Legionnaires disease has been overblown by the media and it is not
something you can contract from domestic air conditioning. The majority
of cases are caused by incorrect cooling tower maintenance. Cooling
towers are primarily used in commercial air conditioning to cool water
cooled condensers and industry to cool recirculated water. They provide
an ideal place for Legionella bacteria to grow (temps between 28 to
40°C) and the operation of the towers causes drift which aerosols the
bacteria allowing people to breathe it in. There’s probably more danger
handling potting mix than from a cooling tower because by law all towers
have to be maintained and treated with biocide. Evaporative coolers
have been suggested but not verified as potential disease transmitters.
Modern evaporative coolers also have dump valves which further lessen
the risk.
The disease does not affect everyone who comes into contact with the bacteria. The groups most at risk are:
• People over 50 years of age (predominantly males)
• Heavy smokers
• Heavy drinkers
• Diabetics
• People with chronic lung disease
• People with impaired immune systems (ie body defence mechanisms)
The disease does not affect everyone who comes into contact with the bacteria. The groups most at risk are:
• People over 50 years of age (predominantly males)
• Heavy smokers
• Heavy drinkers
• Diabetics
• People with chronic lung disease
• People with impaired immune systems (ie body defence mechanisms)