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1. Heating, Ventilation and Air-
Conditioning (HVAC)

2. Factors Contributing to Quality
Products
Raw Materials
Personnel
Procedures
Validated processes
Equipment
Premises
Environment
Packing Materials
Validated processes
Equipment
Premises
Environment
The most important!

4. HVAC
HVAC – Heating, Ventilation and Air-
conditioning system.
HVAC regulates
Room temperature
Humidity
Air quality
Air flow

5. HVAC
American Society of Heating, Refrigeration and Air
Conditioning Engineers (ASHARE) handbook – important
reference to consider when designing AHU and HVAC
Air in controlled environment shall have
A per cubic foot particle count of not more than 100000 in a size
range of 0.5 micron and larger when measured with automatic
counters, or 700 particles in a size range of 5.0 microns or larger
when measured by a manual microscopic method
A temperature of 72oF± 5o or 22oC± 3o
A maximum relative humidity of 50% and a minimum of 30 %
A positive pressure differential of 0.05 inch of water
At least 20 air changes per hour

6. Class-I
Room
(General
area)
Class-II
Room
(Support
area)
Class-III
room
(Production
and support
area)
Class-IV
room
(product
exposur
e area)
Temperature 720F±40F 700F±20F 660F±20F 660F±20F
Relative
humidity
Comfort 45%±5%
RH
45%±5%
RH
45%±5%
RH
Filtration 60%ASHRAE 95%ASHRAE SINGLE HEPA,
99.97%
DOUBLE
HEPA
Air changes Normal
ventilation
20-30/hr 40-60/hr Laminar
airflow, 90
ft/min

7. General
 Design of HVAC is dependent on required degree of air
cleanliness
 Components of HVAC
 fans,
 driers,
 filters,
 ducts, grilles, etc.

8. +
Production Room
Exhaust air treatment
Central air handling unit
Terminal air treatment
at production room level
Fresh air treatment
(make-up air)
HVAC Main subsystems

9. 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

10. Components
Components in HVAC may include, depending on need:
 Snow eliminators
 Dust eliminators
 Moisture eliminators
 Precooling coils
 Alarm systems, grilles/diffusers, etc.

11. Filter
Silencer
Terminal filter
Weather louvre Control damper
Fan
Flow rate controller
Humidifier
Heating
coil
Cooling coil
with droplet
separator
Production Room
Overview components
+
Prefilter
Exhaust Air Grille
Heater
Secondary Filter
Recirculated air
HVAC

12.  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
Components (1)
HVAC

13.  Heating unit-To heat the air to the proper temperature
 Cooling unit/ dehumidifier - To cool the air to the
required temperature or to remove moisture from the air
 Humidifier- To bring the air to the proper humidity, if too
low
 Filters - To eliminate particles of predetermined dimensions
and/or microorganisms
 Ducts -To transport the air
Components (2)
HVAC

14. Filter classes
Dust filters
Standard Aerosol
Fine
Coarse ULPA
HEPA
HVAC

15. Primary panel filter
Secondary filter
HEPA or tertiary filter
HVAC

16. Positioning of filters (1)
Filter in terminal position
AHU mounted final filter
Production Room
+
Production Room
HEPA Filter
HEPA Filter
HVAC

17.  Flow rate controller -Blocked
 Control damper-Poorly adjusted, bad pressure differential
system
 Humidifier- Bad water/steam quality/
poor drainage
 Cooling battery-No elimination of condensed water/ poor
drainage
 Filters-incorrect retention rate/damaged/badly installed
 Ducts-Inappropriate material/internal insulator leaking
Problems with components
HVAC

18. HVAC
Consider different air types, e.g.:
 Supply air
 Return air (recirculated air)
 Fresh air (make-up air)
 Exhaust air
Concepts of air delivery to production areas:
 Recirculation systems
 Full fresh-air systems

19. +
Production Room
Exhaust
air
Return air
(recirculated)
Fresh air
(make-up air)
Supply
air
Air types
HVAC

20. Recirculation systems
 There should be no risk of contamination and cross-
contamination 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

21. Ventilation with recirculated air + make-up air
Central Air-Handling Unit
Return air
Exhaust Unit
HVAC

22. 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

23. Ventilation with 100% fresh air (no air recirculation)
W
Washer (optional)
Central Air-Handling Unit
Production Rooms
Exhaust Unit
HVAC

24. © 2009 Bahill
24
2/27/2023

25. © 2009 Bahill
25
2/27/2023