Cooling Tower Filtration: The Role of Sump and Air Intake Screens

Cooling towers rely on effective filtration to maintain efficient and reliable operation, but not all screens are designed to perform the same function. If you’ve heard terms like sump screens or air intake screens and wondered what the difference is, you’re not alone. These two components play very different roles in protecting your system. Understanding how they work together can help you avoid costly downtime, protect sensitive equipment, and improve your overall cooling tower performance.

What Are Air Intake Screens?

Air intake screens are installed on the outside of the cooling tower, covering the air inlet openings. Their primary role is to prevent airborne debris, such as leaves, grass clippings, cottonwood seeds, insects, and trash, from entering the system, which can clog internal components if not filtered out.

By keeping this debris out, air intake screens protect vital components, including the fill media, distribution decks, and cold water basins. Clean fill media improves heat transfer and reduces the risk of microbial growth, including algae and Legionella bacteria. These screens also help reduce fouling, blocked nozzles, and bacterial buildup, which lowers the frequency of manual cleaning. Regular cleaning of the screen surface is needed depending on environmental conditions.

What Are Sump Screens?

Sump screens, often referred to as traveling sump screens, serve a distinct purpose. Installed inside the sump or basin, they remove floating and submerged debris already present in the water. Even when air intake screens are used, debris can still enter the water from nearby work areas, process contamination, or other parts of the system.

Unlike stationary strainers or static mesh filters that clog easily, traveling sump screens move continuously or intermittently. As they rotate or travel, they lift debris out of the water and deposit it into a collection area for easy disposal. This motion keeps the screen free of buildup, preventing flow restrictions and protecting sensitive downstream equipment, such as heat exchangers, chillers, and condensers. With self-cleaning operation and heavy-duty industrial construction, these screens require minimal maintenance.

Do I Need Both Sump Screens and Air Intake Screens?

Air intake screens act as the first line of defense by keeping airborne debris out, but they cannot fully protect your system from debris already in the water. That’s where sump screens come in. Without a sump screen, debris in the basin can be drawn into piping and downstream equipment, leading to blockages, reduced heat transfer efficiency, and costly unplanned shutdowns.

Facilities that rely only on air intake screens often find their most sensitive equipment remains exposed to damage. Using both sump and air intake screens together creates a complete filtration system, providing cleaner water, reducing manual cleaning, and protecting critical components throughout the cooling tower.

At Cooling Tower Valves and Screens, we specialize in custom traveling sump screens designed to meet your specific needs. Our solutions help extend equipment life, reduce maintenance, and keep your cooling system operating at its best.

Signs It’s Time to Service or Replace Your Cooling Tower Screens

Keeping your cooling tower screens in good condition is essential for maintaining system efficiency and protecting equipment. Over time, wear and clogging can reduce their effectiveness. Watch for these key signs that it’s time for service or replacement:

1. Frequent clogging or reduced water flow
2. Visible damage like tears or corrosion
3. Increased fouling of heat exchangers or chillers
4. Unusual noise or movement in traveling sump screens
5. Rising maintenance costs or unexpected downtime

Regular inspections and timely maintenance help avoid costly repairs and keep your cooling tower running smoothly.

Maintaining both sump screens and air intake screens is essential for protecting your cooling tower system and maximizing its efficiency. By understanding the distinct roles each screen plays and recognizing when they need service or replacement, you can prevent costly downtime and extend the life of your equipment. At Cooling Tower Valves and Screens, we’re committed to providing custom solutions that keep your operations running smoothly and reliably. Contact us to discover how our high-quality sump screens can help protect your cooling tower investment.