A new laboratory test method for measuring the bioaerosol filtration efficiency of air cleaners

A new laboratory test method for measuring the bioaerosol filtration efficiency of aircleaners is presented. The methodology has been used on test systems operating from 50 cfm to 2,000 cfm with room air cleaners, duct-mounted general ventilation filters, and vacuum cleaner filters. The method defines the selection of the bioaerosol challenges, the means of generating the bioaerosols, the sampling equipment and sampling protocols. The method includes extensive QA/QC to ensure that reliable results are reported. The QA/QC features include replicate sampling, conducting blank tests (in which no filter is installed in the test section) to quantify any upstream to downstream sampling bias in the test rig and/or sampling lines and conducting tests with high efficiency filters (e.g., HEPA filters) test to ensure that zero penetration can be measured. An additional QA/QC specification is the performance of inert-particle tests (using standard ASHRAE test protocols) for solid- and liquid-phase challenges; these results help to optimize the sampling durations for the bioaerosol samplers and the inert filtration efficiencies should be reasonably consistent with the bioaerosol filtration efficiencies.