The Two Fundamental Types of Fill
Fills are categorized by how they create water surface area:
| Type | How It Works | Best For | Material |
| Splash Fill | Breaks water into droplets. As water falls, it hits staggered splash bars (grids, beams, or laths), continuously breaking into smaller droplets. | • Water with high suspended solids/silt • Applications where fouling is a major concern • Low-cost, rugged applications | • PVC (extruded bars) • Wood (traditionally redwood or fir) • Polypropylene |
| Film Fill | Spreads water into thin sheets. Water flows down corrugated, closely spaced sheets, forming a thin film over a large surface area. | • Highest thermal efficiency (primary choice for most modern towers) • Clean water with good treatment • Where space/cost efficiency is critical | • Thin, corrugated PVC sheets (most common) • CPVC (for higher temps) • Polypropylene |