Stopping Build Up of Minerals in a Swamp Cooler

Hard Water Deposits on Evaporative Cooler

Swamp coolers, also known as evaporative coolers, use water to cool interior air. They work in hot, dry climates where the water is often hard. By virtue of the evaporation process, some of the dissolved solids in the water are deposited on them and a crust builds up on the pads that interferes with their ability to cool by clogging the pads and cutting down on the airflow coming into the home. Several techniques help cut down on the scale buildup to increase comfort in the home and lengthen the life of the cooler pads.

Things You'll Need

• Fabric softener (optional)
• Bleed off valve (optional)
• Purge pump (optional)
• Water softener (optional)

Instructions

1. Install a bleed off tube. Evaporative cooler pumps come with a 1/4-inch hole that irrigation tubing will fit into. This tube lets a small amount of water trickle out of the cooler at constant rates and tends to keep the water less salty. Locate the tube well away from any plants, even though it is tempting to use that water for irrigating. The salts coming from the water will eventually build up in the soil, killing the plants.

2. Install a purge pump. These pumps are on timers and dump the water in the bottom of the cooler every six hours. They do not remove all the water, just the amount that collects in the bottom of the water pan. As water sits in the cooler, the dissolved solids collect at the bottom, and the purge pumps help keep the water cleaner and the pads free of scale for longer periods.

3. Add a capful of unscented fabric softener to the cooler several times a week. Fabric softener will help keep the minerals from building up on the pads.

4. Install a water softening system. This removes minerals from the water and not only will it keep the solids from building on the cooler pads, it will also keep the lime build up in the house from happening, as well.

Tips & Warnings

• Soaking the pads in vinegar will remove some of the minerals. Hose the pads off well once they have soaked before putting them back into the frames to lose the vinegar odor.

• Always turn off the power to the cooler before servicing it and pull the plug. Some of these steps involve hooking up parts to the pump and swamp coolers have moving mechanical parts that could cause serious injury.

References

• Belen, New Mexico: A Waterwise Guide to Evaporative Coolers
• Home Energy: Installing and Maintaining Evaporative Coolers
• Gila County Government: Evaporative Cooling Tips