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

2. 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

3. 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.

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

5. 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

6. 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

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

8. 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 , A2 Fine Test Dust, 23% powdered carbon and 5% milled cotton linters.

9. 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

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

11. 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

12. 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

13. 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

14. 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

15. Comparison of and EN779:2002

16. 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 µm
Liquid DEHS from 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

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

18. 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

19. 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

20. 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 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

21. 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): μm 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

22. 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 μm Particle Efficiency Leak Test

23. 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

24. 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

25. 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 PM 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.

26. 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

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

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