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These Fact Sheets will tell you what you need to know and what you need to do
regarding air conditioning in the workplace.

The „What You Need To Know‟ Fact Sheet sets out the requirements for air
conditioning, the law surrounding air conditioning and risks associated with the use of
air conditioning.

The „What You Need To Do‟ Fact Sheet sets out air conditioning checklists and
troubleshooting tips.

These Fact Sheets can be used in conjunction with the UnionSafe Air Quality and Heat
Stress fact sheets.

These Fact Sheets are recommended as a guide only and are not a substitute for
professional or legal advice. If you need clarification or further advice please consult
your Union for further information.

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Air conditioning is the control of the temperature, humidity and air movement and
cleaning of air in confined space. It is sometimes referred to as environmental

Most people in Australia work best when the temperature is between 20-26 degrees;
the Australian Standard Code of Practice for factory and office work recommends the
ideal temperature range of 21 - 24 degrees.

Many workplaces use air conditioning to control temperature. While air conditioning
can make workplaces more comfortable it also has risks that should be addressed.

Under Clause 47 of the NSW OHS Regulation 2001 Hot Working Environments” the
employer must ensure that they provide adequate ventilation and air movement in
indoor workplaces. This includes air conditioning, ceiling and floor fans, etc.

The NSW OHS Regulation 2001 also says that employers must protect employees from
risks. This includes risks associated with air conditioning.

Employers must also ensure that employees are provided with proper rest breaks and
adequate fluids such as cool and clean drinking water if they are exposed to heat in
their workplace.

The Building Code of Australia 1996 requires (in clause F4.5) that all occupied rooms
must have either natural ventilation or a mechanical ventilation system (such as an
air conditioning system) that complies with AS 1668 - 1998 The use of Mechanical
Ventilation and Air Conditioning in Buildings covers air conditioning. This standard

5ff71f1e-c6ca-4189-b1ff-6c040fcb34a7.doc                                                Page 2
sets minimum requirements for air supply rates for preventing              excessive
accumulations of airborne contaminants and objectionable odours.

There are also Australia-New Zealand standards that cover air handling and water
systems in buildings. These are set out below:

   Australian/New Zealand Standard AS/NZS 3666.1:1995 – Air-handling and water
    systems of buildings - Microbial control – Part 1: Design, installation and
    commissioning, as amended.

   Australian/New Zealand Standard AS/NZS 3666.2:1995 – Air-handling and water
    systems of buildings - Microbial control – Part 2: Operation and maintenance, as

   Australian/New Zealand Standard AS/NZS 3666.3:2000 – Air-handling and water
    systems of buildings - Microbial control – Part 3: Performance-based maintenance
    of cooling water systems, as amended.

AS/NZS 3666 has a companion handbook (HB-32), which explains in plain English the
technical requirements of the standard.

Copies   of  these    standards       are   available   from   Standards   Australia

WorkCover NSW has also produced a Code of Practice, „Work in hot or cold
environments‟, the aim of which is to assist employers in deciding on appropriate
measures to eliminate or control the risks to employees who work in hot or cold
environments.    The   Code     of   Practice    can    be    downloaded    from

The NSW WorkCover Authority has issued guidelines on „indoor thermal comfort‟,
which describe optimal conditions for occupational health and safety in an office
environment. These are outlined below:

5ff71f1e-c6ca-4189-b1ff-6c040fcb34a7.doc                                               Page 3
   Optimum summer temperature range 21-24 °C

   Acceptable summer temperature range 20-26 °C

   Optimum 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 0.1-0.5 m/s (naturally ventilated), 0.1-0.2 m/s (air-

If the air conditioning system is not operating within the acceptable range, report the
problem to appropriate staff for investigation. Experience also shows that outside the
range of 20 to 26 degrees people will become uncomfortable and productivity is likely
to drop.

Therefore in the situation where only part of the air conditioning is working, the
indoor temperature should be monitored, and where the temperature exceeds 26
degrees, management should provide local control measures, such as free standing
ventilation fans or opening windows, as an interim measure until the air conditioning
is fully functioning.

If the problem is a complete failure that cannot be repaired promptly and
supplementary ventilation cannot be provided (eg windows can't be opened or fans
provided), it may be necessary to leave the area until the system is restored. If the
failure relates to temperature control only, and ventilation is still adequate, it may
be possible to continue to work in the area by taking local control measures
mentioned above.

A common sense approach when air conditioning systems are "off" is to evacuate
affected parts of the building when the working conditions become unacceptably hot,
cold or smelly.

5ff71f1e-c6ca-4189-b1ff-6c040fcb34a7.doc                                                  Page 4
There may be some other options in some situations, like working from home as a
short-term measure, but the emphasis should be on fixing up the air conditioner as
soon as possible.

If the inside temperature goes above 30 degrees Celsius and staff are feeling unwell
then measures must be taken to cool them down, and they should complete an
incident form to document the situation. In some cases, depending on how they feel,
staff may need to go home. In such a situation, where management has not been able
to implement reasonable measures to address the OHS problem, staff should not incur
any pay penalty. Contact your union for information and advice in such situations.

Note that the use of personal fans or heaters in an air conditionedarea where people
are experiencing discomfort may exacerbate the situation. It can actually make the
area hotter or colder due to interference with the automatic control system of the air
conditioning system. For example, a personal fan may cause a nearby air conditioning
thermostat to falsely sense that the room is too cool, consequently increasing the
warm air supplied to the room. This exacerbates the already uncomfortably warm

Humidity is the amount of moisture in the air. The indoor humidity to a large extent
tracks the prevailing outdoor humidity. In cool, dry winter weather heating the air
lowers the relative humidity and in Australia, because most air conditioning systems
do not humidify, dry conditions cannot be avoided.

Humidity levels cannot be measured readily, but a standard thermometer can be used
to give temperature readings. When humidity is high, tolerance of high temperatures
is reduced, due to the decreased capacity for cooling from evaporation of sweat.
Subjective feelings about humidity should be taken into account when considering
modifying or suspending work. See also UnionSafe Fact Sheet on Heat Stress.

For office work normal variations in humidity have little effect on comfort or health.
However, extremes can lead to discomfort. Cooling the air can control the high
humidity that occurs in summer. Humidity and stuffiness are often confused.
Stuffiness is usually due to poor ventilation and air circulation.

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Many workers spend long periods of time indoors in air conditioned buildings. If the air
conditioning system is not maintained a number of problems, some potentially lethal,
can occur.

OHS reps have a role to play in ensuring that risks associated with air conditioning are
identified and reduced as much as possible.

A building‟s air conditioning system is like the lungs of the building. The air
conditioning system draws in outside air, filters it, heats, cools or humidifies it,
circulates it around the building, then expels a portion of it to the outside

The quality of the air many workers breathe at work is totally dependent on the
operation of the building‟s air conditioning system. Substandard air conditioning will
lead to poor indoor air quality and irritable and potentially very sick workers.

The cost of poor air conditioning at work is enormous. Studies show that increased
sick leave and lower productivity related to poor air-conditioning, costs many millions
of dollars each year. The human costs of poor air conditioning include viral illness,
respiratory problems, and the deadly Legionnaires Disease (or Legionella).

Often the cause of breathing and nasal problems is not properly understood; therefore
the work related nature is not recognised.

There are two major areas of air conditioning that constitute a hazard in the

   Comfort, and

   Disease

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The most common complaints relating to air conditioning are about comfort. These
are that it is too hot, too cold, too stuffy, draughty or smelly. These complaints are
usually legitimate and commonly related to air conditioning features such as:

   Positioning of vents, for example, causing local draughts;

   Inappropriate number of vents, for example, inadequate air movement leading to

   Contaminated air system;

   Incorrect airflow rates leading to draughts or stuffiness.

Sometimes people who are working near windows are uncomfortable because of
uneven heating and cooling effects from the window. A solution may be found in
providing adequate shade for the window such as awnings or blinds.

Very rarely respiratory illnesses - such as Legionnaires‟ Disease, Pontiac Fever, and
Hypersensitivity Pneumonitis - can also be spread by air conditioning systems. These
illnesses are generally related to bacteria and fungi growing in cooling towers or other
parts of the system.

The control of these problems is relatively simple. The temperature of hot water must
be kept high enough to kill the bacteria. Water-containing places - such as cooling
towers - must be periodically cleaned and decontaminated. Effective maintenance
requirements for air conditioning systems are detailed in relevant Australian

In dry winter conditions some people may suffer minor complaints such as stuffy nose,
eye and skin irritation, but these cannot be avoided.

5ff71f1e-c6ca-4189-b1ff-6c040fcb34a7.doc                                                   Page 7
Legionnaires Disease is pneumonia (lung infection) caused by Legionella bacteria and
can be fatal. The Legionella bacteria can contaminate and grow in air conditioning
units and people working in or living near buildings can contract Legionnaires Disease.

Legionella bacteria occur naturally in water and can be found in rivers, lakes and
streams. The water distribution systems of large buildings have been found to contain
Legionella, along with cooling towers. Other sources may include mist machines,
humidifiers, whirlpool spas and hot springs.

People can catch the disease by breathing in very fine droplets (aerosols) of
contaminated water that contain the bacteria. Workers in the building and people
who live in the area are at risk. The disease cannot be passed from one person to
another, nor caught by drinking Legionella contaminated water.

The incubation period, or period of time between exposure to the bacteria and the
appearance of symptoms, is two to 10 days. Tiredness and weakness may be
experienced for several days, and most patients who are admitted to hospital develop
a fever often higher than 39.5°C (103°F). A severe cough producing sputum may be
the first sign of a lung infection, and gastrointestinal stomach symptoms including
diarrhoea are common. In addition, many patients experience nausea, vomiting,
stomach discomfort, headaches, muscle aches, chest pain, and shortness of breath.

If the patient has no preceding illnesses that compromise his/her immune system and
is treated with antibiotics near the onset of pneumonia, the outcome is excellent.

This Fact Sheet is recommended as a guide only and is not a substitute for
professional or legal advice. If you need clarification or further advice please consult
your Union for more information.

5ff71f1e-c6ca-4189-b1ff-6c040fcb34a7.doc                                                   Page 8
Under clause 47 of the OHS Regulation 2001 an employer must provide the
employee with adequate ventilation and air movement – that is, air conditioning or
other sources of ventilation, such as fans for indoor workplaces that may become hot.

The employer must also provide rest breaks and cool & clean drinking water if the air
conditioning system breaks down or move the employees to another location.

In the air conditioned office action to identify actual or potential hazards caused by
air conditioning can be based on:

      Complaints from staff about air quality;

      Workplace inspections;
      Air quality test reports.

All complaints should be investigated. Relevant Australian Standards on air
conditioning and National Commission exposure standards for workplace air
contaminants provide advice on the control of the occupational environment.
Guidance can also be obtained from the National Health and Medical Research Council
recommendations for air quality goals.

Under the OHS Act and Regulation employers are required to conduct risk assessments
on potential workplace hazards and to consult with their employees over OHS

5ff71f1e-c6ca-4189-b1ff-6c040fcb34a7.doc                                                 Page 9
1. Are ventilation, heating and cooling systems in place and operating well?
   □ Yes           □ No

2. Are the systems maintained, and cleaned on a regular basis?
   □ Yes          □ No

3. Is the temperature of air conditioning in normal comfort range? (Generally 20 -
   26 degrees)
   □ Yes          □ No

4. Is Humidity normally between 40-50%?
   □ Yes          □ No

5. Is sufficient volume of air through the area, average at 0.15 – 0.25 metres per
   □ Yes            □ No

6. Does the Office receive 10 litres of fresh air per person per second?
   □ Yes           □ No

7. Is air conditioning equipment is being serviced in accordance with maker’s
   instructions to avoid the spread of harmful bacteria via central air conditioning
   □ Yes            □ No

5ff71f1e-c6ca-4189-b1ff-6c040fcb34a7.doc                                               Page 10
1)       Is there ventilation or air conditioning? Is it ON? If so, and the operation appears
         faulty, or it won't switch ON, contact Building Management. Be aware that some
         systems are activated by motion sensors and may take a while to improve
         conditions, and that some facilities are fresh air ventilation only and will not be
         able to 'condition' the air. Excessive opening of windows or doors in air
         conditioned spaces can severely impair the control of temperature and humidity.

2)       In reviewing the adequacy of your air conditioning it is important that the air
         conditioning system is checked to see that it is:

          Working properly or needs maintenance, adjustment etc;

          The temperature in various places within the building (this can vary according
           to a number of things, including radiant heat, where the thermostats are
           located, etc);

          Air flow;

          Humidity; and so on.

3)       If other means of ventilation or temperature control (windows, fans, curtains,
         etc) are inadequate then review the possibility of improvements. This should be
         raised as an OHS issue during OHS consultation.

4)       Common ways to improve air conditioning:

          Regulate air conditioning for temperature and humidity;

          Avoid locating workstations directly in front of or below air conditioning

          Install deflectors on air vents to direct airflow away from people. This measure
           will prevent staff being annoyed by draughts;

          Control direct sunlight (radiant heat) with blinds, louvres and the like;

5ff71f1e-c6ca-4189-b1ff-6c040fcb34a7.doc                                                        Page 11
       Minimise draughts and thermal differences between the head and the feet
        (thermal gradients);

       Ensure adequate airflow. Feelings of stuffiness can result when airflow is low,
        and draughts result when airflow is high. An airflow rate of between 0.1 and
        0.2 metres per second is desirable.

OHS Committees and reps should ensure that employers have:

   A list of all cooling towers on site;

   Proof that all cooling towers have been registered;

   Records of the total bacterial count from all the cooling towers every month.
    (Levels of 100,000 and more are unacceptable.);

   Regular inspection, biocide dosing and maintenance records;

   Reports of full cleaning done at least yearly.

Any level of Legionella above 10% per calls for preventative action.

Talk to your members about Legionnaire's Disease and its symptoms.

Inform your union, your members and WorkCover if Legionella bacteria are found in
the workplace or if a case of workplace Legionnaires is suspected.

5ff71f1e-c6ca-4189-b1ff-6c040fcb34a7.doc                                                  Page 12
Your employer has an obligation to provide you with a safe working environment and
excessive heat can cause a number of problems such as heat stress, dizziness, nausea
and other heat related illnesses.

How to handle the problem:

   If your air conditioning fails, you should contact your supervisor/manager
    immediately and inform them of the problem.

   Take a temperature reading of your workplace and inform management of the
    situation. Continue to monitor the situation and keep management updated using
    the following “Temperature Guidelines”.

Temperature Guidelines*:

   Portable air conditioners or fans should be provided if members feel them

   If the workplace temperature reaches 30 degrees C, members should be given a
    10-minute break in each hour with cool non-alcoholic drinks provided by the

   If the workplace temperature reaches 32 degrees C, members are to be provided
    with a 20-minute break in each hour with cool non-alcoholic drinks provided by the

   If the workplace temperature reaches 35 degrees C inside the workplace then that
    workplace has to close, members should go home and no loss of pay should be

5ff71f1e-c6ca-4189-b1ff-6c040fcb34a7.doc                                                 Page 13
This Fact Sheet is recommended as a guide only and is not a substitute for
professional or legal advice. If you need clarification or further advice please consult
your Union for more information.

Also see the UnionSafe Heat Stress Fact Sheet and the WorkCover Fact Sheet: Work in
Hot Environments, which can be downloaded from the WorkCover website at:

5ff71f1e-c6ca-4189-b1ff-6c040fcb34a7.doc                                                   Page 14