HVAC for clean rooms 120217

4

By

Review of Design Methods to Control

Internal Environment in Cleanrooms

Professor Moustafa M. ElsayedConsultant, EGEC

[email protected]

1

4

By

Review of Design Methods to Control

Internal Environment in Cleanrooms

Professor Moustafa M. Elsayed

Consultant, EGEC

[email protected]

5

Outline

Introduction

Standards & Classifications

Contamination

Testing

Types of Clean Areas

HVAC System Design

Air Flow Pattern

Air Filtration

Design Parameters

Air Distribution

T & RH Control

Pressurization Control

Validation Tests

HVAC System Cost

Other Design Consideration

Anterooms

6

Introduction

Definition of a cleanroom.

First use of cleanrooms: NASA (so-called white room).

Objectives of cleanrooms operation are:

To maximize productivity

To reduce rejection

To achieve unbiased experimentation

To prevent contamination

To increase product shelf life 7

Table 1 Typical Cleanroom Applications for Various

Segments of Users

ApplicationsUserGroup

Wafer Fabrication, Microprocessor, Large Wafer Sizes, IC, Hybrids, Flat Panel Displays

SemiconductorsA

Computer, Compact Disc, Printed Circuits, Disk Drivers, Other Magnetic Media, Sensor/Relays, Computer Peripherals

ElectronicsB

Liquid Drug Filling, Biological Research, Botanical, Pharmaceutical Preparations, Biomedical, Biotechnology

PharmaceuticalC

Relative Share of Cleanrooms Users

2

8

ApplicationsUserGroup

Defense Contractors, Satellites, Space Craft Inst., Aircraft Instruments

AerospaceD

Aseptic food Process, Beverage Filling, Cereal Manufacturing, Dairy Pasteurization, Food Preparation, Agriculture

FoodE

Surgical Transplants, Artificial Limb Prod., Surgical Suites, I.V. Drug Injections, Blood Banks

MedicalF

Automotive, Laser/Optics, Superconductor, Rubber/Plastics, Photography, Holography, Chemicals, Glasses

OthersG


9


A B C D E F G

Users

Fig. 1 Relative Share of Cleanrooms Users (See Table 1)

10

Outline

Introduction


Contamination

Testing


HVAC System Design

Air Flow Pattern

Air Filtration

Design Parameters

Air Distribution

T & RH Control


Validation Tests

HVAC System Cost


Anterooms

11

Cleanroom Standards and

Classifications

The most widely accepted standards of cleanroom are:

ISO EN 14611-1 1999

US Federal Std 209E 1992

German VDI 2083 1990

EEC cGMP 1989

France AFNOR 1989

British BS 5295 1989

Japan JIS B 9920 1989

3

12


Classifications

Table 2 Air Classifications for Internal Cleanroom Standards

(New WayZ, 2003)

Approx.ParticlesPer m3

0.5mµµµµ

ISOEN 14644-1

1999

US209E1992

US209E

Imperial

GermanyVDI20831989

EECCGMP1989

FranceAFNOR

1989

BritainBS 5295

1989

JapanJIS B99201989

1

3.5 2 0 2

10 M 1

35 3 M 1.5 1 1 C 3

100 M 2

353 4 M 2.5 10 2 D 4

1000 M 3

≥

13

Approx.ParticlesPer m3

0.5mµµµµ

ISOEN 14644-1

1999

US209E1992

US209E

Imperial

GermanyVDI20831989

EECCGMP1989

FranceAFNOR

1989

BritainBS 5295

1989

JapanJIS B99201989

3530 5 M 3.5 100 3 A+B 4000 E or F 5

10000 M 4

35300 6 M 4.5 1000 4 G or H 6

100000 M 5

353000 7 M 5.5 10000 5 C 400000 J 7

1000000 M 6

3530000 8 M 6.5 100000 6 D 4000000 K 8

10000000 M 7

100000000 9 M 7.5 1000000 40000000 L 9


Classifications

≥

14


Classifications

Table 3 Federal Standard 209D classification of cleanrooms

100,00010,0001000100101Federal Standard 209 classification

100,00010,0001000100101No. of particles/ft3, m 0.5 µ≥

15

The ISO standard has 9

classes for clean air: classes 1

to 9.

The ISO class: is related

particles of size 0.1 mµ or

larger.

Concentration limit Cn

The ISO standard

08.21.0 )(10 D

NnC =

4

16

The ISO standard

Table 4 Airborne Particulate Cleanliness Classes

(by cubic meter) as per ISO 14644-1

CLASSNumber of Particles per Cubic Meter by Micrometer Size

0.1 µµµµm 0.2 µµµµm 0.3 µµµµm 0.5 µµµµm 1 µµµµm 5 µµµµm

ISO 1 10 2

ISO 2 100 24 10 4

ISO 3 1,000 237 102 35 8

17

The ISO standard

Number of Particles per Cubic Meter by Micrometer SizeCLASS

5 µµµµm1 µµµµm0.5 µµµµm0.3 µµµµm0.2 µµµµm0.1 µµµµm

833521,0202,37010,000ISO 4

298323,52010,20023,700100,000ISO 5

2938,32035,200102,000237,0001,000,000ISO 6

2,93083,200352,000ISO 7

29,300832,0003,520,000ISO 8

293,0008,320,00035,200,000ISO 9

18

Table 5 Applications of ISO Class 1 to 8

ApplicationUS

209EISO

Class

Latest wafer and chip manufacturing, Hard disk manufacturingISO 1

Semi-conductor manufacturing, Pharmaceutical productsISO 2

Compact disk manufacturing, Optical manufacturing, Integrated circuits manufacturing

1ISO 3

High speed video duplication, Glass lamination, semi-conductors manufacturing

10ISO 4

Applications of bacteria-free or particulate free environment like manufacturing of aseptically-produced injectable medicines. Immuno-suppressed patients (e.g. after bone marrow transplant operations)

100ISO 5

19

ApplicationUS

209EISO

Class

Manufacture of high quality optical equipment. Assembly and testing of precision gyroscopes. Assembly of miniaturised bearings.

1000ISO 6

Assembly of precision hydraulic or pneumatic equipment, servo-control valves, precision timing devices, high grade gearing.

10,000ISO 7

General optical work, assembly of electronic components, hydraulic and pneumatic assembly.

100,000ISO 8

Table 5 Applications of ISO Class 1 to 8

5

20

Outline

Introduction


Contamination

Testing


HVAC System Design

Air Flow Pattern

Air Filtration

Design Parameters

Air Distribution

T & RH Control


Validation Tests

HVAC System Cost


Anterooms

21

Airborne Contaminants in

CleanroomsInternal sources: people (finger

prints, skin oil, hand cream, face

cream, polish, face powder, body

oil and grease, skin, scales, hair,

clothing lint, sneezing, coughing,

etc.).

Internal sources: process equipment

and manufacturing process

(emission of gases, oil, grease, oil

vapors, and particle shedding

materials).

External sources: infiltration to

cleanroom.

22

Airborne Contaminants in

Cleanroom

Table 6 Particle Size Distributions from Human Sneeze or

Cough

CoughSneezeDiameter in micrometer

66,000800,000< 1

21,000686,0001 - 2

1,600280,0002 - 4

1,290134,0004 - 8

49036,0008 - 16

854,50022

90,7651,940,000Total23

Outline

Introduction


Contamination

Testing


HVAC System Design

Air Flow Pattern

Air Filtration

Design Parameters

Air Distribution

T & RH Control


Validation Tests

HVAC System Cost


Anterooms

6

24

Testing of Air Classification

Sampling the environment using a

proprietary automatic air sampler is

the most common method.

Standards for cleanroom monitoring

require assessment of number of

particles over a range of at least 2

sizes.

Normally it is common to use

0.5µm and 5µm as the range

reported.

25

There are possible three states to exist in a clean

space:


1. Clean space commissioned but without equipment

installed.

2. Clean space completely fitted out and operational,

without personnel movement.

3. Clean space fully operational under normal or worst case

conditions.

26


Table 7 Required Testing as per ISO 14644-2

Schedule of Tests to Demonstrate Continuing Compliance

Test Parameter ClassMaximum

Time IntervalTest Procedure

Particle Count Test<= ISO 5 6 Months

ISO 14644-1 Annex A > ISO 5 12 Months

Air Pressure Difference All Classes 12 Months ISO 14644-1 Annex B5

Airflow All Classes 12 Months ISO 14644-1 Annex B4

27


Table 8 Optional Testing as per ISO 14644-2

Schedule of Additional Optional Tests

Test ParameterClassMaximum

Time Interval

Test Procedure

Installed Filter LeakageAll Classes24 MonthsISO 14644-3 Annex B6

Containment LeakageAll Classes24 MonthsISO 14644-3 Annex B4

Airflow VisualizationAll Classes24 MonthsISO 14644-3 Annex B7

7

28

Outline

Introduction


Contamination

Testing


HVAC System Design

Air Flow Pattern

Air Filtration

Design Parameters

Air Distribution

T & RH Control


Validation Tests

HVAC System Cost


Anterooms

29


Conventional Clean Area.

Unidirectional flow Clean Area.

Mixed flow Clean Area.

Isolators or Microenvironment Clean Area.

30

Conventional Clean Area

Turbulently-ventilated or

non-unidirectional flow.

Area is distinguished by

their method of air supply.

Air supply diffusers or

filters in the ceiling.

Return air from grills in

ceiling, low-side wall, or the

floor.

31

Unidirectional flow Clean Area

Widely known as clean area

with laminar flow, which is

terminologically wrong.

Supply: bank of high

efficiency filters (HEPA).

Return/ exhaust air is from

low-side wall or floor.

8

32

Mixed flow Clean Area

Cleanroom is

conventionally

ventilated but where the

product is exposed to

contamination, a

unidirectional flow

cabinet or workstation

is used.

33

Isolators or Microenvironment

Clean Area

Fig 5 Isolator used to protect the critical production area

These are used within a cleanroom.

34

Contaminated Rooms

Manufacturing processes:

toxic chemicals or

dangerous bacteria.

Examples: pharmaceutical

industry and biotechnology

industry.

Design of contaminated

rooms: similar to that used

in cleanrooms.

35

Outline

Introduction


Contamination

Testing


HVAC System Design

Air Flow Pattern

Air Filtration

Design Parameters

Air Distribution

T & RH Control


Validation Tests

HVAC System Cost


Anterooms

9

36

HVAC System Design

Cleanrooms HVAC system design: clean class.

Control the internal environment of cleanroom.

Function:

Cleanliness level

Room temperature and

relative humidity

37

Room clean class: controlling both external and

internal source of contaminants.

Controlling external source:

HVAC System Design

Filtration of all outdoor air to the room.

Keeping room at higher pressure than surroundings.

Sealing of opening in room where penetration of

ducts or pipe may exist.

Controlling the internal sources:

Proper gowning procedure.

Proper cleanroom garments.

Proper airflow pattern and quantity.

38

Requirement of HVAC System

Airflow rate to the room (ACH)

Airflow distribution in the room

Airflow pattern.

Location of air supply

outlet and air return grills.

Clean air velocity entering

the room.

Return air face velocity at

return air grill.

39

Type of air filter and its

efficiency.

Control system to maintain

room pressure and temperature

and/ or relative humidity.

Supply air temperature and/ or

humidity to the room (if

applied).

Requirement of HVAC System

10

40

Table 9 Recommendation of HVAC Design Parameters for

Various Cleanroom Classes

ISO ISO 3 ISO 4 ISO 5 ISO 6 ISO 7 ISO 8 Ref

FS 209 1 10 100 1,000 10,000 100,000

ACH (Note 1) 540-600+ 540-600 400-480 120-150 45-60 20-30 1

360-540 300-540 240-480 150-240 60-90 5-48 2, 6

500-600 500-600 500 40-120 20-40 10-20 3

600 250-600 150-250 50-120 20-50 4

250-700 5

450-640 420-600 300-480 180-300 36-90 6

41


FS 209 1 10 100 1,000 10,000 100,000

Ceiling

coverage98% 85-90% 60-80 40-50% 10-20% 5% 1

100% 100% 100% 25-40% 20% 10% 2

90-100% 90-100% 90% 20-50% 10-20% 5-10% 3

100% 70-100% 30-60% 10-30% 5-10% 4

100% 100% 75% 40% 30% 15% 6



42


Filter Type ULPAHEPA

ULPA

HEPA

ULPAHEPA HEPA HEPA

1, 2,

6

Filter

efficiency, %

99.9995

@ .12 micron

99.999

@ 0.3 micron

99.99 99.99 99.97 95.00 1

99.9995

@ .12 micron

99.99

@ 0.3 micron

99.99

@ 0.3 micron

99.99

@ 0.3 micron

99.99

@ 0.3 micron

2

99.99995

@ .12

99.99995

@ .12

99.99995

@ .12

99.99995

@ .12

99.99

@ .3 to .5 micron

99.99

@ .3 to .5 micron

6



43


Raise floor

returnmust must best best

1,2

Low wall

returnNote 2 common common common 1,2

common common common common common 4

Ceiling return common common 1,2

common 4

Max

horizontal

distance to return, m

3 6 9

Unidirectional

flowMust Must Must 2, 6

11

44


Inlet clean air

velocity, m/s. See Note 3

0.305-.457 0.005-0.041 0.203-.406 0.127-.203 0.051-076 0.005-.041 2

0.45 0.45 0.45 0.15 -0.45 0.15 - 0.45 0.15- .0.45 3

0.36- 0.56 0.36- 0.56 0.36- 0.56 0.36- 0.56 0.36- 0.56 0.36- 0.56 4

0.38-0.46 0.36-0.41 0.26-0.36 0.15-0.25 0.10-0.15 0.08-0.1 6

Return air

face velocity,

m/s.

0.5 - 1 1 – 2.5 2.5 3



45

Note 1: Upper limit of ACH my be increased as required by heat load

Note 2: Possible only when wall distance from room center does not exceed 12 ft (3.6 m)

Note 3: Clean air velocity is taken as the terminal outlet air velocity to space

Ref 1: www.modularcleanrooms.com

Ref 2: Engineering Manual (2000)

Ref 3: Communication and visit to several cleanrooms existing facilities

Ref 4: National Partitions and Interior, Inc (1998)

Ref 5: Rumsey (2003)

Ref 6: Jaisinghani (2003)

Ref 7: Pavlotsky (2004)



46

Outline

Introduction


Contamination

Testing


HVAC System Design

Air Flow Pattern

Air Filtration

Design Parameters

Air Distribution

T & RH Control


Validation Tests

HVAC System Cost


Anterooms

47

Air Flow Pattern

Factors for selection of

airflow pattern:

Clean class of the room

Equipment layout

Available space for

environmental control

equipment (AHU,

HEPA filter, etc.)

Available investment.

Types: unidirectional and the

non-unidirectional air flow

patterns.

Unidirectional airflow

pattern: parallel streamlines.

Non-unidirectional flow:

airflow is not in parallel

streamlines.

12

48

Fig. 7 Schematic of unidirectional airflow pattern in a cleanroom with

return air at low-wall level


49

Unidirectional airflow: ISO 5 or better.

Unidirectional airflow: Vertical or horizontal air flow.

Vertical flow:

Clean air from the ceiling and air return through the

floor or low-level sidewall.

Advantage that it washes internal generated particles

in the outlet direction from the room.


50

Horizontal flow:

Clean air from one wall and returned through the opposite

wall.

Disadvantage: contaminating particles to another location

where cleanliness level is very critical to maintain.

For this reason horizontal unidirectional air flow pattern is

limited in its application.


51

Fig. 8 Schematic of non-unidirectional airflow pattern in a cleanroom with

return air at low-wall level

Non-unidirectional airflow

13

52

Non-unidirectional airflow

Non-unidirectional airflow: clean air from some parts in

ceiling and returning the air from floor, low-level

sidewall, or from some parts in the ceiling.

Flow: non-parallel streams.

Rooms are cleaned by dilution effect.

This type of flow is not recommended for clean class

level of ISO 5 or better.

53

Unidirectional Workstations

Unidirectional airflow pattern: clean classes of ISO 5 or

better (High ACH).

Energy saving: unidirectional workstations are usually

recommended for the manufacturing process.

54Fig. 9 Unidirectional Vertical Flow Workstation


55


Fig. 10 Unidirectional Horizontal Flow Workstation

14

56

Outline

Introduction


Contamination

Testing


HVAC System Design

Air Flow Pattern

Air Filtration

Design Parameters

Air Distribution

T & RH Control


Validation Tests

HVAC System Cost


Anterooms

57

Function: control of particulates and airborne

microorganisms from external and internal

sources.

Design Factors:

Resistance to airflow

through the filter

Clean class

Air Filtration

58

• Types of Filters: HEPA &

ULPA

• Filter efficiency:Arrestance

Dust-Spot Efficiency

Particle Size

Efficiency.

Fractional Efficiency

or Penetration: DOP

efficiency

Air Filtration

59

Expression for a fractional efficiency:

inoutinf CCC /)( −=η

Standard efficiencies:

HEPA filters: 99.95%, 99.97% and 99.99 @ 0.3 mm

size particle.

ULPA air filters: 99.9995% @ 0.12 mm size particle

Supper ultra ULPA air filter: 99.999999% @ 0.12

mm size particle.

Air Filtration

15

60

Recommended air face velocity: 90 fpm.

HEPA filters fan-powered terminal modules

Air Filtration

61

Importance of Air change rates per hour (ACH).

Impact of ACH on fan sizing (construction cost)

and energy use.

Table 9: conflicting sets of recommendations.

ACH for some existing facilities: see Figure 11.

Air Change per Hour

62

Air Change per Hour

Many of the

recommended ACH are

based on relatively low-

efficiency filters that were

prevalent several years

ago.

Example ISO class 5:

from 250 to more than

700 air changes per hour

63

0

50

100

150

200

250

300

A B C D E F G H

Facilities

Air C

hange p

er Hour

Air Change per Hour

Fig. 11 Actual air change per hour for some existing

facilities of ISO Class 5 (see Rumsey2003)

16

64

Air Change per Hour

65

Outline

Introduction


Contamination

Testing


HVAC System Design

Air Flow Pattern

Air Filtration

Design Parameters

Air Distribution

T & RH Control


Validation Tests

HVAC System Cost


Anterooms

66

Design parameters that are related to one another:

Room airflow velocity

The ceiling coverage

fraction

The number of air

changes per hour.

Relation between Air Flow Design

Parameter

67


Parameter

17

68

Airflow velocity: 0.45 m/s or higher was used to assure

cleanliness level for ISO class 3, 4 or 5 in unidirectional

flow.

The air outlet velocity will be the same as the HEPA

filter face velocity

WLCuQ f 3600=


Parameter

69

This gives a room airflow average velocity ur that is

expressed by the following equation


Parameter

CuWLQu fr == )3600/(

ACH :

HCuWLHQACHf

/ 3600)/( ==

70

Table 10 Calculated ACH, Q, and Ur for various ISO classes

ISO Class

L W H Uf C Q Ur ACHC ACHR

m m m m/s m3/hr m/s

8 3 2 3 0.5 0.05 540 0.03 30 20-30

7 3 2 3 0.5 0.10 1080 0.05 60 45-60

7 3 2 3 0.5 0.20 2160 0.10 120 54-60

6 3 2 3 0.5 0.40 4320 0.20 240 120-150

6 3 2 3 0.5 0.50 5400 0.25 300 120-150

5 3 2 3 0.5 0.60 6480 0.30 360 400-480

5 3 2 3 0.5 0.80 8640 0.40 480 400-480

4 3 2 3 0.5 0.85 9180 0.43 510 540-600

4 3 2 3 0.5 0.90 9720 0.45 540 540-600

3 3 2 3 0.5 0.98 10584 0.49 588 540-600 71

Well Mixed Room Model

sti

steC

s

ketC

−−+−= )1()(

KV

Q

V

Qs f

of ++−= ηη )1(

GV

QCk o

of +−= )1( η

Modeling Prediction of Air Flow

Rate

18

72

Clean Air Dilution Model:

Q

GCC i +=

))(1()1( CCQ

QCC of

ofi −−+−= ηη


Rate

73Fig 12 Well-mixed cleanroom model Schematic


Rate

74


Rate

Fig. 13 Model schematic of clean air dilution of cleanroom 75


Rate

CFD Model

19

76

Outline

Introduction


Contamination

Testing


HVAC System Design

Air Flow Pattern

Air Filtration

Design Parameters

Air Distribution

T & RH Control


Validation Tests

HVAC System Cost


Anterooms

77

HVAC Air Distribution System

Air Flow Rate

Requirements of airflow rate to a cleanroom:

1. Cooling/heating load

2. Moisture load

3. Contamination load

Cleanliness level is the controlling factor for low

clean class (i.e. cleaner rooms).

78

Alternative A: commonly used for ISO class 6 to 9.

Fig. 14 Alternative A: Supply air using AHU with HEPA air filter

Alternatives of Air Distribution

System

79

Alternative B:

Fig. 15 Alternative B: Supply air using AHU and air outlet HEPA filter

modules


System

20

80

Alternative C: appropriate for ISO class 9 to 6

Fig. 16 Alternative C: Supply air using primary AHU with cooling and /or

heating coil and Secondary AHU with HEPA air filter


System

81

Alternative D: ISO clean class 5 or lower.


System

Fig. 17 Alternative D: Supply air using AHU and Fan-powered HEPA filter

modules

82

Outline

Introduction


Contamination

Testing


HVAC System Design

Air Flow Pattern

Air Filtration

Design Parameters

Air Distribution

T & RH Control


Validation Tests

HVAC System Cost


Anterooms

83

Temperature and Relative

Humidity Control

Why to control T & RH

Controlling supply air temperature: Chilled water or

DX cooling coils

High limit of RH is usually the concern of RH control

in cleanrooms

Approaches to humidity control: air conditioning and

desiccants

21

84

Outline

Introduction


Contamination

Testing


HVAC System Design

Air Flow Pattern

Air Filtration

Design Parameters

Air Distribution

T & RH Control


Validation Tests

HVAC System Cost


Anterooms

85

Cleanrooms: to avoid cross contamination with adjacent

spaces (when applied)

This can be achieved by keeping cleanroom:

at negative pressure, when the source of

contamination is inside the room, or

at positive pressure when the source of

contamination is outside


86

Pressurization Level:

Safety considerations: doors can be operated properly

and safely

Possibility for the pressurized space to implode,

blasting ceiling panels downward

To maintain accurate temperature and/or humidity

control it is desirable to minimize the quantity of air

being infiltrated to or ex-filtrated from the space.


87

Recommendation: 10 Pa between adjacent rooms of

different pressure levels

Methods to keep cleanrooms at a specified level of

pressurization.


Airflow supply and return/exhaust offset

Airflow tracking

Differential pressure control

22

88

Airflow supply and return/exhaust

offset

Fig. 18 Pressurization using airflow supply and exhaust / return offset89

Disadvantage: changing the pressurization level of

cleanroom by door opening/ closing.

Fig 19 Pressurization using airflow tracking

Airflow tracking

90

Using transfer grills

Airflow tracking

Fig 20 Controlling cleanroom pressure using adjustable gravity type

transfer grill (to be used only with airflow offset or airflow tracking

methods)91

Differential pressure control

Fig 21 Pressurization using differential pressure control by

modulating either airflow supply or airflow return / exhaust

23

92

Outline

Introduction


Contamination

Testing


HVAC System Design

Air Flow Pattern

Air Filtration

Design Parameters

Air Distribution

T & RH Control


Validation Tests

HVAC System Cost


Anterooms

93

HVAC Systems Validation Tests

Airflow velocity and uniformity

HEPA filter installation leak

Room airborne particle count t

Enclosure pressurization

Sound level measurements

Temperature and humidity uniformity

Recovery

Induction leak

Particle fallout count

94

Outline

Introduction


Contamination

Testing


HVAC System Design

Air Flow Pattern

Air Filtration

Design Parameters

Air Distribution

T & RH Control


Validation Tests

HVAC System Cost


Anterooms

95

Ready to use recipes for design:

Very common to avoid

potential design risks of

new approaches

Recipes usually lead to

higher construction cost

HVAC System Cost

24

96

Major elements contributing to high design cost:

HVAC System Cost

Rate of Air Change per

Hour

Flow Pattern

Air Filtration Process

Sizing and

Specifications of Air

Handling Units

97

Table 10 Summary of Expected HVAC Construction Costs

Item ISO 3 ISO 5 ISO 7 ISO 8Air change rate 0.19 Reference -0.072 -0.08

Airflow pattern 0.18 Reference -0.067 -0.073

Air filtration 0.10 Reference -0.028 -0.032

Air handling units 0.15 Reference -0.063 -0.07

Air pressure differential control 0.08 Reference -0.033 -0.041

Temperature control 0.15 Reference -0.026 -0.032

Humidity control 0.19 Reference -0.032 -0.034

Exhaust system 0.16 Reference -0.028 -0.031

Energy conservation 0.15 Reference -0.015 -0.017

Others 0.88 Reference -0.176 -0.2

TOTAL 2.23 Reference -0.54 -0.61

Construction cost

(Key Value Factor)2.23 1 0.46 0.39

98

Relative Cost of HVAC System

0

0.5

1

1.5

2

2.5

ISO 3 ISO 5 ISO 7 ISO 8

ISO Class

Rela

tive C

ost to ISO 5

Fig. 22 Relative HVAC cost of various ISO Classes to that of ISO 5

HVAC System Cost

99

Outline

Introduction


Contamination

Testing


HVAC System Design

Air Flow Pattern

Air Filtration

Design Parameters

Air Distribution

T & RH Control


Validation Tests

HVAC System Cost


Anterooms

25

100

Select a sealed light fixture that prevents the

contamination of the cleanroom during

lighting, re-lamping and fixture

maintenance

Special design and shape of fixtures should

be used to avoid potential storage areas for

contaminants such as seams gaps between

parts.

Special types of light fixtures:

Additional Design Consideration

Lighting Cleanrooms

A light fixture that mounts on the

“T” grid

A flow through fixture that mounts

under the HEPA filter and allows

the clean air to pass through it.

101

Fig. 23 T drop light fixtures


Lighting Cleanrooms

102


Lighting Cleanrooms

Fig. 24 Flow-Thru light fixtures103

Outline

Introduction


Contamination

Testing


HVAC System Design

Air Flow Pattern

Air Filtration

Design Parameters

Air Distribution

T & RH Control


Validation Tests

HVAC System Cost


Anterooms

26

104

Anterooms

Location: adjacent to the

cleanroom

Function: to create an area in

close proximity to the

cleanroom where technicians

perform support tasks

Advantages: reduces the risk of

contamination in the cleanroom

Anteroom cleanroom rating:

usually Class 100,000,

depending on the risk level of

sterile products being prepared

in the critical 105

Date post:	21-Apr-2017
Category:	Engineering
Upload:	moustafa-m-elsayed
View:	63 times
Download:	9 times