A conical frustum shaped air cleaner comprised of a porous foam material in multiple layers. A cavity opening is formed at the center section of the flat bottom surface of the cleaner. The airflow resistance through the aforementioned foam material formed in the tapered side section of the cleaner is different from the airflow resistance through the foam material comprising the upper-surface section of the air cleaner. The desired airflow resistance is also controlled by selecting the appropriate number of layers, the appropriate thickness and the appropriate foaming ratio of the applicable foam materials that comprise the side-surface section and upper-surface section of the air cleaner.