Automatically renewing air filter

An air filter assembly, comprising:

• a filter media cartridge and a filter frame connected at a first end to the filter media cartridge;
• the filter media cartridge comprising:
• a cartridge body defining an internal volume;
• an aperture extending along a length of an upper portion of a cartridge body wall where the filter frame is connected, the aperture providing a channel of communication between the internal volume and an air flow opening defined by the filter frame;
• a supply roller for supplying a filter media from the internal volume;
• and a take-up roller for receiving the filter media in the internal volume;
• wherein the filter frame is a rectangular cuboid having a longitudinal axis and a lateral axis, the filter frame being configured to be received by an air handler filter slot of a heating, ventilation, and air conditioning (HVAC) system;
• and
• wherein the filter frame comprises a pair of side frame sections, wherein each respective side frame section includes an expansion joint that allows the side frame section to be lengthened or shortened about the longitudinal axis to accommodate air handler filter slots of various widths;
• wherein each expansion joint is a telescoping, nested portion of the respective side frame section;
• and
• wherein at least one expansion joint or at least one side frame section includes one or more locking mechanism such that when the side frame sections are extended outward and away from the expansion joints they can be locked into position and can maintain that position during use.

A method of filtering air before the air passes through an air handler filter slot of a heating, ventilation, and air conditioning (HVAC) system, the method comprising:

• providing an air filter assembly comprising:
• a filter media cartridge and a filter frame connected at a first end to the filter media cartridge;
• the filter media cartridge comprising:
• a cartridge body defining an internal volume;
• an aperture extending along a length of an upper portion of a cartridge body wall where the filter frame is connected, the aperture providing a channel of communication between the internal volume and an air flow opening defined by the filter frame;
• a supply roller for supplying a filter media from the internal volume;
• and a take-up roller for receiving the filter media in the internal volume;
• wherein the filter frame is a rectangular cuboid having a longitudinal axis and a lateral axis, the filter frame being configured to be received by an air handler filter slot of a heating, ventilation, and air conditioning (HVAC) system;
• wherein the filter media extends about the longitudinal axis of the filter frame from and back to the filter media cartridge such that a double layer of the filter media covers the air flow opening;
• wherein the filter frame comprises an end roller positioned at a second end of the filter frame, wherein the filter media from the supply roller is routed through the air flow opening from the first end to the end roller, which then returns the filter media to the first end;
• wherein the filter frame comprises a pair of side frame sections separate from the filter media and located along longitudinal perimeters of the filter media and extending from the first end to the second end of the filter frame, wherein each respective side frame section comprises an expansion joint that allows the side frame section to be lengthened or shortened about the longitudinal axis to accommodate air handler filter slots of various widths;
• wherein each expansion joint is a telescoping, nested portion of the respective side frame section;
• and
• wherein at least one expansion joint or at least one side frame section includes one or more locking mechanism such that when the side frame sections are extended outward and away from the expansion joints they can be locked into position and can maintain that position during use;
• installing the air filter assembly into the air handler filter slot;
• and
• connecting the air filter assembly to a power source.