Help With Mineral Scale Buildup in Evaporative Coolers

Understanding Evaporative Cooling

• Evaporative cooling is the oldest known method for cooling hot air to make living spaces more comfortable. The ancient Egyptians hung wet fabric to allow wind blowing through it to cool the air. The physical sensation of evaporative cooling is similar to the chill that people feel after getting out of a swimming pool. Evaporative coolers incorporate the practice of ancient Egyptians into machinery that recirculates air from outside.

  Swamp coolers offer people who live in hot, dry places with very little humidity a practical and somewhat energy-efficient way to cool their spaces. Warm air is drawn into the unit by a fan wheel. As water drips on the upper edges of each vertical pad, the air that is blown through the pad cools from the humidity. An added benefit is that this type of cooling removes dust and pollen from the air, aiding people with respiratory problems.

Water Usage

• Many factors determine the amount of water used by evaporative coolers. These include the size of a home or building, the location of the structure with relation to the sun, window size and landscaping. Most evaporative coolers recirculate water that drips from the pads to conserve water. A bleed-off valve that is present on some coolers allows some of the recirculating water to drain out as a way to minimize mineral buildup on the porous pads. One of the problems with a bleed-off valve is the potential increase in water use by as much as 50 percent.

Minimizing Mineral Scale

• Another more water-wise way to reduce mineral buildup is through a dump pump in the system. This type of device dumps water from the drip pan at regular intervals. By dumping this small amount of water regularly, more of the water recirculates through the system, eliminating the need to replenish the lost water. Additional water is used to flush the system out and prevent it from becoming saturated with mineral deposits.

Maintaining Evaporative Coolers

• Regularly draining and cleaning the cooler saves work and money in the long run. Removing built-up mineral deposits and sediment allows the cooler to run more efficiently, cooling better and using less electricity and water. All evaporative coolers require major cleaning once each season of use. Coolers that run constantly require frequent maintenance. Once a month, examine filters, pads, the pump and reservoir. On continuously running units, change pads at least twice during the cooling season. Always clean the filters when changing or cleaning the pads.