case study: using particle assessment to determine ventilation (hvac) performance

Case Study: Case Study: Using Particle Using Particle Assessment to Determine Assessment to Determine

Ventilation (HVAC) PerformanceVentilation (HVAC) Performance

Harry L. SkalskyHarry L. Skalsky PhD DABT PhD DABT

Skalsky & AssociatesSkalsky & Associates27356 Becedas27356 Becedas

Mission Viejo, CaliforniaMission Viejo, California(949) 855-2363(949) 855-2363

HISTORYHISTORY

Industry - Industry - Aluminum Powders & Alumina Aluminum Powders & Alumina Abrasives (NIOSH/OSHA)Abrasives (NIOSH/OSHA)

Indoor Air Indoor Air – Allergens and Irritant Dusts (Air-O-Cell – Allergens and Irritant Dusts (Air-O-Cell etc.)etc.)

Hazardous Waste Site Hazardous Waste Site – Dust Excursions – Dust Excursions (Direct Reading Dust Monitors etc.)(Direct Reading Dust Monitors etc.)

Exposure Assessment - Exposure Assessment - Particle Counter, Air-Particle Counter, Air-O-Cell, and NIOSH procedures.O-Cell, and NIOSH procedures.

Exposure Assessment Exposure Assessment (November (November 2001)2001)

Respirable DustTotal DustParticle CounterAir-O-Cellmg/m3mg/m3Particules/m3Structures/m3

<0.09<.0538667825499Location 2

<0.09<.053424739391Location 3

<0.09<.053378279670Location 6

HVAC System EvaluationHVAC System Evaluation((100% Ambient Air appeared to eliminate a 100% Ambient Air appeared to eliminate a

airborne fungal spore problem)airborne fungal spore problem)

Was HVAC System delivering excess Was HVAC System delivering excess fungal spores to the interior ?fungal spores to the interior ?

OrOr

Was the “cure”, a fortuitous occurrence Was the “cure”, a fortuitous occurrence ? ?

HVAC – Primary FilterHVAC – Primary Filter85% in 3 to 10 micron85% in 3 to 10 micron

HVAC – Final Filter HVAC – Final Filter 95% down to 0.3 micron95% down to 0.3 micron

Collection EquipmentCollection Equipment

Particle Counter HHPC-6 Particle Counter HHPC-6 Laser Particle Counter Laser Particle Counter (six (six channels 0.3 to >10channels 0.3 to >10m)m)

Two Air-O-Cells at 15 lpm. Two Air-O-Cells at 15 lpm. (5 minutes - outside and 10 (5 minutes - outside and 10 minutes - indoor hallway)minutes - indoor hallway)

Supply Duct MonitoringSupply Duct Monitoring

Balometer – Balometer – to measure, record to measure, record and monitor air flow throughout the and monitor air flow throughout the 30 minute30 minute collection time. collection time.

Plastic Shroud – Plastic Shroud – to prevent to prevent mixing with hallway air.mixing with hallway air.

Collection delay - Collection delay - to allow to allow “flushing” of bag prior to sampling. “flushing” of bag prior to sampling.

Particle/Structure CountsParticle/Structure Counts20% versus 100% Outside20% versus 100% Outside

Air-o-cellParticles/M3Particle Counts/ft3lessGreaterGreaterTotalthanthanthan

2 microns2 microns2 microns

61,69613,92814,8303,630,646Intake Air146,2616,61328,6711,193,123Intake Air

10,5192,749Hallway81,29827,928Hallway

2,536370220765,824Supply Air1,702272410268,466Supply Air

4%3%1%21%1%4%1%23%

Particle EfficiencyParticle Efficiency((System Average by Particle size)System Average by Particle size)

Supply/Intake Airborne Particulate

>10.0um5.0-10.0um2.0-5.0um1.0-2.0um0.7-1.0um0.3-0.7um

99.2%97.9%98.5%91.6%93.4%77.9%Recirculated(AM&PM)

100.0%99.2%98.8%94.3%94.8%71.4%Ambient (AM)

AOC Structure EfficiencyAOC Structure Efficiency((System Average by AOC Category)System Average by AOC Category)

98%96%99%78%90%99%99%98%

OTHERMINERALSBIOLOGICALAir-O-CellUnidentifiedMoldSkinStructures/

Fragmentsm3

97303787744338Intake Air2706237013841043Intake Air

146051765528Hallway25319545361345Hallway

216140774Supply Air26517716Supply Air

1E3

1E4

1E5

1E6

1E7

Str

uctu

res o

r C

ou

nts

/M3 o

f A

ir

1 2 3 4 5 6 7 8 9 101112131415161718192021222324252627282930313233343536

Number of data pairs

Particles >2um Structures >2um(A)Structures >2um(B)

Particle Counter vs Air-O-CellParticles/ Structures Greater Than 2um

Intake LocationIntake Location (day1&2)(day1&2)

1E1

1E2

1E3

1E4

1E5

1E6

1E7

1E8

1E9

Str

uctu

res o

r C

ou

nts

/M3 o

f A

ir

1 2 3 4 5 6 7 8 9101112131415161718192021222324252627282930313233343536

Number of Data Pairs

Particles <2um Structures <2um(A)Structures <2um(B)

Particle Counter vs. Air-O-CellParticles/Structures Less than 2 um

Intake LocationIntake Location (day1&2)(day1&2)

0

5000

10000

15000

20000

25000

30000

35000

Str

uctu

res/M

3 o

f A

ir

1 2 3 4 5 6 7 8 9 101112131415161718192021222324252627282930313233343536

Number of Data Pairs (Outside Intake)

Structures >2um(A)Structures >2um(B)

"Duplicate" Air-O-Cell - Particle DataAvg Count-12409 Avg Dif.- 3340 (27%)

Intake LocationIntake Location (day1&2) AOC > 2(day1&2) AOC > 2mm

0

10000

20000

30000

40000

50000

60000

70000

80000

Str

uctu

res/M

3 o

f A

ir

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

Number of Data Pairs (Hallway)

Structures >2um(A)Structures >2um(B)

"Duplicate" Air-O-Cell - Particle DataAvg Count=11142 Avg Dif.=3838 (34%)

HallwayHallway Locations Locations (day1) AOC > 2(day1) AOC > 2mm

SupplySupply Locations Locations (day1) AOC > 2(day1) AOC > 2mm

0

20

40

60

80

100

120

140

160

180

200

Str

uctu

res/M

3 o

f A

ir

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18


Structures/M3 (A)Structures/M3 (B)

"Duplicate" Air-O-Cell - Particle DataAvg. Count = 34 Avg. Diff = 23 (68%)

0

1000

2000

3000

4000

Sp

ores/M

3 o

f A

ir

1 2 3 4 5 6 7 8 9 101112131415161718192021222324252627282930313233343536

Number of Data Pairs (Outside Intake)

Spores/M3 (A)Spores/M3 (B)

"Duplicate" Air-O-Cell - Spore DataAvg. S/M3 = 948 Avg Diff =528 (55%)

Intake LocationIntake Location (day1&2) AOC – Spores(day1&2) AOC – Spores[5 Minute][5 Minute]

Hallway LocationsHallway Locations (day1&2) AOC – Spores(day1&2) AOC – Spores[10 minute][10 minute]

0

20

40

60

80

100

120

140

160

180

Sp

ores/M

3 o

f A

ir

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20


Spores/M3(A)Spores/M3(B)

"Duplicate" AOC Hallway Spore DataAvg=34 S/M3 Avg. Diff= 24 S/M3 (68%)

Supply LocationsSupply Locations (day1&2) AOC – Spores(day1&2) AOC – Spores[30 minute][30 minute]

0 1 2 3 4 5 6 7 8 9

10 11 12 13 14 15

Sp

ores/M

3 o

f A

ir

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17


Spores/M3(A)Spores/M3(B)

"Duplicate" AOC Balometer Spore DataAvg = 6.1S/M3 Avg Diff=0.2 S/M3 (3%)

ConclusionsConclusions

HVAC Filtration Efficiency HVAC Filtration Efficiency cancan be be measured by a variety of different factorsmeasured by a variety of different factors

Particle Counters and Air-O-Cells yield Particle Counters and Air-O-Cells yield veryvery different results in the field. different results in the field.

Paired Air-O-Cell samples yield a Paired Air-O-Cell samples yield a high high degree of variabilitydegree of variability both in spore count both in spore count (3-68%) and particle count (27-68%).(3-68%) and particle count (27-68%).

case study: using particle assessment to determine ventilation (hvac) performance

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