This presentation explain how air movement can be visualised inside the cleanroon in the HVAC system.

1. Air Movement
Control
VISUALISATION

2. Air Movement Control within a
Cleanroom
As part of the testing procedure to ensure that a
cleanroom is working correctly, the movement of air
within the room should be checked.
 In a non-unidirectional airflow cleanroom : Good
mixing should be demonstrated in all parts of this
type of cleanroom to ensure that contaminants will
be removed through the air extracts.
 In a unidirectional airflow cleanroom : critical
areas must be supplied with air coming directly
from the high efficiency filters.

3. Unidirectional and non
unidirectional

4. Critical areas
All areas in which any kind of sterile product
(including both drugs and equipment) must be
exposed to sterile environment and where
activities including sterilization, sterile
filling and closing take place.

5. However, problems may be
encountered because of:
 Heat rising from the machinery and disrupting
the airflow;
obstructions preventing the supply of air getting
to the critical area.
 obstructions, or the shape of machinery, turning
the unidirectional air-flow into non-
unidirectional random airflow.
 contamination being entrained into the clean
air.

6. Air movement visualisation
There are a number of methods that can be used to
visualise the flow of the air in a cleanroom.
 Streamers .
 Smoke or particle streams.
 Measurement of air velocity and direction.

7. Streamers
 The types of streamer
that are used to
visualise airflow are
usually threads or
tapes.
 A useful way of using
a streamer is to
attach it onto the end
of an anemometer.
 It can then be used to
ascertain the
direction of airflow
when the velocity is
being measured at a

8. Smoke or particle streams
 Smoke generators of the type that use glycol or
glycerine based fluids are commonly used.
 Using one of the smoke generating methods, the
air- flow in the room can be visualised and
areas found where the air movement is poor.
 The use of smokes may not be acceptable in some
cleanrooms. In this situation, water vapour can
be used as a contamination-free alternative.

10. Air velocity and direction
 A permanent record of the
airflow within the
cleanroom can be obtained
by measurement of the
velocity and
direction over a section of
the area of interest.
 Setting up a grid in the
room helps with this.
 The thread is marked at
given intervals, so that
points are available for
measuring air velocity and
direction.
two-dimensional representation of
the velocity and direction of the
unidirectional airflow