Abstract: A system for circulating air which includes particles, bacterial organisms, and odoriferous material includes a fan coupled to ducting of the air circulation system for causing movement of air in a stream through the ducting; a filter holder configured to hold an air filtering device supported within the air stream; and an air filtering device for removing from the circulating air the particles, bacterial organisms, and odoriferous material. The air filtering device may include multiple filter elements having multiple layers of differing filtering materials, which may include activated carbon and potassium permanganate.

Abstract: An HVAC filter having a pleated paper filter and a plastic pre-filter, the filter and pre-filter are mounted in a parallel relation in the frame. The plastic pre-filter includes a plastic mesh having a plurality of openings, and an irregular surface on the inlet side to prevent matting of filtered material.

Abstract: A filter media for an air filter includes at least two layers of filter material with the materials being different. The layers are joined together by a stiffening grid fabricated from a metal or plastic. Glue such as hot-melt glue is disposed on both sides of the grid to attach the sides of the grid to the respective layers. Depending upon the application, the filter media may be pleated.

Abstract: An HVAC filter having a pleated paper filter and a plastic pre-filter, the filter and pre-filter are mounted in a parallel relation in the frame. The plastic pre-filter includes a plastic mesh having a plurality of openings, and an irregular surface on the inlet side to prevent matting of filtered material.

Abstract: A filter apparatus for a reusable one piece filter frame housing and a filter media for use in a forced air ventilating system. The one piece filter frame housing having integrally formed fasteners to releasably secure a replaceable filter media. The filter frame housing further having an "I" beam structure to enhance filter frame strength. The filter frame housing also having an electrostatic charge.

Abstract: An adjustable air filter for use in heating, ventilating, cooling, and forced air systems. The air filter includes a media for filtering air and adapted to be cut with scissors, and a frame embracing the peripheral edges of the media. The frame includes a pair of male sections and a pair of female sections respectively telescopingly receiving the male sections. Also, the frame is adapted to be cut with scissors and is preferably formed of polyvinyl chloride. Each of the male sections includes a T-shaped projection and each of the female sections includes a complementary shaped T-shaped slot adapted to telescopingly receive the T-shaped projection for preventing inward separation of the sections from one another. In the preferred form the media is of the electrostatic type and includes at least one layer of polypropylene woven in an egg-crate pattern. Also, the layer preferably includes a pad of washable polyester material.

Abstract: A trimmable range hood filter for covering both an inlet opening of a range hood and a light on the range hood adjacent the inlet opening. The filter includes a rectangular filter element, four non-telescoping frame members sequentially arranged to form a rectangle, attachment clips joining the frame members at the corners, a translucent plastic pane, and a separator bar with an "S"-shaped cross-section joining an edge of the pane to an edge of the filter element. The pane and filter element, joined by the separator bar, fit within inwardly facing channels of the frame members. The various parts of the range hood filter, i.e., the filter element, the pane, the separator bar, and the frame members, are trimmable by scissors to fit the range hood dimensions, with the filter element covering the inlet opening and the pane covering the mouth of a cavity in which the range hood light sits.

Abstract: An adjustable air filter for use in heating, ventilating, cooling, and forced air systems. The air filter includes a media for filtering air and adapted to be cut with scissors, and a frame embracing the peripheral edges of the media. The frame includes a pair of male sections and a pair of female sections respectively telescopingly receiving the male sections. Also, the frame is adapted to be cut with scissors and is preferably formed of polyvinyl chloride. Each of the male sections includes a T-shaped projection and each of the female sections includes a complementary shaped T-shaped slot adapted to telescopingly receive the T-shaped projection for preventing inward separation of the sections from one another. In the preferred form the media is of the electrostatic type and includes at least one layer of polypropylene woven in an egg-crate pattern. Also, the layer preferably includes a pad of washable polyester material.