Legionnaires’ disease is a potentially fatal pneumonia caused by legionella bacteria. It is the most serious form of a group of diseases known as legionellosis. Other similar (but usually less serious) conditions include Pontiac fever and Lochgoilhead fever.

Legionella bacteria are common in natural water courses such as rivers and ponds. Since legionella are widespread in the environment, they may contaminate and grow in other water systems such as cooling towers and hot and cold water services.

They survive low temperatures and thrive at temperatures between 20-45°C if the conditions are right, e.g. if a supply of nutrients is present such as rust, sludge, scale, algae and other bacteria. They are killed by higher temperatures.

Cooling towers, evaporative condensers and hot and cold water systems have been associated with outbreaks.

Keeping the water in a cooling tower system clean will not only control legionella, but also lead to other advantages. By reducing scale and fouling, you are also ensuring that the cooling process is operating efficiently. Scaling reduces the effectiveness of biocide treatment and fouling can lead to loss of plant performance.

Benefits of Clean Water

  1. Reduced energy consumption - as little as a 1mm layer of dirt, scale, or biological deposits on heat transfer surfaces results in a loss of cooling tower efficiency, increasing energy costs.
  2. Improved chemical performance - dirty water requires more chemicals to treat than clean water because a build-up of solid contaminants provides a buffer that reduces the effects of treatment chemicals. Additional chemicals are then necessary.
  3. Lower maintenance cost - frequently draining a tower and cleaning sediment increases labour requirements, and results in added costs to replace lost water in the system and provide additional chemicals.
  4. Improved productivity and less downtime - fouling a cooling system slows production because machines cannot run efficiently. A fouled heat exchanger could take a system down for an extended period of time until repairs are complete, resulting in less production per day and lost profits.
  5. Control of biological growth - legionella, bacteria that thrives in improperly maintained cooling tower environments, is particularly important to control because it poses significant health risks.

Filtration - for more information just use our contact form

  1. A 200 ton cooling tower will draw in over 300kgs debris during a typical cooling season.
  2. The tower basin or remote sump provides a perfect environment for unwanted matter to settle and accumulate whilst the wet and warm conditions of the basin or remote sump encourage bacteria growth.
  3. Chemical water treatment does control the effects of these microbial organisms, but on its own does not serve to eliminate the habitat that promotes the proliferation of organisms.
  4. Using an air intake filter system does not replace chemical treatment but chemicals cannot reduce particle build-up.
  5. Insects, seed, dust and other airborne particulate will ultimately provide the nutrients for bacteriological growth.
  6. The tower basin or remote sump provides a perfect environment for unwanted matter to settle and accumulate whilst the wet and warm conditions of the basin or remote sump encourage bacteria growth.

Solution - a RABScreen - would you like to know more? Just use our contact form

  1. Reduce the build-up of contamination, the breeding grounds for microbial organisms, by fitting an air intake protection screen
  2. The RABScreen air intake protection screen will protect the air inlets and remove a large percentage of airborne debris being drawn into the tower.
  3. And when they are dirty simply wash, vacuum or brush clean. A truly cost effective solution.

Technical information provided by BAC. To see the full article please go to http://www.baltimoreaircoil.com/english/resource-library/file/652

RABScreen filters can be used wherever you have air movement and, because they are weather resistant, are suitable for both internal and external applications.

Just call or email to see how we can save start saving you money.


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