Download 2. - HVAC Education Australia

(1-100 Microns) or Microbes.
than the virus itself.
The filter then needs to remove a much larger particle
Test Dust No.2 - Particles in 3-10 Micron range are c'llected (dirt and droplet particles),
however, it is no good for viruses (say 0.03 to 0.8 Microns).
Some examples of viral infections are Smallpox, Chickenpox, Measles, Mumps, Influenza
and the common cold. The common cold are produced during 'sneezing, the droplet
nuclear are 4 Micron approx.
The better the filter fficiency, the better for the occupiers.
For correct maintenance and installation edge and face sealing is critical. Always seal on
the "air on" side, even if an access panel is required.- Ensure that all moisture is
eradicated from filters and ductwork as bacteria, moulds, fungus and other micro
organisms rely on moisture for their survival and growth. They are aquatic life forms.
Humidifiers
More prevalent overseas, not so much in our climate. However, when used in industry,
eg. printing works, textile factories and woodworking shops there is an abundance of food
for Microbes (cellulose material).
Steam is preferred and "clean steam" (free of chemicals is best).
Conditioner and
duotwork condensate trapping - access for ease of cleaning - chemical disinfection to be
carried out after manual clean if slimes, etc. present.
Water type, whilst more economical and simpler to install for smaller systems, etc.
computer rooms, have problems of solids, chemicals and other matter remaining. The
end of main seasonal usage (ie. Winter) these systems require vigorous and intensive
service and clean up.
WATER COOLING SYSTEMS
The excess heat energy extracted from a building by an air conditioning system is
released into the atmosphere via a cooling tower. Because of the temperature of the
water and the presence of sludge, algae and so on, the water cooling system may aid the
proliferation of Legionella and other bacteria.
The aerosol drift from a contaminated tower may cause an infection in nearby susceptible
people. The correct operation and regular routine maintenance including cleaning are
important to ensure the desired performance and acceptable hygienic conditions of all
components of the air conditioning system.
Water Treatment
A water treatment program is essential for a condenser water cooling system to inhibit
corrosion, the build-up of scale and the development of any microbial contamination.
Corrosion and scale development can cause fouling of the condenser tubes and the