08/09/22: Investigating Air Changes Per Hour: Outside Air, MERV, & HEPA - Does it Add Up?

Recorded on Tuesday, August 9, 2022

Webinar Navigation

Investigating Air Changes Per Hour: Outside Air, MERV, & HEPA - Does it Add Up?

About the webinar:

Air changes per hour (ACH) is the number of times the total air volume in a room or space is completely removed and replaced over the course of one hour. ACH has long been used as a metric to determine how protective ventilation is for spaces like laboratories, TB clinics, airborne infection isolation rooms, and more. In organizations that have used a multi-layered approach to mitigate COVID-19 transmission throughout the pandemic, with a combined population of more than 20,000 employees, COVID-19 transmission has predominantly been traced back to workplaces with an ACH of less than three. This webinar will explorethe combined contributions of outdoor air (OA) dilution, MERV filtration, and Portable Air Cleaning HEPA filters, to determine if the contribution of each is additive, as suggested by ASHRAE, in a Bay Area classroom.

Learning Objectives

At the completion of this activity, the learner will be able to:

  • Describe ACH, existing ASHRAE guidance, and implications for aerosol transmissible diseases and wildfire smoke mitigation

  • Identify ventilation assessment methods to empirically measure the removal of airborne contaminants using outside air, MERV filtered air, and HEPA filtration individually, and in combination

  • Summarize findings from a Bay Area classroom ACH study comparing the decay of carbon dioxide and PM 2.5 to estimates from direct airflow readings

Speaker: David M. Moore, MPH, CIH


David Moore is a Certified Industrial Hygienist, and a graduate of UC Berkeley's Public Health Masters program. He is one dissertation away from a doctorate in public health. He and his life partner began Intrinsic Environment, Health & Safety in 2017, providing scientifically grounded solutions for local businesses, universities, governmental entities, non-profits, addressing some of societies pressing occupational environmental health challenges.

Resources:

PDF icon DMoore_Webinar_08.09.2022_InvestigatingACH
COEH Continuing Education Logo

About COEH:

The Northern Center for Occupational and Environmental Health (COEH) and its sister centers at Los Angeles and Irvine serve government, industry, schools, health professionals, and the general public through programs and partnerships designed to deepen understanding of occupational and environmental hazards and to prevent disease, fatalities, and injuries.