Industrial Ventilation
- A major control measure
Dr. AA, UTM
Part 1 - Introduction
What Is Industrial Ventilation?
 Environmental engineer’s view:
The design and application of equipment for
providing the necessary conditions for
maintaining the efficiency, health and safety of
the workers
 Industrial hygienist’s view:
The control of emissions and the control of
exposures
 Mechanical engineer’s view:
The control of the environment with air flow. This
can be achieved by replacement of contaminated
air with clean air
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Why Industrial Ventilation?
 To maintain an adequate oxygen supply in the
work area.
 To control hazardous concentrations of toxic
materials in the air.
 To remove any undesirable odors from a given
area.
 To control temperature and humidity.
 To remove undesirable contaminants at their
source before they enter the work place air.
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Types Of Industrial Ventilation
Systems
1. Supply systems
 To create a comfortable environment in the plant i.E.
The HVAC system
 To replace air exhausted from the plant i.E. The
replacement system
2. Exhaust Systems
 An exhaust ventilation system removes the air and
airborne contaminants from the work place air
 The exhaust system may exhaust the entire work area,
or it may be placed at the source to remove the
contaminant at its source itself
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Supply Systems
Components
 Air inlet section
 Filters
 Heating and/or cooling equipment
 Fan
 Ducts
 Register/grills for distributing the air within the work
space
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Exhaust Systems
Types of exhaust systems:
 General exhaust system
 Local exhaust system
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General Exhaust Systems
 Application
• Used for heat control in an area by introducing large
quantities of air in the area. The air may be tempered
and recycled.
• Used for removal of contaminants generated in an area
by mixing enough outdoor air with the contaminant so
that the average concentration is reduced to a safe
level.
 Two Types
• Natural Ventilation: uses wind or thermally induced
convection to induce air flow.
• Mechanical Ventilation: Uses fan (with or without duct)
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Local Exhaust Ventilation (LEV)
 The objective of a local exhaust system is to remove
the contaminant as it is generated at the source
itself.

Advantages:
• More effective as compared to a general exhaust system.
Remove contaminant before it has a chance to spread.
• The smaller exhaust flow rate results in low heating costs
compared to the high flow rate required for a general
exhaust system.
• The smaller flow rates lead to lower costs for air cleaning
 Components:
• Hood
• The duct system including the exhaust stack and/or
recirculation duct
• Air cleaning device
• Fan, which serves as an air moving device
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Local Exhaust Ventilation
Exhaust
outlet
Ducting
Hood or exhaust
inlet
Fan and motor
Filter or purifying
system
Ducting
What is the difference between Exhaust and
Supply systems?
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End of Part 1