Bipolar Ionization: Sometimes the Best Defense is a Good Offense

As people begin to think about their return to “normal” in the wake of COVID-19, many questions remain regarding what can be done to minimize the risk of virus transmission in the office. Of the many solutions, bipolar ionization has promise when it comes to combatting the spread of viruses and can even help reduce your building’s energy usage. Additional clinical studies must be performed outside of the small, controlled testing environments to substantiate manufacturer claims, but how does bipolar ionization work?

The CDC has recently published the main transmission method of COVID-19 to be person-to-person. They define methods of spread to be between people who are in close contact, and through respiratory droplets from infected individuals.

Guidelines on improvements to HVAC systems have been published to help mitigate the risk of virus spread in commercial facilities. These measures, such as increasing filter efficiency and ventilation rates, are quite simple and require minimal modification to existing HVAC systems. While increasing ventilation rates is a proven means of mitigation, a common theme of these suggestions (UV and increased filtration) is that they require the virus to make its way back to a centralized HVAC unit in order to work.

Bipolar Ionization is a means of air quality control in your HVAC system that does not rely on particles making their way back to a centralized air handling unit. It works by generating positively and negatively charged ions inside the airstream and dispersing them into a space. These ions then interact with virus particles, dust, pollen and other VOCs (volatile organic compounds), allowing a filter or mask to entrap them more easily. Bipolar ionization enhances the filter or mask’s effectiveness, but does not rely entirely on them to be effective. Older versions of this technology were known for ozone production, but new “needlepoint” ionization technologies have surfaced that claim to have zero ozone production. ASHRAE’s position paper on the topic refers to these needlepoint ionizers requiring more research, and McKenney’s agrees.

An additional proposed benefit of bipolar ionization is the removal of contaminants from the air we breathe, allowing a potential reduction in ventilated air delivered to a building by leveraging the Indoor Air Quality (IAQ) procedure of ASHRAE Standard 62.1 in lieu of the ventilation rate procedure (VRP). Lowering ventilation rates allows for a reduction in the building ventilation and exhaust systems, as well as a reduction in cooling requirements for your air handling equipment. This may allow for a reduction in first costs and energy savings for your building.

Studies are still being performed to evaluate ionization’s efficacy as it pertains to the COVID-19 virus and McKenney’s will continue to research these new methods and make decisions based on the most current information.

Keep in mind, the absolute best way to mitigate your risk of infection is to socially distance, wash your hands, keep your hands away from your eyes, nose and mouth, and wear masks when appropriate. For additional HVAC guidelines, refer to our April blog post from Rick Dustin.


  1. CDC updates COVID-19 transmission webpage to clarify information about types of spread. May 22, 2020.
  2. The American Society of Refrigeration and Air-Conditioning Engineers (ASHRAE) developed COVID-19 Preparedness Resources and has established the ASHRAE Epidemic Task Force to respond to the current global COVID-19 pandemic and provide guidance on how to prepare for future epidemics. This task force will address the challenges as it relates to the effects of heating, ventilation, and air-conditioning systems on disease transmission in healthcare facilities, the workplace, home, public and recreational environments. The task force will also provide recommendations for setting up temporary field hospitals in convention centers, arenas, and indoor stadia to deal with surges.

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About Ryan Yarborough


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Ryan Yarborough is a Project Engineer in the Engineering Solutions group. He designs mechanical and plumbing systems and is also the Engineering team's healthcare expert. Ryan, a former co-op and Georgia Tech grad, works closely with our project managers to deliver designs that are timely, constructible and sustainable.

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