Download - NAFA Technical Seminar April 19, 2012
![Page 1: NAFA Technical Seminar April 19, 2012](https://reader036.vdocuments.us/reader036/viewer/2022062315/5681582b550346895dc59023/html5/thumbnails/1.jpg)
• NAFA Technical Seminar• April 19, 2012
ANSI/ASHRAE 52.2Can we fix this
Method of Test?
![Page 2: NAFA Technical Seminar April 19, 2012](https://reader036.vdocuments.us/reader036/viewer/2022062315/5681582b550346895dc59023/html5/thumbnails/2.jpg)
History of the Test procedure
• 10+ years in development prior to 1999 release • Task of 52.2 Committee "create a test method
based on particle size removal efficiency for end user evaluation of filter performance"
• Research projects led to greater understanding of the physical science in filtration
• MERV - scales were created with minimal data and educated guesses at value spread
![Page 3: NAFA Technical Seminar April 19, 2012](https://reader036.vdocuments.us/reader036/viewer/2022062315/5681582b550346895dc59023/html5/thumbnails/3.jpg)
![Page 4: NAFA Technical Seminar April 19, 2012](https://reader036.vdocuments.us/reader036/viewer/2022062315/5681582b550346895dc59023/html5/thumbnails/4.jpg)
Committee Efforts
• Std published in 1999 for the first usage• No revisions through 2007 (other than edits)• 2008 Arrestance and DHC were added from
52.1 predominantly for MERVs 1-4• 52.1 was removed from ASHRAE Standards• Addition of "Voluntary Conditioning Step"
![Page 5: NAFA Technical Seminar April 19, 2012](https://reader036.vdocuments.us/reader036/viewer/2022062315/5681582b550346895dc59023/html5/thumbnails/5.jpg)
MERV's Status?
• ASHRAE Rating system?
• No certification of personnel performing tests
• No policing entity to produce a rating system
![Page 6: NAFA Technical Seminar April 19, 2012](https://reader036.vdocuments.us/reader036/viewer/2022062315/5681582b550346895dc59023/html5/thumbnails/6.jpg)
![Page 7: NAFA Technical Seminar April 19, 2012](https://reader036.vdocuments.us/reader036/viewer/2022062315/5681582b550346895dc59023/html5/thumbnails/7.jpg)
ISO Standards
• Working groups creating standards for • Cleanroom and HEPA usage completed• UVC, Rotating Equipment, dust collection• Working group 3 - General HVAC filtration is
looking to use 52.2 MOT for developing PM efficiency values
![Page 8: NAFA Technical Seminar April 19, 2012](https://reader036.vdocuments.us/reader036/viewer/2022062315/5681582b550346895dc59023/html5/thumbnails/8.jpg)
Definition:•System of classification according to merit or amount
•Assessment of something in terms of quality, quantity or both
•What filter parameters should be included?Filter Performance – pressure drop, efficiency,
lifeEnergyPerceive ValueCost
Filter Rating
![Page 9: NAFA Technical Seminar April 19, 2012](https://reader036.vdocuments.us/reader036/viewer/2022062315/5681582b550346895dc59023/html5/thumbnails/9.jpg)
Is it possible to combine filter performance characteristics into one criterion?Greater value of the criterion equal to “better”
filter
Traditional quality factor (figure of merit):
o E – filter efficiency and ΔPo – filter pressure drop
Potential issues:
Different ΔPo units
Results at different flow rate
Filter Rating
oP
ELn
)1(
![Page 10: NAFA Technical Seminar April 19, 2012](https://reader036.vdocuments.us/reader036/viewer/2022062315/5681582b550346895dc59023/html5/thumbnails/10.jpg)
Example 1: E1 = 80% and ΔPo = 0.40” H2O
α1 = - ln (1 – 0.8)/ 0.40 = 1.609/0.40 = 4.02
Example 2: E1 = 80% and ΔPo = 0.30” H2O
α2 = - ln (1 – 0.8)/ 0.30 = 1.609/0.30 = 5.36
Example 3: E1 = 85% and ΔPo = 0.40” H2O
α2 = - ln (1 – 0.85)/ 0.40 = 1.897/0.40 = 4.74
Filter Rating
![Page 11: NAFA Technical Seminar April 19, 2012](https://reader036.vdocuments.us/reader036/viewer/2022062315/5681582b550346895dc59023/html5/thumbnails/11.jpg)
Single Aggregate Objective Function (AOF) Weighting method, linear AOF:
MAX
o E – filter efficiency; ΔPo – filter pressure drop
o C – filter cost; DHC – filter dust holding capacity
o λ – weighting factors; ∑ λi = λ1 + λ2 + λ3 + λ4 =1
o λ – weighting factors are assigned based on priority - subjective
Filter Rating
DHCCPEL 4321
![Page 12: NAFA Technical Seminar April 19, 2012](https://reader036.vdocuments.us/reader036/viewer/2022062315/5681582b550346895dc59023/html5/thumbnails/12.jpg)
Combination of objectives:
Other objectives: Cost,Energy
Filter Rating
DHCP
ELnDHCa
o
)1(
![Page 13: NAFA Technical Seminar April 19, 2012](https://reader036.vdocuments.us/reader036/viewer/2022062315/5681582b550346895dc59023/html5/thumbnails/13.jpg)
MERV – is MERV a rating system?
Residential filters – Home DepotFPR (Filter Performance Rating) = 1 – 10 scale
Weighted Average = λ1 (Efficiency Large Particles) +
λ2 (Efficiency Small Particles) + λ3 DHC
λ1 + λ2 + λ3 = 0.6 + 0.3 + 0.1 =1 FPR = 10 for Weighted Average > 25
Residential filters – 3MMPR – Microparticle Performance Rating
ability to capture particles 0.3 – 10 µm (E1)
Filter Rating - Examples
![Page 14: NAFA Technical Seminar April 19, 2012](https://reader036.vdocuments.us/reader036/viewer/2022062315/5681582b550346895dc59023/html5/thumbnails/14.jpg)
“Too Many MERV’s” ??According to ASHRAE and IEST – 20 Possible Assignable MERV’s
Three “Markets” E3 Arrestance MERV 1-4 General Equipment E2 Middle Efficiency MERV 5-12 Equipment and People E1 High Efficiency MERV 13-20 Marginalized Health People and Specialized End UsesReal Differences Between the Markets
Arrestance High Efficiency
Real Differences Within These Markets MERV 5 MERV12
DifficultiesVariety of End UsesVariety of Air Handling TypesVariety of Pollutants
![Page 15: NAFA Technical Seminar April 19, 2012](https://reader036.vdocuments.us/reader036/viewer/2022062315/5681582b550346895dc59023/html5/thumbnails/15.jpg)
Conditioning Step is Too Expensive
15
![Page 16: NAFA Technical Seminar April 19, 2012](https://reader036.vdocuments.us/reader036/viewer/2022062315/5681582b550346895dc59023/html5/thumbnails/16.jpg)
Conditioning Step Not Real World
16
Mechano-ElectretFilter
Mechanical OnlyFilter
![Page 17: NAFA Technical Seminar April 19, 2012](https://reader036.vdocuments.us/reader036/viewer/2022062315/5681582b550346895dc59023/html5/thumbnails/17.jpg)
52.2 Positive Attributesbefore Conditioning
17
![Page 18: NAFA Technical Seminar April 19, 2012](https://reader036.vdocuments.us/reader036/viewer/2022062315/5681582b550346895dc59023/html5/thumbnails/18.jpg)
Analogy—Gas Mileage Testing
http://www.caranddriver.com/reviews/2012-ford-focus-sel-test-review 18
![Page 19: NAFA Technical Seminar April 19, 2012](https://reader036.vdocuments.us/reader036/viewer/2022062315/5681582b550346895dc59023/html5/thumbnails/19.jpg)
ASHRAE 52.2-2007
Tom Justice
![Page 20: NAFA Technical Seminar April 19, 2012](https://reader036.vdocuments.us/reader036/viewer/2022062315/5681582b550346895dc59023/html5/thumbnails/20.jpg)
2010 Round Robin
![Page 21: NAFA Technical Seminar April 19, 2012](https://reader036.vdocuments.us/reader036/viewer/2022062315/5681582b550346895dc59023/html5/thumbnails/21.jpg)
2011 Round Robin
![Page 22: NAFA Technical Seminar April 19, 2012](https://reader036.vdocuments.us/reader036/viewer/2022062315/5681582b550346895dc59023/html5/thumbnails/22.jpg)
Issues under Review by Task Groups
• Current MERV boundaries• Humidity Range• OPC particle counter specifications• Air density calculation• Shedding• IPA vapor conditioning• Test variability
![Page 23: NAFA Technical Seminar April 19, 2012](https://reader036.vdocuments.us/reader036/viewer/2022062315/5681582b550346895dc59023/html5/thumbnails/23.jpg)
Reported Values
Channel E1 E2 E3 Reporting Value
Particle Size Range .3 to 1 1 to 3 3 to 10
Filter 1 37% 65% 84% MERV 8
Filter 2 36% 65% 85% MERV 11
![Page 24: NAFA Technical Seminar April 19, 2012](https://reader036.vdocuments.us/reader036/viewer/2022062315/5681582b550346895dc59023/html5/thumbnails/24.jpg)
![Page 25: NAFA Technical Seminar April 19, 2012](https://reader036.vdocuments.us/reader036/viewer/2022062315/5681582b550346895dc59023/html5/thumbnails/25.jpg)
![Page 26: NAFA Technical Seminar April 19, 2012](https://reader036.vdocuments.us/reader036/viewer/2022062315/5681582b550346895dc59023/html5/thumbnails/26.jpg)
![Page 27: NAFA Technical Seminar April 19, 2012](https://reader036.vdocuments.us/reader036/viewer/2022062315/5681582b550346895dc59023/html5/thumbnails/27.jpg)
![Page 28: NAFA Technical Seminar April 19, 2012](https://reader036.vdocuments.us/reader036/viewer/2022062315/5681582b550346895dc59023/html5/thumbnails/28.jpg)
![Page 29: NAFA Technical Seminar April 19, 2012](https://reader036.vdocuments.us/reader036/viewer/2022062315/5681582b550346895dc59023/html5/thumbnails/29.jpg)
![Page 30: NAFA Technical Seminar April 19, 2012](https://reader036.vdocuments.us/reader036/viewer/2022062315/5681582b550346895dc59023/html5/thumbnails/30.jpg)
![Page 31: NAFA Technical Seminar April 19, 2012](https://reader036.vdocuments.us/reader036/viewer/2022062315/5681582b550346895dc59023/html5/thumbnails/31.jpg)
Issues under Review by Task Groups
• Current MERV boundaries• Humidity Range• OPC particle counter specifications• Air density calculation• Shedding• IPA vapor conditioning• Test variability
![Page 32: NAFA Technical Seminar April 19, 2012](https://reader036.vdocuments.us/reader036/viewer/2022062315/5681582b550346895dc59023/html5/thumbnails/32.jpg)
Fig. 8 ASHRAE 1287 RPFig. 8 ASHRAE 1287 RP
![Page 33: NAFA Technical Seminar April 19, 2012](https://reader036.vdocuments.us/reader036/viewer/2022062315/5681582b550346895dc59023/html5/thumbnails/33.jpg)
KCL @ 0% to 85% RHKCL @ 0% to 85% RH
![Page 34: NAFA Technical Seminar April 19, 2012](https://reader036.vdocuments.us/reader036/viewer/2022062315/5681582b550346895dc59023/html5/thumbnails/34.jpg)
Other Potential Issues
• Test dust• Specifications for particle generator• Radioactive versus corona discharge in
neutralization of airstream• Initial resistance calibration