1. No category

Supplementary Training Modules on
Good Manufacturing Practice
Heating, Ventilation and AirConditioning (HVAC)
Part 2:
HVAC systems and components
Section 7
HVAC
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Slide 1 of 29
May 2006
HVAC
Objectives
In the following slides, we will study the components of airhandling systems in order to:
HVAC
1.
Become familiar with the components
2.
Know their functions
3.
Become aware of possible problems
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Slide 2 of 29
May 2006
HVAC
General
 Design of HVAC is dependent on required degree of air
cleanliness
 Suitable components should be selected including:
–
–
–
–
fans,
driers,
filters,
ducts, grilles, etc.
7.
HVAC
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Slide 3 of 29
May 2006
HVAC Main subsystems
Exhaust air treatment
Fresh air treatment
(make-up air)
+
Terminal air treatment
at production room level
Production Room
Central air handling unit
HVAC
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Slide 4 of 29
May 2006
HVAC
Components
Components in HVAC may include, depending on need:
 Filters
 Fans
– no fan failure; including supply air fans, return air fans,
exhaust air fan, dust extract system fans
 Driers
– Drying of air with chemical driers, e.g. rotating desiccant
wheel
 Frost coils for preheating air
HVAC
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Slide 5 of 29
May 2006
7.1.1 – 7.1.7
HVAC
Components
Components in HVAC may include, depending on need:
 Snow eliminators
 Dust eliminators
 Moisture eliminators
 Precooling coils
 Alarm systems, grilles/diffusers, etc.
HVAC
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Slide 6 of 29
May 2006
7.1.1 – 7.1.7
HVAC
Overview components
Exhaust Air Grille
Silencer
Weather louvre
Flow rate controller
Fan
Control damper
+
Humidifier
Prefilter
Cooling coil
with droplet
separator
Secondary Filter
Heating
coil
Recirculated air
HVAC
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Slide 7 of 29
May 2006
Filter
Heater
Terminal filter
Production Room
HVAC
Components (1)
 Weather louvre
 To prevent insects, leaves, dirt and rain
from entering
 Silencer
 To reduce noise caused by air
circulation
 Flow rate controller  Automated adjustment of volume of air
(night and day, pressure control)
 Control damper
 Fixed adjustment of volume of air
HVAC
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Slide 8 of 29
May 2006
HVAC
Components (2)
 Heating unit
 Cooling unit/
dehumidifier
 Humidifier
 Filters
 Ducts
HVAC
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Slide 9 of 29
May 2006
 To heat the air to the proper
temperature
 To cool the air to the required
temperature or to remove moisture
from the air
 To bring the air to the proper humidity,
if too low
 To eliminate particles of predetermined
dimensions and/or microorganisms
 To transport the air
HVAC
Air-handling unit
Control damper for airflow
Humid room air
Adsorber wheel
AHU with fan Variable
Speed Controller
Regeneration air
Humid room air
Air heater
De-humidification
HVAC
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Slide 10 of 29
Dry air
May 2006
Filter Pressure
Gauges
HVAC
Humidifier
HVAC
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Slide 11 of 29
Silencer
May 2006
Heating and
cooling units
HVAC
Filter classes
Dust filters
Standard
Coarse
Fine
Dp > 10 µ m
10 µ m > Dp > 1 µ m
G1 - G4
F5 - F9
EN 779 Standard
HVAC
Aerosol
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Slide 12 of 29
May 2006
HEPA
ULPA
Dp < 1 µ m
H 11 - 13
U 14- 17
EN 1822 Standard
HVAC
HEPA or tertiary filter
Primary panel filter
Secondary filter
HVAC
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Slide 13 of 29
May 2006
HVAC
Classification of filters according to their efficiency
HVAC
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F9
Average Efficiency
Integral Value
Retention in Penetration
%
85
0.15
H11
95
0.05
H12
99.5
5x10
H13
99.95
5x10
U14
99.995
5x10
Slide 14 of 29
May 2006
Peak Arrestance
Local Value
Efficiency
Penetration
-3
97.5
25x10
-3
-4
99.75
25x10
-4
-5
99.975
25x10
-5
HVAC
Positioning of filters (1)
AHU mounted final filter
Filter in terminal position
HEPA Filter
+
Production Room
HEPA Filter
HVAC
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Slide 15 of 29
May 2006
Production Room
HVAC
Positioning of filters (2)
Prefilter
AHU
Main filter
Ceiling
exhausts
2
1
Low level exhausts
HVAC
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Slide 16 of 29
May 2006
3
HVAC
Positioning of filters (3)
Final filter
AHU
Prefilter
1
HVAC
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Slide 17 of 29
2
May 2006
HVAC
1
2
3
4
Swirl Type air diffusors with
terminal filters
1
2
3
4
HVAC
Filter
Tightening frame
Register outlet
Screw fixation for register
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Slide 18 of 29
May 2006
HVAC
High induction
office type diffusor
(avoid)
HVAC
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Slide 19 of 29
May 2006
Low induction
swirl diffusor
(preferred)
HVAC
Regulation of room pressure – pressure differentials concept
Room pressure
gauges
Room pressure indication panel
HVAC
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Slide 20 of 29
May 2006
HVAC
Problems with components
 Flow rate controller
 Control damper
 Humidifier
 Cooling battery
 Filters
 Ducts
HVAC
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Slide 21 of 29
May 2006
 Blocked
 Poorly adjusted, bad pressure
differential system
 Bad water/steam quality/
poor drainage
 No elimination of condensed water/
poor drainage
 Incorrect retention rate/damaged/badly
installed
 Inappropriate material/internal insulator
leaking
HVAC
In the next slides
Consider different air types, e.g.:
 Supply air
 Return air (recirculated air)
 Fresh air (make-up air)
 Exhaust air
And: Concepts of air delivery to production areas:
 Recirculation systems
 Full fresh-air systems
HVAC
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Slide 22 of 29
May 2006
HVAC
Air types
Fresh air
(make-up air)
Supply
air
+
Production Room
Return air
(recirculated)
HVAC
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Slide 23 of 29
May 2006
Exhaust
air
HVAC
Recirculation systems
 There should be no risk of contamination and crosscontamination when air is recirculated
 Normally, HEPA filters (EN1822 H13) needed in supply air
stream
– Not required in single product facility with no risk of cross-contamination
– Not required where no dust generation (e.g. secondary packaging)
 HEPA filters placed in AHU or terminally
 Dust from highly toxic processes should not be recirculated
7.2.1 – 7.2.6
HVAC
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Slide 24 of 29
May 2006
HVAC
Ventilation with recirculated air + make-up air
Exhaust Unit
Central Air-Handling Unit
Return air
HVAC
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Slide 25 of 29
May 2006
HVAC
HVAC
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Slide 26 of 29
May 2006
HVAC
Full fresh-air systems
 100% fresh air - normally where toxic products are processed,
and recirculation not recommended
 No contamination from fresh air – sufficient filtration needed
 Degree of filtration on exhaust dependent on exhaust air
contaminants and environment regulations
 Energy-recovery wheels
– Should not be source of contamination
– Relative pressure between supply and exhaust air
7.3.1 – 7.3.3
HVAC
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Slide 27 of 29
May 2006
HVAC
Ventilation with 100% fresh air (no air recirculation)
Washer (optional)
Exhaust Unit
W
Central Air-Handling Unit
Production Rooms
HVAC
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Slide 28 of 29
May 2006
HVAC
HVAC
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Slide 29 of 29
May 2006