Evaporative cooling systems

This page explains how the risks of legionella developing in evaporative cooling systems can be controlled.

The cooling system may consist of:

a cooling tower
an evaporative condenser or other cooling element
the re circulating pipe work
the heat exchanger
pumps
ancillary items such as supply tanks and pre-treatment equipment

If you have a cooling tower or evaporative condenser, you should put in place appropriate measures to prevent or control the risk of legionella as described in Legionnaires' disease: The control of legionella bacteria in water systems.

If you have another type of cooling system, you need to put other measures in place to prevent or control the risk from legionella and these must be as equally effective.

Part 1 of Legionnaires' disease: Technical guidance covers:

types of evaporative cooling equipment
m anagement of evaporative cooling systems (design and construction, commissioning, management of cooling systems, operation, maintenance)
requirements of a cooling water treatment programme (microbial, corrosion, scale and fouling control, physical cleanliness, conventional chemical water treatment, biocides, alternative treatment techniques)
inspection, cleaning and disinfection (cleaning, disinfecting and inspecting a cooling system)
monitoring water quality (general monitoring and analysis, monitoring for legionella)