AAAR 31st Annual Conference
October 8-12, 2012
Hyatt Regency Minneapolis
Minneapolis, Minnesota, USA
Abstract View
HVAC Filters as Samplers of Particle-Bound Contaminants
JEFFREY SIEGEL, Kerry Kinney, The University of Texas at Austin
Abstract Number: 481 Working Group: Indoor Aerosols
Abstract Heating, ventilation, and air conditioning (HVAC) filters are left in place for long periods of time and are subjected to large airflows. Filters in recirculating conditioning systems thus provide a temporally and spatially integrated sample of indoor particles. When combined with an in-situ filter efficiency measurement and an assessment of the total volume of air that flows through the filter, a compositional analysis of the dust can reveal a time-integrated estimate of particle-size and contaminant resolved particle concentrations. We have used this technique to assess DNA-based microbial contaminant levels as well as heavy metal concentrations. The results from these assessments suggest considerable variation amongst similar buildings and point to the limitations of both short-term air samples and settled-dust analysis. The purpose of this presentation is to explore both the value and the limitations of this HVAC filter-based technique as well as to extend the technique to other contaminants including allergens, SVOCs, viruses, and radionuclides. Issues of sensitivity, particle size associations, compositional changes in the dust while the filter is installed, and inhibition of DNA extraction are all explored. The results of this analysis suggest promise of the technique for many common indoor particles and further that it is most suited to contaminants that are stable and associated with super-micron particles. Systems with a long run-time and high filter efficiency are particularly suitable for this approach.