LITTLE ROCK, AR — Has your traditional a/c service and maintenance work been in a slump? Are qualified workers hard to find? If you live in an area with a lot of residential evaporative cooling systems, you may be able to lessen both problems at once.

James Pettry, vice president of sales and marketing for Essick Air Products/Champion Cooler Corp., a manufacturer of metal and UL-approved polypropylene evaporative coolers here in Little Rock, says that maintaining and upgrading evap cooling systems “can be lucrative, because there aren’t that many people willing to maintain them right now.”

Likewise, many consumers, such as senior citizens, don’t want the hassle or simply can’t perform the maintenance, which Pettry says is relatively simple, especially compared to refrigeration-based cooling systems.


Let’s say you have a limited number of technicians qualified to perform air conditioning service involving refrigerants, but you have a couple more people with a mechanical aptitude, just starting out, who are underutilized. Pettry says that putting them to work doing evap cooling maintenance, after making sure they know what to do and what not to do, is a profitable use of their still-limited skills.

“It doesn’t take a rocket scientist” to perform residential evap cooling maintenance, Pettry says. “Contractors can take their minimum-wage people and put them to work doing this. With evap cooling, you’re talking water, a blower, and a belt: change the pads and away you go.”

There are plenty of upgrade opportunities too, Pettry says. “A typical metal evap cooler will rust no matter what you do,” he says.

Moreover, “Contractors could make a lot of money refurbishing older units. They can upgrade from an [older model] ‘tried-and-true’ evap cooler to a cell-deck, rigid-media unit. It’s got the same duct openings,” he adds. “It’s a drop in.”

And the homeowner gets a higher-efficiency product. “It’s the same as going from a 10- to a 12- or 14-SEER unit,” Pettry says. Maintenance on the newer units is less bothersome, too. You change filters. “A good dealer could roll it in with their package,” he says.

In the meantime, there are plenty of older units out there that need regular maintenance — at least twice during the cooling season, some manufacturers say.

Figure 1. A cutaway drawing of an evaporative cooling unit. (Courtesy of Essick Air Products.)


With some training, Pettry says less-experienced workers with a good mechanical aptitude could perform most, if not all, of the evaporative cooler maintenance steps outlined below.

After they perform the service/ maintenance, a salesperson could follow up to see if the customer would benefit from a parts upgrade or a new system installation.

Contractors can gauge their employees’ ability to perform evap cooler maintenance by asking them if they could perform the following tasks, provided by Essick Air Products/Champion Cooler Corp.

Can your employees:

  • Replace the pads?

    Pads provide better cooling via unrestricted airflow; they should be replaced at least two times during the season because of mineral deposits left behind in the water evaporation process. Cooler pads can also become clogged with dust, pollens, and mildews, which restrict the flow of air. This overworks the motor, causes dry spots on the pads, and impairs the performance of the customer’s cooler.

    While changing the pads, clean the louvers and water troughs of debris and mineral deposits. It is critical that the water trough openings remain open for even water flow onto the pads.

  • Clean water reservoir/bottom pan?

    Drain any standing water via the cooler overflow/drain tube. Remove dissolved salts, silt, old pad fibers, etc., with a solution of water and vinegar.

    If necessary, use a plastic scraper to remove mineral deposits. Be careful not to scratch through the protective coating.

  • Service the motor and blower wheel?

    Make sure that the motor and blower wheel turn freely. If not, first turn off power to the cooler; grasp the V-belt midway between the two pulleys and turn the motor and blower wheel a few revolutions. Rotating the blower wheel usually breaks the armature or wheel free and will recoat the bearings with oil.

  • Check the water impeller pump?

    Make sure the pump impeller turns freely and distributes water evenly to all pad surfaces or water troughs. If it will not rotate, replace the pump according to the manufacturer’s directions.

    While checking the pump impeller, examine the water distribution tubes — make sure they are not clogged. If they are clogged, open them with a flexible wire. Again, it is imperative that water flows onto the pads evenly.

  • Check V-belt tension?

    First, check to see that the V-belt is not cracked or frayed. If so, replace it. Allow about 3/4-in. play in the new belt’s tension.

    Once the tension is set, tighten the bolts to the motor. Oil the blower wheel bearings (on each end) using a 20-weight, nondetergent motor oil. Most coolers have “oiler” caps to insert the oil. Do not over-fill. If the motor is not permanently sealed and lubricated, look for oiler caps on the motor shaft, too.

  • Check the float valve?

    Adjust the float inside the water reservoir pan higher or lower so that the water level stabilizes about 1/2 in. below the top of the overflow tube.

    If water is running over the overflow tube, the water level is too high. If the tube is leaking around the gasket where it is attached to the cooler reservoir bottom, the nut may need to be tightened or the gaskets may need to be replaced.

  • Make sure dampers are open?

    Remove the slide-in damper at the cooler, and/or at the furnace air handler. If the house has a manual slide-in damper, it should be located where the cooler air outlet is connected to the ducts that enter the home.

    Automatic barometric dampers are air operated by air movement and automatically open when the blower is turned on; if no air is entering the home when the cooler is operating, the barometric damper could be stuck in the closed position.

  • Check for leaks?

    In metal coolers, leaks can be patched with a marine sealer. The sealer, which can be applied with a small trowel or stiff brush, should be spread along the bottom of the cooler and along the sides to cover above the water level.

    To reduce the amount of mineral deposits that can build up in a cooler reservoir and lead to corrosion and leaking, Essick Air recommends that the water be changed monthly. A simple way to do this, the company says, is to install a bleed-off kit that continually flushes out about 10% of the water that enters the cooler.

    Regular evaporative cooler maintenance helps customers keep their energy costs down, helps contractors keep less-experienced workers working and learning, and helps contractors keep an eye out for possible replacements and upgrades. Like Pettry says, it’s not rocket science.

    For more information, contact Essick Air Products/Champion Cooler Corp., 5800 Murray St., Little Rock, AR 72209; 501-562-1094; 800-643 8341; 501-562-9485 (fax); (e-mail).

    Publication date: 05/13/2002