Bacteria in Closed Heating & Chilled Water Systems
With the increasing complexity of building services installations in modern, highly serviced offices, commercial buildings and other work spaces, the need to manage and control bacteria in closed heating and chilled water systems is becoming ever more important.
Bacteria in closed heating & chilled water systems
Here we consider the main problems caused by bacteria in closed heating and chilled water systems, we look at how to carry our simple water tests to identify the contaminating bacteria, and the types of bacteria that are commonly found to contaminate closed systems.
The many problems associated with the bacterial contamination of open circuit pipework systems, especially open evaporative cooling water systems and cooling towers is now well recognised, particularly where waterborne pathogens such as Legionella bacteria can present safety critical issues.
Approved codes of practice, detailed guidance notes and tried and tested management and control procedures now exist for dealing effectively with microbial contamination in such open circuit systems.
However, the issues associated with the growth and proliferation of bacteria in closed heating and chilled water systems is still less understood although there are a number of key guides now available to assist building services engineers, water treatment companies and facilities management specialists in this important area including:
What problems are caused by bacteria in closed systems?
The presence of unwanted bacteria in closed heating and chilled systems can cause a number of potentially serious problems including:
How to test for closed system bacterial contamination
Typical bacterial contamination of closed heating and chilled water systems can include pseudomonas, sulphate reducing bacteria, nitrite reducing bacteria and other slime forming bacteria.
Avoiding contamination of closed circuit water systems should be your primary objective, however if you suspect problematic microbial contamination has occurred then there are a number of simple tests you can perform on a water sample taken from the system to confirm this. The tests include:
Types of bacteria commonly found to contaminate closed heating & chilled water systems
| Bacteria | Typical Characteristics | Temp | pH |
|---|---|---|---|
| Pseudomonas Bacteria | Pseudomonas Aeruginosa – slime forming aerobic bacteria | 20 – 40 °C | 4 – 8 |
| Sulphate Reducing Bacteria (SRB) | Desulfovibrio – anaerobic bacteria that forms hydrogen sulphide | 20 – 40 °C | 4 – 8 |
| Sulphur Bacteria | Thiobaciullus – sulphuric acid forming aerobic bacteria | 20 – 40 °C | 1 – 6 |
| Iron Bacteria | Leptothrix – slime forming aerobic bacteria | 20 – 40 °C | 7.4 – 9.5 |
Expert closed system engineering solutions
Water Treatment Services are a leading independent UK water management company offering expert water management solutions including the management of closed heating and chilled water systems, water disinfection, cleaning and chlorination of water systems, pre-commission cleaning, boiler and cooling water treatment, energy efficiency and engineering support services..
With offices in London serving the South and South East England, Manchester (North West), Birmingham (Midlands), Bristol (South East England and Wales), Leeds (North and North East) and Glasgow (Scotland), supported by regional teams of specially trained engineers, site service specialists and technical experts we can offer water management treatment services including the management of closed heating and chilled water systems across the whole of the UK.
Contact us today to learn how our water management solutions can ensure your building services installations are maintained to achieve optimum performance… contact us →
Further reading…
More information about bacteria in closed heating and chilled water systems… here →
