How to Prevent Legionella Pneumonia in Swamp Coolers

Legionella pneumophila is an aquatic bacterium that is present almost everywhere in the environment where there is water. Swamp coolers use water evaporation to cool the air going into a building. As a result, swamp coolers may harbor the Legionella bacteria and blow it into the building's air systems. Legionella causes two syndromes: an uncomplicated flulike illness (Pontiac fever) which clears up on its own, and a bacterial pneumonia (Legionnaires' Disease) capable of killing a person and requiring antibiotics to cure. Proper care and maintenance of swamp coolers may prevent the bacteria from growing in them and causing disease to occupants of the buildings.

Things You'll Need

• Cleaning solvents
• Replacement cooler pads
• Demineralizing solvents
• Chlorine meter
• Thermometer
• Bactericide

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Instructions

Cleaning the Swamp Cooler

• 1

  Clean the swamp cooler according to the manufacturer's recommendations. Replace the cooling pads to make sure that any bacteria colonizing the pads are disposed of.

• 2

  Disinfect the water reservoir with a chlorine bleach solution of at least 10 percent, or any other cleaning solvent guaranteed to kill bacteria.

• 3

  Use a demineralizing agent to get rid of any mineral deposits in the water reservoir. This is important since Legionella bacteria use the mineral deposits to form a biofilm, a growing colony.

Water Monitoring

• 4

  Use a chlorine meter to test the water going into the cooler's water reservoir. Make sure that the chlorine levels in the water are sufficient to prevent bacterial growth. The levels vary by water system, so consult with your town's water works on what that level should be.

• 5

  Use a thermometer to check the temperature of the water in the reservoir. According to the Maryland Department of Health and Mental Hygiene, Legionella bacteria grow best at temperatures of 77 to 108 degrees F.

• 6

  Use a bactericidal agent in the water to keep bacteria from growing.