AAAR 34th Annual Conference
October 12 - October 16, 2015
Hyatt Regency
Minneapolis, Minnesota, USA
Abstract View
Characterizing the In-Situ Size-Resolved Removal Efficiency of Residential and Light-Commercial HVAC Filters for Particle Sizes between 0.01 and 10 Micro-meter
TORKAN FAZLI, Brent Stephens, Illinois Institute of Technology
Abstract Number: 335 Working Group: Control Technology
Abstract The majority of human exposure to airborne particles occurs inside buildings. Higher efficiency particle air filtration in heating, ventilating, and air-conditioning (HVAC) systems is increasingly being relied upon to reduce indoor exposures to particulate matter, but most filtration rating systems evaluate the particle removal efficiency of filters only for particles 0.3–10 micro-meter in diameter. Because the vast majority of particles in indoor environments (by number) are smaller than 0.3 micro-meter in size, including ultrafine particles (UFPs: particles less than 0.1 micro-meter), our current filtration rating systems fail to address a key portion of indoor aerosols. Therefore in this project, an in-situ test method is used to measure the particle removal efficiency of a wide range of commercially available HVAC filters in 28 particle size ranges from 0.01-10 micro-meter in diameter. The test procedure involves measuring particle concentrations upstream and downstream of an HVAC filter installed in a residential air-handling unit in a controlled and unoccupied residential apartment unit. Size-resolved particle removal efficiency is calculated by subtracting the average ratio of downstream-to-upstream pollutant concentrations from unity. A combination of TSI NanoScan SMPS and TSI Optical Particle Sizer are used for this purpose. We also characterize the impacts of filter pressure drop on system airflow rates using a flow plate device. Different filters with various minimum efficiency rating values (MERV) ranging from MERV <5 to HEPA are being tested from a variety of manufacturers. Preliminary results demonstrate that the removal efficiency of filters with MERV <5 ranged from only 0% to 30% for all particle sizes, while the removal efficiency of MERV 8 filters ranged from 0% to 44% for all particle sizes. These data are now being compiled into a database for engineers and exposure scientists to use to improve modeling efforts and decision-making.