that provides for a much smaller volume for shipping purposes. The invention also permits attaching the flexible material to the center of the filter media and also inserts which allow sections of the air filter media to be nested one into another to reduce both shipping and storage volume.