Abstract: A filter retaining apparatus and method for installing a thicker filter in an existing conventional return air duct in a conventional heating and air conditioning system. The filter is commercially available but is thicker than one conventionally used in such systems. A thicker filter provides more efficient air filtration and has a longer life, thus, requires less frequent cleaning or replacement. The retaining apparatus is capable of retaining the thicker filter and is adaptable to the existing return air duct opening without modification of the existing opening or the grill cover. The apparatus has the same length and width dimensions as the existing thin filter and is mounted on the same landing surface. The greater depth of the apparatus extends into the air duct. Thus, from the room interior it is not possible to detect the use of the apparatus. The greater depth of the apparatus retains the thicker commercially available filter.

Abstract: A filter retaining apparatus and method for installing a thicker filter in an existing conventional return air duct in a conventional heating and air conditioning system. The filter is commercially available but is thicker than one conventionally used in such systems. A thicker filter provides more efficient air filtration and has a longer life, thus, requires less frequent cleaning or replacement. The retaining apparatus is capable of retaining the thicker filter and is adaptable to the existing return air duct opening without modification of the existing opening or the grill cover. The apparatus has the same length and width dimensions as the existing thin filter and is mounted on the same landing surface. The greater depth of the apparatus extends into the air duct. Thus, from the room interior it is not possible to detect the use of the apparatus. The greater depth of the apparatus retains the thicker commercially available filter.