Air Solution Company – Helping to Maintain Healthy Evaporative Cooling Systems

May 23, 2022 0 Comments

It is a bacterial infection that is characterized by pneumonia. According to the Center for Disease Control (CDC), legionnaire’s disease is caused by bacteria known as Legionella pneumophila. There are at least 43 species of legionella however, it is the Legionella pneumophila strain that causes over 90% of legionnaire disease deaths.

In the United States, it is estimated that as many as 18,000 cases occur each year. Death results in 5 – 15% of the cases.

Legionella are commonly found in low concentrations in both natural and unnatural (man-made) aquatic environments. Within unnatural environments, where water is used in an evaporative heat exchange process, warm temperatures combined with poorly treated cooling water can create an environment ideal for proliferation of this deadly bacteria.

Because cooling towers, evaporative condensers and chillers are highly efficient at drawing large volumes of air to support the legionella preventie evaporative cooling process, airborne organic material such as leaves, insects, pollen, birds, cotton wood and other debris is usually drawn into the water system and if not maintained can accumulate, decompose and contribute to system fouling and microbial growth including legionella pneumophila.

Ideal conditions for legionella proliferation include water temperatures between 77 – 108 degrees Fahrenheit (25 – 42 degrees Centigrade), presence of organic debris, sediment, scale, stagnant conditions and presence of amoebae. Legionella naturally preys on amoebae and incidentally prey on phagocytic cells (part of human immune system) when inhaled thus leading to Legionnaire’s Disease. The legionella bacteria is transmitted by aerosol (mist) from devices such as cooling towers showers and faucets and aspiration of contaminated water. Person-to-Person transmission does not occur.