Cooling tower fill media, also named Cooling tower fill material, one of the successions of vertically arranged, closely spaced panels over which flowing water spreads to offer maximum surface exposure to the air in a film-filled cooling tower. Sheets may be flat, requiring spacers for consistent separation; or they may be formed into corrugated, chevron, and other patterns whose convolutions provide increased heat-transfer capability.

The single most important component of a cooling tower is the fill. Upon its ability to promote both the maximum contact surface, and the maximum contact time, between air and water depends on the efficiency of the tower. And it must promote this air water contact while imposing the lease possible restriction to airflow.  

Its function in cooling tower is to cool down the hot water by increasing the heat dissipation, prolonging cooling water resistance time and increasing the heat exchange area.

The HewiFill® Fill media is a fixed type fill that causes the water to spread into a thin film, flowing over large vertical areas, to promote maximum exposure to the air flow. It has the capability to provide more effective cooling capacity within the same amount of space, but is extremely sensitive to poor water distribution, as well as the air blockage and turbulence that a poorly designed support system can perpetuate. Uniform spacing of the fill sheets is also of the prime importance due to the tendency of air to take the path of least resistance.