An air dryer, used in a compressed air system, includes an oil coalescing element for agglomerating oil in compressed air passing through the oil coalescing element in a first direction during a charging cycle and passing through the oil coalescing element in a second direction during a purging cycle. A drying material, which is downstream of the oil coalescing element during the charging cycle and upstream of the oil coalescing element during the purging cycle, reduces moisture in the compressed air during the charging cycle.