1. 1. Low Energy Cost and High Reliability Solution for Cleanroom HVAC Systems John Clapham, Dr. Rahul Bharadwaj, and Gordon Livingston
2. 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. 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. 4 Facility
5. 5. 5 The Model BioTechniques 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. 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. 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. 8. PTFE membrane at 5,000x magnification Traditional media at 5,000x magnification PTFE Technology Lowers Risk Traditional medias 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. 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. 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. 11. Expanded PTFE Membrane (~ 100m 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: 100m in SEM Scale ~1.5x Human Hair Diameter The ModelPTFE Composite Construction Close-Up 10
12. 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. 13 The ModelTypical Cleanroom
14. 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. 15 The Model Test Rig to Compare Microglass vs. ePTFE Filters (Front View) Test Rig
16. 16. 16 The Model Schematic of the test Rig Schematic of the test rig
17. 17. 17 The Model Filter Loaded in the Test Rig Test Rig
18. 18. 18 The Model Video of Test Rig Being Used Test Rig Video
19. 19. 19 The Model Side View of Test Rig Test Rig Side View
20. 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.
21. 21. 19 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
22. 22. 20 Results 30 % 36 %
23. 23. 23 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
24. 24. 24 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
25. 25. 25 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
26. 26. 26 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
27. 27. 27 Thank-you! John Clapham, BioTechnique, jclapham@biotechnique.com