Collapsible auto expanding media filter

Collapsible filter assemblies for use with pleated or other filter media are disclosed. A collapsible filter assembly can include at least one filter element including a filter media supported within a collapsible filter frame. The filter frame can include a number of frame members each including a number of frame panel sections hingedly connected to each other. Each frame member can be configured to bend or fold outwardly away from the sides of the filter media to permit the filter frame to be actuated between a collapsed position and an expanded position. A number of elastic members can be coupled to opposing sets of frame members in order to bias the filter frame in the expanded position, causing the filter assembly to self-expand when removed from its packaging. During installation, such auto-expanding feature reduces the amount of time required for the installer to place the filter assembly into service.