Conventional vs New Technologies for Evaluating and Validating Engineering Controls through the SARS-CoV-2 Pandemic and Beyond


As the pandemic progressed, an increasing recognition evolved about the role of aerosol transmission and technologies to improve indoor air quality through building ventilation. There are many ways to improve indoor air quality and reduce the risk of viral transmission using existing and proven technologies like air filtration and introducing more outside air. The problem is that these approaches have an energy penalty and cost building operators more money. Thus, the attraction of many new-to-market air purifier devices, or as the CDC calls them “emerging technologies”, such as needlepoint bi-polar ionization (NPBI). To understand if NPBI technology claims translates to real-world as-installed environments in occupied buildings, RHP conducted an internal research study aimed at investigating and replicating installation and performance of an NBPI device.


RHP conducted our own in-house critical review of and a NBPI manufacturer research study and conducted an internal experiment to investigate if energy performance claims translated to real-world as-installed environments in occupied buildings. The assessment was conducted in a constructed realistic sized classroom (20 ft x 40 ft) with a lay-in ceiling and ventilation system. Two ionizers were installed into the ventilation system with each unit rated to handle up to 4,800 CFM of airflow which was sufficient for a room the size of our test chamber. The ion concentrations within the room were monitored at various ventilation conditions to compare with product claims of viral risk reduction.

Management / Policy Implications

The EPA, when asked “Can air cleaning devices that use bipolar ionization, including portable air cleaners and in-duct air cleaners used in HVAC systems, protect me from COVID-19?” states, “This is an emerging technology, and little research is available that evaluates it outside of lab conditions.” Our analysis aligns with this response due to the level of uncertainty between this specific product claim and real-world as-installed environments in occupied buildings. Overall, well-designed and realistic research studies are necessary when evaluating whether “emerging technologies” effectively reduce the risk of COVID-19 transmission and building owners and engineers should evaluate manufacturer claims to understand how product performance claims relate back to real-world conditions.

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