This document summarizes a study comparing traditional microglass HEPA filters to newer PTFE HEPA filters in cleanroom HVAC systems. Testing in a test rig found the PTFE filters had 30-36% lower pressure drops than microglass filters, indicating potential energy savings. Simulation estimated the PTFE filters could reduce one facility's annual energy consumption by 9,350 kWh. Additional benefits of PTFE filters included longer lifetimes and recertification periods, reducing costs. Future studies were planned to further evaluate PTFE filter performance and energy savings.

1. Low Energy Cost and High
Reliability Solution for
Cleanroom HVAC Systems
John Clapham, Dr. Rahul Bharadwaj, and Gordon Livingston

2. 2
•Agenda
1. Introduction to PSC and BioTechnique
2. Facility History
3. Study Hypothesis
4. HEPA Filter Medias
5. How HEPA Filters Fail
6. AHU Energy Saving Strategy
7. How Cleanroom Air Flow is Set Up
8. Our HEPA Filter Test Rig
9. Results of Our Testing
10. Energy and Cost Savings
11. Conclusions
12. Future Studies

3. 3
•BioTechnique is a brand new facility purposefully built for high potency
and cytotoxic drug fill and finish capabilities.
•Facility History
•2008: Construction completed for Mentor Biologics.
•2014: PSC acquired the facility and plans to operate as a CMO.
•2015: BioTechnique customer ready.

4. 4
•Facility

5. 5
•The Model
BioTechnique’s Big Idea: Use lower pressure-drop PTFE HEPA filters in our
ISO 5 and ISO 7 cleanrooms to reduce energy costs and to increase reliability.
• What is a PFTE HEPA filter?
• Why does it have a lower pressure drop?
• How can we objectively test PTFEs against traditional microglass filters?
• What is the actual pressure drop of a PTFE HEPA filter vs. a microglass HEPA filter?
•Our Proposition

6. HEPA Filter Media
• Traditional Microglass
6
• PTFE (polytetrafluoroethylene)
• GLASS MEDIA
• Tensile Strength (Typical)
•
• MD 1.3 kN/m2
• CD 0.7 kN/m2
• Elongation (Typical)
•
• MD 1.3 %
• CD 1.7 %
• PTFE MEDIA
• Tensile Strength (Typical)
•
• MD 5.5 kN/m2
• CD 2.5 kN/m2
• Elongation (Typical)
•
• MD 45 %
• CD 55 %
PTFE Media is more reliable and more energy efficient
than traditional Microglass Medias used in HEPA Filters.

7. How HEPA Filters Fail
HEPA Filters typically fail due to some form of contact combined with
the poor mechanical strength of the media
Testing &
Validation
• Removing/installing
• Scanning of filters
Cleaning
• Cleaning the screen
• High pressure water
Unintended
Contact
• Moving equipment
• Repair/maintenance
Handling
• Transport/delivery
• Installing
HEPA Filter Failure Modes
7

8. PTFE membrane
at 5,000x magnification
Traditional media
at 5,000x magnification
PTFE Technology Lowers Risk
Traditional media’s failure rate of 3% to 5% during 6-month
validation intervals will be near 0% with ePTFE technology
Traditional media fibers
FRACTURE
when folded

9. What gives PTFE its unique
properties?
• Fluorocarbon solid – strong bonding
• High molecular weight (at least
5,000,000) – long chain
• High Melting point (327oC) – long
chain
• Hydrophobic – bonding structure
• Third lowest coefficient of friction
(0.05 to 0.10) against any solid –
Slipperiness
• Inert to any chemical
What is PTFE?
Chemically
• Polytetrafluoroethylene
- ethylene
2 carbon (black)
atoms
-tetra –fluoro -
4 fluorine (green) atoms
Poly - repeating
molecular structure
Note that the fluorine
atoms completely
surround the central
polyethlyene chain

10. • PTFE Facts
• Average membrane pore size
0.5 – 1 micron, effective pore
size much smaller.
• Traditional non-woven membranes
typically have a 20 micron pore size.
• 100 million pores per square centimeter.
• Can fit about
1000-2000 pores
across the tip of
a ball point pen. •2x
Energy
Savings
•1.63x
Longer
Service
Life
•PressureDrop
•Time
•Vendor Advertised Dust
Loading Capacities
•Energy Savings
Penalty for Running
Longer
•The ModelPTFE Filtration Facts
9

11. •Expanded
PTFE
Membrane
•(~ 100μm depth)
•Nonwoven Layer
(for support)
•Human Hair
•(~ 60um diameter)
•PTFE Nodes
(for structure)
•PTFE Fibrils
(for filtration)
•The reasons why PTFE has:
•High Efficiency
-many fibrils
• Low Pressure Drop
-thin fibrils
• Excellent Durability
-nonwoven layer gives
protection to membrane
•Ref: 100μm in SEM Scale
• ~1.5x Human Hair Diameter
•The ModelPTFE Composite Construction Close-Up
10

12. Air Handler Units (AHUs) account for up to 65% of all
energy costs in biopharmaceutical buildings.
Reducing the pressure drop across HEPA filters
directly reduces the operating cost of AHUs.
Industrial Facility Energy Usage Breakdown
Source: U.S. Department of Energy
11

13. 13
•The ModelTypical Cleanroom

14. Our HEPA Filter Test Rig Setup
• Air flows from the cleanroom
through a balometer, which
measures the air flow rate, and
then into the HEPA filter.
13

15. 15
•The Model
•Test Rig to Compare Microglass vs. ePTFE Filters (Front View)
•Test Rig

16. 16
•The Model
•Schematic of the test Rig •Schematic of the test rig

17. 17
•The Model
•Filter Loaded in the Test Rig
Test Rig

18. 18
•The Model
•Video of Test Rig Being Used
Test Rig Video

19. 19
•The Model
•Side View of Test Rig
•Test Rig – Side View

20. 18
Four different types of HEPA filters were tested.
• 100 mm Microglass A (legacy filters in facility)
• 100 mm Microglass B (for direct comparison)
• 50 mm PTFE (to demonstrate effectiveness
• 75 mm PTFE even with less filter area)
• Three filters of each type were tested. Each individual
filter was tested three times, for a total of thirty-six tests.
• Three trials on each filter ensures statistical significance.

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Results
Filter Model
Measured Air
Volumetric Flow Rate
(CFM)
Measured
Pressure Drop
(IWG)
Microglass A (100 mm) 507 0.313
Microglass B (100 mm) 504 0.261
PTFE (50mm) 506 0.221
PTFE (75mm) 507 0.201

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Results
30 % 36 %

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•The Model
•What are the predicted energy savings from using a lower pressure HEPA
filter for BioTechnique?
• Total Annual Projected Energy Savings for BioTechnique: 9,350 kWh
•Predicted Energy Savings Using Simulation Model
Filter Model Annual Base Energy
Consumption
Microglass A (100mm) 232 kWh
Microglass B (100mm) 195 kWh
PTFE (50mm) 165 kWh
PTFE (75mm) 150 kWh

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•The Model
•What are the other cost savings we hope to realize besides energy savings at
BioTechnique?
• Reduced Filter Change out Periods Resulting in Lower Labor Costs and
Disposal Costs
• Additional PAO Studies Will Be Performed to Determine Frequency
• Increased Recertification Period Resulting in Lower Labor Costs
• Reduced Filter Failure and EM Excursions Rate Resulting in Lower Production
Loss and Labor Costs
•Other Cost Savings Besides Energy

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•The Model
•What did we learn from our study at BioTechnique?
• PTFE is significantly stronger and more reliable than traditional microglass media.
• PTFE has a significantly lower pressure drop than traditional microglass media.
• PTFE has major energy savings for Grade A and Grade B cleanrooms.
•Conclusions

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•The Model
•Planned Studies for the Future (2015 & 2016):
• BioTechnique will perform a PAO loading study using the test rig to determine
the maximum loading capacity of PAO that can be sprayed on traditional
microglass media and PTFE media before breakthrough.
• BioTechnique will perform an “in-situ” test of both traditional microglass
HEPA media vs. PTFE media, measuring energy savings. The production
filling and capping rooms at BioTechnique will be used for the test. This will
include approximately 70 microglass HEPAs and 40 PTFE HEPAs.
•Next Steps

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Thank-you!
• John Clapham, BioTechnique, jclapham@biotechnique.com