6. Examples of improving ventilation

A changing room with poor ventilation

A changing room in a production facility had no windows that opened and no mechanical ventilation. Workers reported to management that the room felt stuffy. Different staff used the changing room frequently, especially at the beginning and end of shifts.

Changes to achieve adequate ventilation

  • The manager found that the room did feel stuffy, indicating that the ventilation was not good enough. They needed to get fresh air into the room.
  • The trickle vents at the top of each window had been closed so these were opened to provide background fresh air
  • The business also installed an extractor fan to help reduce excess humidity, heat and odour

An office with mechanical ventilation

An office space had a recirculating mechanical ventilation system that provided heating and cooling. It was set on 80:20 recirculating to fresh air intake.

The business didn't know how to alter the settings to allow for more fresh air or if the system was already delivering a suitable amount of fresh air to the office workers.

Changes to achieve adequate ventilation

  • The business needed a competent ventilation engineer to help them
  • A ventilation engineer checked the system performance and found it had deteriorated as the business hadn't maintained it for a while
  • The engineer did some remedial work and checked the system was working as it was designed
  • The business set up a maintenance schedule for the system so it could be regularly serviced

Meeting rooms with carbon dioxide (CO2) monitors

A company had CO2 monitors mounted on the walls of their meeting rooms. The readings could give a rough indication of whether ventilation is sufficient to comply with health and safety law.

The business had installed the monitors as workers were concerned that air in the meeting rooms felt warm and stuffy at certain times. Managers were not sure when poor ventilation was a problem.

They found that levels of CO2 indicated poor ventilation after 2.5 hours and they remained high for a long period of time, even after the room had been vacated. They noted that windows had been painted shut, though ventilation bricks were in place.

Changes to achieve adequate ventilation

  • The business scheduled work to reopen windows that had been painted over
  • In the interim, managers explained that meetings should be kept to a maximum of 2 hours and the door should be kept open between use
  • They continued to monitor CO2 levels to assess whether the level of ventilation was acceptable until the windows could be opened
  • Once the windows were reopened, CO2 levels indicated that ventilation was adequate

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