Legionella is mostly associated with hot and cold water systems, but any equipment that holds warm water and creates a spray or mist deserves a second look. Air handling and humidification equipment is one area people tend to forget.
Systems worth asking about
- Humidifiers that spray or evaporate water into the air, particularly where water is stored and recirculated.
- Air handling units with water-based humidification or condensate trays.
- Cooling systems that use water, such as evaporative coolers.
- Misting systems in shops, terraces and production areas. See our guide on water features and misting systems.
Many ordinary split air conditioning units do not store water in the way these systems do, so the right answer depends on what you have.
Good practice
- List every water-using system in the building, including plant on the roof or in plant rooms.
- Ask your supplier or installer for maintenance and cleaning instructions, and follow them.
- Keep water fresh. Avoid stagnation and clean on a set routine.
- Include these systems in your legionella risk assessment and logbook.
- Use competent people for servicing, and keep records of what was done.
Your duties
Under the Safety, Health and Welfare at Work Act 2005, employers must manage risks to the health of employees and others affected by their activities, which includes risks from water systems. The HPSC National Guidelines for the Control of Legionellosis in Ireland (2009) give practical guidance.
Not sure what you have?
A site visit is the quickest way to find out which systems matter in your building.
Talk to Safer Solutions
A legionella risk assessment reviews your whole water system and gives you practical, prioritised recommendations. Where sampling is needed, samples go to an independent accredited laboratory. Call 086 275 9728 or email info@safersolutions.ie for a friendly chat. Browse our fire and legionella guides.