Cooling tower fill is by far one of the most important cooling tower components. It could be considered the middle man of the entire process. Many of today's cooling towers use efficient plastic film fills or fill media that maximize the surface area for evaporative cooling processes. Water gets distributed onto the fill, which spreads into thin film. This process increases the water-air interface and allows extra heat to evaporate at a fast pace.
The major factors in choosing fill media are TSS levels or Total Suspended Solids, intended treatment, water make-up and contamination potential. The 2 basic types of fill media are film type fill media (spreads the water out into a thin layer) and splash type fill media (breaks the water up). There is also fill media for specific types of towers such as crossflow fill media and counterflow fill media.