Cooling towers allow water to be cooled by ambient air through evaporation. They have two types of air flow, crossflow and counterflow. In crossflow towers, the air moves horizontally across the downward flow of water. In counterflow towers, the air moves vertically upward against the downward fall of the waterCooling towers allow water to be cooled by ambient air through evaporation. They have two types of air flow, crossflow and counterflow. In crossflow towers, the air moves horizontally across the downward flow of water