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Air-conditioner installation

Issued: 24 November 2009
Last Updated: 24 November 2009


The purpose of this safety alert is to:

  • inform workers installing air-conditioning units about the risk of working on pressurised plant
  • provide guidance on ways to control the risks of working on pressurised plant and ensure a safe system of work is followed.


Inspectors from Workplace Health and Safety Queensland have recently undertaken investigations into two incidents involving workers installing air-conditioning units.

In the first incident, the worker appears to have been struck in the chest by the end of a pipe from an air handling unit's chilled water coil, which was pressurised after manufacture, causing him to fall over three metres. He died as a result of injuries sustained in the fall. The worker was using a pipe cutter to remove the end of the coil in preparation to install the unit when the incident occurred.

In the second incident, a worker using a pipe cutter to remove the end of the pipe was unaware that days earlier another worker had pressurised the pipe. The end of the pipe struck him in the eye fracturing his eye socket. The incident could have been worse if the worker hadn't been wearing his safety glasses which appear to have taken the brunt of the force from the projectile.

Recommended control or prevention measures


Manufacturers of air-conditioning units should de-pressurise coils:

  • after testing
  • and prior to supply.

Administrative controls

  • Manufacturers must provide clear and adequate:
    • warnings on all air-conditioning units about the possibility that the unit's coil could be under pressure
    • instructions on the safe use and installation of air-conditioning units.
  • All installers must be given instruction, training and information about the safe use, installation and maintenance of air-conditioning units.
  • All installers and companies working in the industry must implement safe systems of work when working with air-conditioning units and associated plant.
  • Implement controls to reduce workers' exposure to plant under pressure and the associated risk of serious bodily injury and/or death.