This document discusses HVAC systems for cleanrooms. It explains that HVAC systems in cleanrooms must tightly control temperature, humidity, pressure and ventilation to strict standards in order to minimize particles and ensure sterile environments. It outlines the functions of HVAC including air filtration, pressure control, humidity control and temperature regulation. The document also compares US federal cleanroom standards to European standards and describes how cleanroom HVAC systems differ from standard HVAC through increased air changes, high-efficiency filters, laminar airflow and room pressurization.

1. HVAC Basics
Saptarshi Das
B.Pharm,4th year
Bengal School Of Technology
HVAC – Heating, Ventilation, Air-conditioning
UNDER SUPERVISION OF Dr. JAYANTA CHATTOPADHYAY
PROFESSOR OF BENGAL SCHOOL OF TECHNOLOGY

2. HVAC
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HVAC – Heating, Ventilation, Air-conditioning
Temperature
Humidity
Pressure
Ventilation
68°F (20°C) and 75°F (25°C)
30% relative humidity (RH) and 60% RH
A slightly positive pressure to reduce
outside air infiltration.
Rooms typically have several
complete air changes per hour

3. What can HVAC do?
• HVAC system performs four basic functions:
1. Control airborne particles, dust and micro-organisms – Thru
air filtration using high efficiency particulate air (HEPA)
filters.
2. Maintain room pressure (delta P) – Areas that must
remain“cleaner” than surrounding areas must be kept under a
“positive” pressurization, meaning that air flow must be from
the “cleaner” area towards the adjoining space (through doors
or other openings) to reduce the chance of airborne
contamination.
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4. 3. Maintain space moisture (Relative Humidity) Humidity is
controlled by cooling air to dew point temperatures or by
using desiccant dehumidifiers. Humidity can affect the
efficacy and stability of drugs and is sometimes important to
effectively mould the tablets.
4. Maintain space temperature - Temperature can affect
production directly or indirectly by fostering the growth of
microbial contaminants on workers.
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5. U.S Federal standard 209E
1. Class 100 (M 3.5) is the area where the particle count must
not exceed a total of 100 particles per cubic foot (3,530
particles per m3) of a size 0.5 microns and larger.
2. Class 10,000 (M 5.5) is the area where the particle count must
not exceed a total of 10,000 particles per cubic foot (353,000
particles per m3 ) of a size 0.5 microns and larger or 70
particles per cubic foot (2,470 particles per m3), of a size 5.0
micronsand larger.
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6. 3. Class 100,000 (M 6.5) is the area where the particle count
must not exceed a total of 100,000 particles per cubic foot
(3,530,000 particles per m3) of a size 0.5 micron and larger
or 700 particles per cubic foot (24,700 particles per m3 ) of
a size 5.0 micronsand larger.
4. All pharmaceutical facilities belong to one or other class of
cleanroom. General acceptance is:
• Tabletting facilities - Class 100,000
• Topical & oral liquids - Class 10,000
• Injectables class - Class 100.
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7. EUROPEAN COMMUNITY GUIDELINES
• European Community defines cleanrooms in alpha Grades A,
B, C and D. The classification is given on two different
conditions: 1) “At-Rest” and 2) ‘In-Operation”
• “At –Rest” - ‘state of cleanrooms is the condition where the
production equipment is installed and operating but without
any operating personnel.
• “In- Operation” - state of cleanrooms is the condition where
the installation is functioning in the defined operating mode
with the specified number of personnel working.
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8. Comparison of US Federal standard 209E v/s EEC
• Class 100 is equivalent to (Grades A and B)
• Class 10,000 is equivalent to (Grade C)
• Class 100,000 is equivalent to (Grade D)
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9. Heating
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10. Cooling
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11. AHU
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Damper
Heating/Cooling Coil
Fan
Sensor
Filter
What’s in an AHU?

12. How do Cleanrooms HVAC different from a normal comfort air
conditioned space?
1. Increased Air Supply: Whereas comfort air conditioning
would require about 2-10 air changes/hr, a typical
cleanroom, say Class 10,000, would require 50 - 100 air
changes. This additional air supply helps, to dilute the
contaminants to an acceptable concentration.
2. High Efficiency Filters: The use of HEPA filters having filtration
efficiency of 99.97% down to 0.3 microns is another
distinguishing feature of cleanrooms.
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13. 3. Terminal Filtration and Air Flow pattern: Not only
are high efficiency filters used, but a laminar flow is
sought.
4. Room Pressurization: With the increased fresh air
intake, cleanrooms are pressurized in gradients.
This is important to keep external particulates out
of clean spaces.
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14. Where HVAC can use ?
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Mechanical Room: Boilers, chillers, pumps, heat exchangers…
Air Handling Units (AHUs): heat, cool, humidify, dehumidify, ventilate, filter and
distribute the air.
Room Controls: thermostats and Variable Air Volume (VAV) boxes

15. Thanks!
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