AAAR 37th Annual Conference October 14 - October 18, 2019 Oregon Convention Center Portland, Oregon, USA
Abstract View
Impacts of Rooftop Vegetation on HVAC Filter Loadings and Indoor Air Quality
PRADEEP RAMASUBRAMANIAN, Irvan Luhung, Elliott Gall, Portland State University
Abstract Number: 114 Working Group: Indoor Aerosols
Abstract Resuspension of biotic particles from green roof substrate or vegetation on building rooftops may contribute to additional biomass loading on HVAC filters, influencing the quality of ventilation air. For example, volatile organic compounds (VOCs) emitted from biotic material trapped on the filter can subsequently react with ozone or other oxidants entering the ventilation system, resulting in secondary organic aerosol (SOA) or reaction products entering the indoor space. This study investigates the potential for green roofs to impact indoor air quality (IAQ), by investigating the microbiome, emissions, and chemistry occurring due to the particle loadings on HVAC filters near green roofs. HVAC filters were collected from two air handling units (AHUs) at a field site in Portland OR containing both green and white rooftop types. Experiments were conducted to characterize the microbial loading, VOC emissions and byproduct/SOA formation from the filters. The microbiome of the green roof filters (GRF) vs. white roof filters (WRF) were characterized by quantitative polymerase chain reaction (qPCR) and metagenomic sequencing on Illumina HiSeq platform. Primary VOC emissions were identified using proton transfer reaction – time of flight – mass spectrometry (PTR-TOF-MS), measuring the differences in the balance and type of volatile emissions due to loaded mass on GRF vs. WRF. Ozone was then injected upstream the filter, to measure ozone removal due to filter loading and a scanning mobility particle sizer (SMPS), measuring particles 10-420 nm, was placed after the filters to assess the potential for SOA formation due to oxidation processes on the filter. Preliminary measurements indicate differences in filter loadings that could potentially impact the quality of ventilation air.