This invention relates to a method and apparatus for the rooftop support of an airconditioning unit and for the automatic continuous cleaning of the treated air that circulates through the supported air conditioning unit, thus an Auto Filter Curb. The unique design of the system places the automatically rolled filter inside the plenum curb and within the return air stream to protect the evaporator coil from the accumulation of lent and dust, thus helping to prevent the compressors from overheating, and consequently reduce maintenance costs.