and why they should be installed in evaporative coolers.

The Maintenance Problem

The Bacteria, Mold, Mildew Problem:

Bacteria, mold, and mildew proliferate in warm, humid, and stagnant places where there is a food source. An evaporative cooler that is off for several hours is one of these places. It becomes a breeding ground for these micro-organisms because the wet pads and stagnant water in an evaporative cooler box in the Southwest United States gets warmer as each hour passes. These organisms release spores that become trapped inside the box. Mold and mildew spores have a musty smell. Combined, they have “fishy smell.” When a homeowner, a business owner, or a school teacher runs a cooler on a Monday morning after it has been off for the weekend, millions of spores are blown into the home, workplace, or classroom. To healthy individuals, this is an annoyance that may cause nausea or headaches. To young children, to the elderly, or to someone who has been on antibiotics or chemotherapy, foul cooler air can cause asthma attacks, an allergic, reaction, or in a worst case scenario, pneumonia. Such was the case when elderly members of the American Legion of Pennsylvania attended the 58th State Convention in Chicago in July of 1976. Toxic black mold, when inhaled has caused permanent neurological disorder, in school children in Missouri, caused infant deaths in Ohio, and forced homeowners in Texas and California to abandon their homes.

The Zinc Solution:

Zinc is an anti-fungal element. Zinc oxide is used in many over-the-counter products to control diaper rash and athletes’ foot, which are fungus infestations. Vegetables are washed in solutions containing zinc to prevent mold. When a zinc anode is consumed, its electrons (it releases electrons) prevent the steel pan from getting electrons from water and forming rust.

The by-product of zinc corrosion is zinc oxide and zinc salts such a zinc carbonate and zinc sulfate. The zinc oxide and zinc salts are indigestible to bacteria and other micro-organisms including mold, mildew, and algae. When the water is pumped up into the pads, zinc oxide is carried with the water to the pads. The mold, mildew, and bacteria that live in and consume the wood fibers for food cannot digest the zinc; therefore, they quit multiplying and quit making spores. This makes the air cleaner and it makes the pads last longer. Finally, the zinc ions create zinc salts which precipitate out of the water and collect in the bottom of the pan. The calcium carbonate, calcium sulfate, magnesium carbonate, and magnesium sulfate salts do not form as much in the pads. This is why they stay cleaner. With cleaner pads, the air flows easier which improves the efficiency of the evaporative cooler.

The Maintenance Problem:

Each spring, owners of evaporative coolers have to replace clogged cooler pads, inspect and prevent corrosion of the metal pans, and clean the salts from the bottom of the pans before they can be turned on. At the minimum, this is a two-hour process in which someone has to climb up on the roof of the house to perform this maintenance. Occasionally, a pump, a float, water tubing or other parts also need to be replaced. If an anode is not used, many owners will apply tar to the pan to stop the corrosion so it will not leak water onto the roof of the house. In severe cases the pan leaks so badly that the entire evaporative cooler will need to be replaced.

The Zinc Solution:

If a Sunflower Zinc Anode is installed in the spring, the Zinc Anode will prevent corrosion of the metal pan. It will extend the life of the cooler pads from one year to two or more by reducing the amount of micro-organisms that feed on the wood fibers which make them brittle. The zinc salts settle out in the pan instead of clogging up the pads This is why the pads look cleaner.