An evaporative
cooler basically consists of a
blower and water wetted pads.
Fresh ambient air is cooled by
passing it through the pads. The
air is first passed through the
pre-filter before being passed
through the cooling pads. The
cooling pads cools the air and
also act as secondary air filters.
The fine dust trapped on their
wet surface is washeddown into
the sump, where it is contained.