We provide superior filtration solutions to improve the quality of life Filtration Standards Presentation Dan Woodman April 23, 2010

Particle Filtration Standards Overview KEY POINTS EN 1822 is used for HEPA and ULPA Europe uses EN779, US uses ASHRAE 52.2 High Efficiency Particulate Air (HEPA) filters Ultra Low Penetration Air (ULPA) filters Fine dust filters Coarse dust filters Dust filters High efficiency air filters Air filters EN 779 G1 - G4 52.2 MERV 1-4 EN 779 F5 - F9 MERV 9-16 EN 1822 H10 - H14 EN 1822 U15 - U17 Group Sub-group Filter Class EN 1822 is most widely used test method for HEPA/ULPA filters even in the States. IEST-RP-CC007 is another method used by some labs in US to test HEPA/ULPA filters. IEST: Institute of Environmental Sciences and Technology Many Different Standards Exist

What is ASHRAE 52.2 Ranking and Reporting 16 MERV reporting values using Minimum Efficiency of 3 groups of average particle ranges (E1, E2, E3), average arrestance applied on MERV 1 – 4 Efficiency Challenge Aerosol Neutralized Solid Potassium Chloride (KCl) particles ranging in diameter from .3 to 10 μm Particle Counting Counting done alternately with dust loading intervals and 12 channels measured at each interval. Four channels averaged for each of 3 ranges (E1 from 0.3 to 1 μm, E2 from 1 to 3 μm, and E3 from 3 to 10 μm.) Arrestance Challenge Dust ASHRAE dust (Combined Arizona road dust, carbon black and cotton linters) Efficiency / DHC / Pressure Drop Relation Initial preload of 30 grams or ΔP of +10 Pa, then load in 25% increments of final ΔP. Arrestance reported on MERV 1 – 4 Final Pressure Drop At least twice the initial ΔP or as specified by MERV Range, whichever is greater.

ASHRAE 52.2 MERV Table Gravimetric Filters Arrestance Course Filters E3 Emphasis Medium Filters E2 Emphasis Fine Filters E1 Emphasis

ASHRAE 52.2 MERV Example Minimum Range Used for Reporting E2 Establishes the MERV E1 Establishes the MERV E1 Doesn’t Factor Minimum Range Used for Reporting

ASHRAE 52.2 MERV 8-11 Issue Correction Needed to Fix this Phenomenon KEY POINTS One % drop in E3 can result in 3 MERV Level Change First Run E1 = 33 % E2 = 72 % E3 = 86 % Second Run E1 = 35 % E2 = 71 % E3 = 84 % MERV 11 MERV 8 Source: Robert Burkhead, 2004 Correction Needed to Fix this Phenomenon

ASHRAE 52.2 MERV 8-11 Issue Modification is now on discussion *One Option Being Reviewed Modification is now on discussion

What is EN 779 Ranking and Reporting Nine filter classes based on average arrestance (G1 - G4) or 0.4 μm efficiency (F5 - F9) Efficiency Challenge Aerosol Neutralized liquid DiEthylHexylSebacate (DEHS) or equivalent particles ranging in diameter from 0.2 to 3 μm Particle Counting Counting done alternately with dust loading intervals using a minimum 5 bands measured at each interval. Arrestance Challenge Dust ASHRAE dust (a blend of A2 fine, carbon black and cotton linters) Efficience / DHC / Pressure Drop Relation Initial preload of 30 grams, then a minimum of four evenly distributed measuring points. Arrestance and DHC reported on all tests. Final Pressure Drop Max. 250 Pa for “coarse” grade filters (G1 – G4), 450 Pa for “fine” grade filters (F5 – F9) ASHRAE Dust is a custom blend of 72% ISO 12103-1, A2 Fine Test Dust, 23% powdered carbon and 5% milled cotton linters.

Calculate Average Efficiency and Arrestance Basic Test Scheme to EN 779 Measure Initial: P, Efficiency Load with ASHRAE Dust in steps until final P Measure P, Efficiency, Arrestance between loadings Measure Final: P, Efficiency, Arrestance Calculate Average Efficiency and Arrestance Report Initial, Average values with graphs attached

Efficiency as a Function of the Dust Feed Dust feed (ASHRAE dust) in g Average 63 %

Average Efficiency or Arrestance Used Over Dust Loading Curve EN779 Filter Class Table KEY POINTS Two groupings determined from Average Arrestance or Efficiency Average over loading is used for Filter Class Average Efficiency or Arrestance Used Over Dust Loading Curve

Annex A: Electrostatic discharging procedure Any treatment to give a completely discharged material may be used. In detail the treatment with isopropanol (IPA) is described. The initial efficiency of a treated and untreated media sample are measured and have to be stated on the test report. Sample of a synthetic micro fiber nonwoven dipped into isopropanol Synthetic micro fiber nonwoven after storage in isopropanol Information Reporting Only

Annex B: Shedding from filters (informative) The term „shedding“ comprises three separate aspects of filter behavior. Some or all of these phenomena are likely to occur to some extent during the life cycle of an installed filter. Particle bounce Release of fibers or particulate matter from filter material Re-entrainment of particles Information Reporting Only

Minimum Efficiency (IPA treated) Introduction Later this Year Draft of the new EN 779  Key Points New medium filter class introduced Discharge testing for F7-F9 based on IPA Current EN 779 New EN 779 Average Arrestance Average Efficiency Minimum Efficiency (IPA treated) G1 Am < 65% - G2 65% ≤ Am < 80 G3 80% ≤ Am < 90% G4 90% ≤ Am F5 M5 40% ≤ Em < 60% F6 M6 60% ≤ Em < 80% F7 80% ≤ Em < 90% 35% F8 90% ≤ Em < 95% 55% F9 95% ≤ Em 70% = New in the current draft of EN 779:2010 Introduction Later this Year

Comparison of 52.2-2007 and EN779:2002

Comparison of ASHRAE 52.2 and EN779 STANDARD ASHRAE 52.2 EN779 Ranking 16 MERV Values based on E1, E2, E3 MINIMUM INITIIAL efficiency 9 Filter Classes based on AVERAGE Arrestance (G1-G4) or 0.4 µm efficiency (F5-F9) Eff. Challenge Aerosol Solid KCl from 0.3 - 10 µm Liquid DEHS from 0.2 - 3 µm Partical Counting 12 Channels with Average in 3 Ranges min 5 bands Arrestance Challenge Dust ASHRAE Dust Eff. - DHC - dP 30 g or +10 pa ΔP preload whichever comes first, then 25% increments of ΔP. Arrestance reported for MERV 1-4 30 g preload then 4 evenly distributed points. Arrestance and DHC reported. Final dP min 2X initial ΔP or as specified by MERV Range, whichever is greater. Max 250 Pa for G1-G4, 450 Pa for F5-F9 Discharge Optional Appendix J uses KCl. None in Classification. IPA described and reported - Annex A. Shedding None in standard Informative Annex B. Very Different Standards

Comparison of ASHRAE 52.2 and EN779 Source: Robert Burkhead, 2004 No Direct Comparison Exists

Take Home Points The ASHRAE method 52.2 Popularly used in US Currently does not distinguish charged products Uses a solid aerosol challenge European method EN 779:2002 Used in Europe and global application is being sought Does provide charged fiber characterization Uses a liquid aerosol challenge Significant other differences

Performance Criteria of an HEPA/ULPA Filter Pressure drop at nominal volume flow rate Integral collection efficiency for the particle size with the highest penetration (MPPS = Most Penetrating Particle Size) at nominal volume flow rate Local collection efficiencies for the particle size with the highest penetration (MPPS) at nominal volume flow rate Freedom of leaks as of filterclass H13 according to EN1822

Test method to EN 1822 Determination of the MPPS at the plane medium at the nominal media velocity Measurement of the pressure drop Measurement of the fractional efficiency curve T(x) as a function of the particle size in the range 0,05µm to 0,5µm Determination of MPPS as minimum of the curve Leakage test of the complete filter element at nominal air flow rate (only HEPA und ULPA) Scan test: Measurement of the local efficiencies Alternatively for HEPA: Oil Thread Leakage Test or 0.3 - 0.5 μm Particle Efficiency Leak Test (only H13 & above) Measurement of the overall efficiency and the total pressure drop of the complete filter element at nominal flow rate Classification and supply of a test certificate part 3 part 4 part 5 part 1

New in EN 1822:2009 Introduction of group E (EPA) Filter classes H10-H12 have been renamed to E10-E12 Clear definition of group E (no individual test required, only factory test certificate, spot checks as part of a quality control system equivalent to ISO 9001) New Annexes in part 4 (Leakage test methods) Annex D (informative): Leak Test with solid PSL Aerosol Annex E (informative): 0.3 - 0.5μm Particle Efficiency Leak Test New Annexes in part 5 (measurement of efficiency) Annex A (informative): Testing and classification method for filters with MPPS ≤ 0.1μm (e.g. membrane medium filters) Annex B (normative): Testing and classification of filters using media with (charged) synthetic fibers

Filter classes and Efficiencies to EN 1822:2009 1) Vendor and buyer can agree upon lower local values than mentioned in the table 2) Determination of freedom from leaks can also be carried out by the Oil Thread Leakage Test 3) Determination of freedom from leaks can also be carried out by the 0.3 - 0.5 μm Particle Efficiency Leak Test

different interpretation of the test results Proposed ISO/TC142/WG9 Proposed test and classification system for static filters for gas turbine One common test method Loading dust is AC Fine, results are: Initial arrestance (gravimetric 50g loading), Initial efficiency DEHS (0.4µm) (untreated + treated) Efficiency DEHS (0.4µm) after 50g dust and final DHC Initial Arrestance SF-C1 – SF-C4 Minimum efficiency SF-F5 – SF-F7 SF-E8 – SF-E10 coarse fine HEPA different interpretation of the test results EN 779: G3 – F6 EN 779: F7 – F9 EN 1822: H10 – H12

Proposed ISO/TC142/WG9 Initial arrestance: The gravimetric efficiency is the weighted (mass) removal of loading dust after 50 g of dust load. Minimum of all measured 0.4μm efficiency values, being either: Initial filter efficiency Filter efficiency after 50 g dust loading Filter efficiency at 625 Pa final pressure drop Media efficiency after conditioning

Future Changes to Standards ISO TC142 WG3 Discussed the Following Concept for Filter Class: KEY POINTS Discharge Efficiency would be included as an adjustment Metric would be PM2.5 and PM10-2.5 efficiency Measure the clean filter efficiency in each particle size range. Measure the clean media efficiency on flat sheet of media used in the filter. Measure the discharged media efficiency on the flat sheet. Use ½ of the efficiency drop between initial flat sheet efficiency and discharged flat sheet efficiency in each particle size range to adjust filter efficiency.

Future Changes to Standards KEY POINTS Standardized PM10 Curve Needs to be Determined Mass distribution used by governments for IAQ standards Airborne particle distribution in dictated by physics Theoretical distribution based on physics Resultant mass distribution *Source US EPA Website

Future Changes to Standards Discharge adjusted efficiency for each particle range is cross multiplied by standardized PM2.5 curve and PM10-2.5 Curve KEY POINTS Final Filter Efficiency Would be Reported for PM2.5 and PM10-2.5 as a % X PM2.5 = 92% PM10-2.5 = 99%

We provide superior filtration solutions to improve the quality of life Filtration Standards Presentation Dan Woodman April 23, 2010