Different swamp pad materials are good for different reasons. Aspen is ideal if you’re looking for a water-absorbent material that can provide unparalleled cooling. However, it is prone to flaking that can clog up the swamp cooler pump.
On the other hand, we have foamed polyester that is good if you are looking for a material that doesn’t flake easily. However, since the material isn’t able to absorb and retain water for a long time, it dries fast and doesn’t cool as well as aspen. So, every cooler pad material has its advantages and disadvantages.