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Case Study: Using Particle Assessment to Determine Ventilation (HVAC) Performance. Harry L. Skalsky PhD DABT Skalsky & Associates 27356 Becedas Mission Viejo, California (949) 855-2363. HISTORY. Industry - Aluminum Powders & Alumina Abrasives (NIOSH/OSHA)
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Case Study: Using Particle Assessment to Determine Ventilation (HVAC) Performance Harry L. Skalsky PhD DABT Skalsky & Associates 27356 Becedas Mission Viejo, California (949) 855-2363
HISTORY • Industry - Aluminum Powders & Alumina Abrasives (NIOSH/OSHA) • Indoor Air – Allergens and Irritant Dusts (Air-O-Cell etc.) • Hazardous Waste Site – Dust Excursions (Direct Reading Dust Monitors etc.) • Exposure Assessment - Particle Counter, Air-O-Cell, and NIOSH procedures.
HVAC System Evaluation(100% Ambient Air appeared to eliminate a airborne fungal spore problem) • Was HVAC System delivering excess fungal spores to the interior ? Or • Was the “cure”, a fortuitous occurrence ?
Collection Equipment • Particle Counter HHPC-6 Laser Particle Counter (six channels 0.3 to >10Fm) • Two Air-O-Cells at 15 lpm. (5 minutes - outside and 10 minutes - indoor hallway)
Supply Duct Monitoring • Balometer – to measure, record and monitor air flow throughout the 30 minute collection time. • Plastic Shroud – to prevent mixing with hallway air. • Collection delay - to allow “flushing” of bag prior to sampling.
Conclusions • HVAC Filtration Efficiency can be measured by a variety of different factors • Particle Counters and Air-O-Cells yield very different results in the field. • Paired Air-O-Cell samples yield a high degree of variability both in spore count (3-68%) and particle count (27-68%).