ASHRAE Journal - December 2020 - 21

TECHNICAL FEATURE

What's Next for Standard 52.2?

Current activity includes an ASHRAE research project
(RP-1784) evaluating how changes to the standard over
the past 15 years have improved its precision. Stay tuned.

References

1. ASHRAE Standard 52.2-2017. Method of Testing General Ventilation
Air-Cleaning Devices for Removal Efﬁciency by Particle Size.
2. ASHRAE Standard 52.2-1999, Method of Testing General Ventilation
Air-Cleaning Devices for Removal Efﬁciency by Particle Size.
3. ASHRAE. 2015. " Addendum a to ASHRAE Standard 52.2-2012,
Method of Testing General Ventilation Air-Cleaning Devices for Removal
Efﬁciency by Particle Size. "
4. Hanley, J.T., J. Elion. 2005. " Coordinate and Analyze Interlaboratory Testing of Filters Under ASHRAE Standard 52.2 to
Determine the Adequacy of the Apparatus Qualiﬁcation Tests. "
ASHRAE Research Report RP-1088, Final Report.
5. Hanley, J.T., P.A. Lawless. 2010. " Particle Counter
Speciﬁcations for use with Filter Performance Test Standard ANSI/
ASHRAE Standard 52.2. " ASHRAE Research Report RP-1287.
6. IEST. 2016. " IEST-RP-CC001, HEPA and ULPA Filters. "
Institute of Environmental Sciences and Technology.
https://tinyurl.com/y2qnsmc7
7. ISO. 2011. " Standard 29463-5:2011, High-Efﬁciency Filters and
Filter Media for Removing Particles in Air-Part 5: Test Method for

FIGURE 2 Particle size distributions.

ISO Urban
" Recirculated "

ISO Rural
Real: More Small

Flat
Real: More Large

30
Volume Distribution (%)

mass-based efﬁciencies can be calculated.
Actual buildings may have particle size distributions
that are richer in either small or large particles depending
on the sources present and other variables. Figure 2 shows
particle size distributions representative of different air
that is treated by indoor air ﬁlters, the distributions used
by the ISO 16890 test standard,20 and a simple ﬂat distribution. The real distributions were derived from data in
the work of Jiang and Boor.21 The recirculated curve was
derived by assuming a mid-level MERV ﬁlter was used,
thus removing larger particles from the air supply.
Since a particle size distribution is necessary for calculating a mass efﬁciency from particle size dependent
efﬁciencies, the ﬂat distribution, which approximates
the average of the distributions, was chosen as a logical
compromise among the varied choices. Thus, PM152.2,
PM2.552.2, and PM1052.2 correspond to PM1, PM2.5 and
PM10. These values should now be available on Standard
52.2-2017 test reports following ASHRAE's approval of
Addendum b22 (see post on the Standards Addenda page.
Since the PM52.2 are calculated using parameters that
have been in the standard since it was ﬁrst published,
PM52.2 values can be retroactively determined for ﬁlters
tested earlier. However, since the test has been modiﬁed
over time, the accuracy will be less if using data from
before 2017 when the standard's last major update was
completed.

25
20
15
10
5
0

0.10

1.00
Particle Size (µm)

10.00

Filter Elements. " International Organization for Standardization.
8. CEN. 2009. " EN 1822:2009 Test methods for EPA, HEPA, and
ULPA ﬁlters. " European Committee for Standardization.
9. Lehtimaki, M., A. Taipale, A. Saamanen. 2002. " Investigation
of Mechanisms and Operating Environments that Impact the
Filtration Efﬁciency of Charged Air Filtration Media. " ASHRAE
Research Project RP-1189, Phase 1 Report.
10. Hanley, J.T., M.K. Owen. 2003. " Develop a New Loading Dust and
Dust Loading Procedures for the ASHRAE Filter Test Standards 52.1 and
52.2. " ASHRAE Research Report RP-1190. Prepared by RTI for ASHRAE.
11. Owen, M.K., J.T. Hanley, D.S. Ensor, L.E. Sparks. 2003.
Residential and commercial air ﬁlter efﬁciencies. In Proceedings of
the Indoor Air Quality Problems and Engineering Solutions.
12. Raynor, P., S. Chae. 2003. " Dust loading on
electrostatically charged ﬁlters in a standard test and a
real HVAC system. " Filtration & Separation 40(2):35 - 39.
https://doi.org/10.1016/S0015-1882(03)80068-X
13. Owen, K., R. Pope, J. Hanley. 2013. " How do Pressure Drop,
Efﬁciency, Weight Gain and Loaded Dust Composition Change
Throughout Filter Lifetime? " ASHRAE Research Report RP-1360.
14. Li, T., J. Siegel. 2020. " Laboratory performance of new and
used residential HVAC ﬁlters: Comparison to ﬁeld results (RP1649). " Science and Technology for the Built Environment 26(6):844 - 855.
15. Fann, N., A.D. Lamson, S.C. Anenberg, K. Wesson, et al. 2012.
" Estimating the national public health burden associated with
exposure to ambient PM2.5 and ozone. " Risk Anal 32(1):81 - 95.
16. Pope, C.A., R.T. Burnett, M.J. Thun, E.E. Calle, et al. 2002.
" Lung cancer, cardiopulmonary mortality, and long-term exposure
to ﬁne particulate air pollution. " JAMA 287(9):1132 - 1141.
17. EPA. 2020. " Particulate Matter (PM) Pollution. " U.S.
Environmental Protection Agency. https://tinyurl.com/y256clcu
18. South Coast AQMD. 2020. " Air Quality. " South Coast Air Quality
Management District https://tinyurl.com/y4c5ev7f
19. CDC. 2020. " Particle Pollution. " Centers for Disease Control
and Prevention. https://tinyurl.com/y2h2s3kg
20. ISO. 2016. " Standard 16890:2016, Air Filters for General
Ventilation. " International Organization for Standardization.
21. Jiang, J., B. Boor. 2020. B.E. " Evaluation of ultraﬁne particle
source and loss processes with building energy
use data. " In preparation for submission to Energy
& Buildings.
22. ASHRAE. 2020. " Addendum b to ASHRAE
Standard 52.2-2017, Method of Testing General
Ventilation Air-Cleaning Devices for Removal Efﬁciency https://bit.ly/3dTa21p
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by Particle Size. "
D ECEM BER 2020

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ASHRAE Journal - December 2020

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