Specimen engineering designs for cooling towers and condensers

Where to sample in an installation - general guide

(Refer also to guidance from L8 Legionnaires' Disease Health and Safety Executive paper [1]. Other member states might have their own versions of such guides.)

Cooling systems including cooling towers and evaporative condensers

Typical cooling tower

Red = return to cooling tower

Sampling cooling systems

• Ideally sample from somewhere on the return to cooling tower
• Neutralise biocides where possible, for more detail see [2]

Outbreak investigation samples from cooling systems should be taken:

• From the warmest point
• Possibly from the pond (furthest away from fresh water inlet ball valve if possible)
• Supply water / Make up water
• Foam (slime) from pack, and other components
• Biofilm
• Any others suggested by the risk assessment