INDOOR THERMAL COMFORT & VENTILATION

Maintaining a comfortable indoor climate is important for the health and comfort of workers, as well as ensuring optimum work performance. These guidelines provide some information about the optimum conditions and what can be done locally to improve comfort levels in relatively warm or cool indoor areas.

This information is supplementary to the Air Conditioning Policy published by the Campus Infrastructure Services.

Optimal conditions

The optimal conditions for indoor work environments are outlined below.

  • Temperature range 20-26 degrees Celsius (depending on the time of year)
  • Humidity range 40-60%
  • Minimum recommended fresh air rate 10 Litres per second (L/s) per person or 10 L/s per 10 m2 for mechanical ventilation systems
  • Optimum air movement 0.1-0.2 m/s (air-conditioned space).

Typically staff and student concerns about indoor thermal comfort occur in areas that are poorly ventilated and/or inadequately shaded from sunlight. Individual thermal comfort can also be affected by physical exertion, crowded working areas and some medical conditions.

Thermal comfort is determined by subjective judgment, and even in optimal conditions some individuals may experience discomfort.

Risks

When conditions differ from those listed above, productivity and efficiency are likely to be adversely affected. Lowered concentration due to discomfort can lead to an increased risk of accidents.

  • Hot and humid conditions can lead to dehydration.
  • Insufficient ventilation (supply of fresh air) can result in a build up of carbon dioxide levels that can result in occupants feeling tired and complaining of stuffiness.
  • Too much ventilation, e.g. air movement faster than 0.2 m/s, may result in some staff complaining of the cold due to noticeable draughts.
  • Low humidity can cause dryness of the eyes, nose and throat.
  • High humidity results in rapid fatigue.

Risk controls for hot & humid conditions

  • Use blinds and curtains to minimise sunlight penetration into the workplace.
  • Optimise air movement by using a fan.
  • Wear appropriate clothing.
  • Drink plenty of cool water at regular intervals.
  • Negotiate with local management for staff and students to take breaks in cooler and/or less humid areas or transfer some work to cooler and/or less humid areas.
  • Careful consideration must be given to the organisation of physically demanding work and work that involves safety-critical tasks.

Risk controls for cooler conditions

  • Wear appropriate clothing such as wool or other insulating clothing, but ensure it is not too bulky to interfere with work activities.
  • Move around the work area and engage in active tasks as physical activity naturally generates bodily warmth
  • Use effective room heaters in non air-conditioned areas - see the Guidelines for Room Heaters.

Reporting problems

If you have concerns about thermal comfort or ventillation, discuss the issue with your supervisor.

In air-conditioned areas, report operational problems to Campus Infrastructure Services via Campus Assist Online.

References

  • WorkCover NSW - Code of Practice - Managing the Work Environment and Facilities
  • AS1668.2 - The use of ventilation and air-conditioning in buildings