Preventative Swamp Cooler Maintenance for Scale Buildup

What Is Scale?

• Scale is often an accumulation of calcium and magnesium carbonate. As the hard water evaporates, mineral deposits build up in the cooler pads, the water reservoir and the metal components of the swamp cooler. When there is a large amount of scale, the cooling capacity and the efficiency of the swamp cooler decreases. More rust accumulates, and the life expectancy of the swamp cooler decreases. Additional maintenance is often required.

Bleed-Off Valves

• Instead of allowing water recirculation in the swamp cooler, a bleed-off valve drains part of the water out of the swamp cooler. The water is often used for nearby plants. A bleed-off valve reduces scale buildup, but it increases the swamp cooler water use by up to 50 percent. Follow the manufacturer’s instructions for installation and proper valve adjustment. Some companies sell devices that replace all the water in the swamp cooler reservoir every few hours.

Water Additives

• Add commercially prepared water additives to the water reservoir to reduce scale buildup. Some are available in liquid form. Additives are also available in poly mesh bags that sit at the bottom of the water reservoir. Read the manufacturer’s instructions to be certain the additive is safe for use in houses and buildings. Conditioners for cooler pads are available for purchase, and those conditioners reduce scale formation in the pads.

Water Filters and Softeners

• Swamp cooler water filters fit into the water intake line or are placed in the water reservoir. Avoid the use of water softeners. The sodium in softened water may build up on the cooler pads and metal parts.

Cleaning

• Regularly hose the cooler pads and the water reservoir to wash off scale deposits. Replace the cooler pads as necessary, usually at least once per year. Depending on the type of water, cleaning may be necessary every month during the cooling season. At a minimum, clean the pads and the water reservoir during the winterization of the swamp cooler. Vinegar can be used to dissolve the scale buildup in the water reservoir.