The Effects of Air Purification Technology on Environmental and Clinical Metrics in Two Healthcare Settings

June 2022  |  Stanislaw P. Stawicki, Alicia R. Urrutia, Kathryn C. Worrilow



Improvements in indoor air quality and overall occupant comfort and health can be achieved by reducing airborne sources of illness and infection. Many facility acquired infections (FAIs) originate from the air. Controlling these airborne pathogens is a priority for building’s facilities teams across industries. An advanced air purification technology (AAPT) was designed to inactivate the DNA and RNA of all bacteria, fungi, and viruses,
rendering them non-infectious. The technology also comprehensively remediates volatile organic compounds (VOCs). This study investigates the effect of AAPT on environmental and clinical metrics in two healthcare settings.

This study represents a post-hoc synthesis of two independent and institutional review board (IRB) approved projects where AAPT operated in an acute care hospital’s medical surgical floor (ACH-MSF) and in a long-term care facility’s (LTCF) memory support clinical unit. The AAPT was installed within each facility’s heating, ventilation, and air conditioning (HVAC) ductwork. The AAPT unit in the ACH-MSF provided comprehensive remediation of all airborne pathogens and the AAPT unit in the LTCF remediated all airborne pathogens and VOCs. In the ACHMSF, three zones were retrospectively studied on two floors: control floor with high efficiency particulate air (HEPA) filtration, mixed HEPA and AAPT remediation, and comprehensive AAPT remediation. In the LTCF, two zones were studied on two floors: control floor with HEPA filtration and comprehensive AAPT remediation. Statistical analyses were run on the hospital data to only include surgical patients (non-bariatric) admitted to any zone with a Case Mix Index (CMI) at discharge. CMI was used to adjust for the severity of illness. The LTCF data analyses included all residents in both zones. The control floor was used as the reference point for both installations. In both facilities, the measured airborne and surface bacterial and airborne fungal levels, and VOC levels decreased as environmental purity increased. The ACH-MSF demonstrated a statistically significant decrease in patient length of stay (39.5%), improved discharge metrics and 23% cost savings. The FAI rate in the LTCF decreased by 39.6% pre- to post-installation. Additionally, clinical staff callouts decreased by 47% in the LTCF. The AAPT significantly reduced levels of infectious airborne and surface pathogens and VOC levels in both healthcare facilities thereby removing two common vectors of illness. Both of the studied facilities experienced improved clinical and economic metrics, with similar size of the observed changes. The comprehensive removal of airborne pathogens in healthcare settings appears to have a direct positive impact on residents and patients, as wells as indirect positive impact on staff. The current findings, encompassing a post hoc analysis of a large combined sample, support the hypothesis that environmental factors impact wellness and can be applied to indoor environments across many industries

This article or paper was published in ASHRAE Transactions, 128, Part 2, June, 2022. Copyright 2022 ASHRAE, Inc. Reprinted by permission at This article may not be copied and/or distributed electronically or in paper form without permission of ASHRAE. For more information about ASHRAE Transactions, visit