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Air-Intake Filtration and Cooling-Equipment Maintenance

July 1, 2007
When facility personnel think of condenser-coil and cooling-tower maintenance, their first thoughts usually surround the hassle the task represents. Power

When facility personnel think of condenser-coil and cooling-tower maintenance, their first thoughts usually surround the hassle the task represents. Power washers, cleaning-solvent hoses, buckets, and other cleaning accessories need to be assembled and moved from unit to unit, on and off of rooftops, and behind buildings and other locations. Each unit has to be opened, housings have to be removed, and internal components have to be power-washed. Then the equipment has to be reassembled before moving on to the next unit.

As unpleasant as this job is, ensuring that cooling equipment provides a comfortable work environment is critical. If cooling equipment fails because of system fouling, building temperature and humidity will rise, causing occupant discomfort and a reduction in work efficiency. Furthermore, with companies relying increasingly on computers, failure caused by overheating can bring business operations to a standstill.


In most regions of North America, cottonwood seed is a major contributor to cooling-equipment fouling. This naturally occurring airborne contaminant (generated by poplar trees) usually affects operations from May through early August. Therefore, HVAC maintenance engineers typically must clean equipment frequently during this period or risk equipment failure. Also in summer, insects, paper, construction debris, birds, and just about anything else that blows in the wind seems to find its way into the cooling equipment. The final seasonal assault comes during fall, when trees drop their leaves, which always seem to collect in condenser coils and cooling towers.

Keeping up with HVAC maintenance during the spring, summer, and fall is nearly a full-time job for most HVAC maintenance engineers. As economic realities cause maintenance budgets and staffing to be reduced, it is becoming increasingly important that companies find effective maintenance solutions to streamline day-to-day HVAC maintenance activities and handle work loads more effectively.


If a company is in a lean maintenance-staffing situation, how high on the to-do list would cleaning condenser coils and cooling towers be? Given that it is time-consuming and hard, dirty work, most people would rank the job pretty low. Unfortunately, if the equipment is in need of cleaning and maintenance is delayed, it will continue to operate at an increasing level of inefficiency until it no longer can support the cooling requirements.

Consider the same to-do list. But this time, think about what would happen if cleaning the cooling towers and condenser coils took only a few minutes per unit. Where would this task fall on the to-do list? While there is no real way of knowing, the likelihood that it would rank higher on the list is good. Furthermore, if cleaning the equipment was as easy as using a broom or rinsing with a hose and did not require equipment opening or disassembly, nearly anyone could perform the maintenance and, thus, the dynamics of the HVAC/cooling-tower maintenance process would change.


Air-intake filtration specifically engineered for use on condenser coils, cooling towers, and other HVAC equipment is a useful way to prevent equipment fouling. Unlike window, bug, and shade screens and conventional filters (roll media, pleated filters, and electrostatic filters) that largely are designed for internal use on air-handling units and forced-air heating systems, air-intake filters are designed to mount on the outside of the equipment. There, they stop airborne debris before it enters the system, where it can be seen and quickly removed using a broom, brush, or shop vacuum or by rinsing with a garden hose. Even the rain has a cleansing effect on air-intake filters, as they do not need to be removed for cleaning. Also, because of the critical airflow requirements of cooling towers and condensing coils, air-intake filters are engineered to be nearly invisible to the airflow on high-volume/high-velocity airflow systems. (Static-pressure drop is less than 1/10-in. wg at an air velocity of 600 fpm.)


Air-intake filters help eliminate problems by reducing HVAC maintenance time and effort. They also can save money.

The benefits of air-intake filters for condenser-coil maintenance include:

  • Preventing debris from getting into coils.

  • Reducing/eliminating annual pressure washing.

  • Reducing/eliminating the need for cleaning chemicals.

  • Helping reduce energy costs because coils stay clean all season long.

  • Reducing maintenance, repairs, and downtime.

The benefits of air-intake filters for cooling-tower maintenance include:

  • Reducing/eliminating sludge buildup in basins by reducing bio-loading.

  • Preventing fill fouling.

  • Preventing the plugging of strainers, blowdown valves, and heat exchangers.

  • Helping reduce algae growth by diffusing sunlight, which supports photosynthesis.

  • Reducing water-treatment-chemical consumption by up to 50 percent.

  • Reducing maintenance and repair costs, downtime, and lost productivity.

Randy Simmons is vice president and general manager of Air Solution Co., a manufacturer of air-intake filtration systems for chiller and condensing coils, cooling towers, rooftop units, and other high-volume/high-velocity air-intake systems. He can be contacted at 513-860-9784.