A base assembly for air handlers having a filter. Four metallic legs each have a distal end. The metallic legs also have first through holes at first predetermined distances from their respective distal ends. The metallic legs have a rectangular or square cross section, and each distal end mounts to a floor. First and second metallic upper frames have vertical extensions to telescopically receive the four metallic legs respectively. The first and second metallic upper frames further have braces member and air filter C-shaped tracks. The first and second metallic upper frames each further have elongated male horizontal arms and elongated female horizontal arms that join whereby the air filter C-shaped tracks face each other to receive a filter.