Air Purifiers Destined for Classrooms

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Teams in Infrastructure and Sustainability (I&S) are again on the move, staying one step ahead in virus mitigation measures this fall. More than 200 portable air purifiers will be installed in centrally and departmentally scheduled classrooms ahead of the first day of classes on Monday, Aug. 23. The air purifiers or “scrubbers” improve air quality by decreasing particle volume concentrations within a single room. With classrooms slated for heavier use this semester, the installation of portable air cleaners ensures an additional level of clean air within individual classrooms.

Last August, teams from Environmental Health and Safety (EH&S) and I&S collaborated with Professors Nga Lee (Sally) Ng, Thomas Orlando, and Loren Williams from the College of Sciences and College of Engineering to test several types of air purifying equipment to gauge their effectiveness in removing small air particles. Using a research-grade particle measuring instrument, data was collected over the course of two semesters to determine which air purifier was the most effective in removing particulate from the air.

Data captured from these aerosol studies guided the decision to purchase the BreathSmart 75i HEPA Air Purifier. The BreathSmart unit uses an ozone-safe ionizer to attract air particulate. This particulate is then captured in the high efficiency particulate air (HEPA) filter, thereby significantly reducing the levels of bacteria, allergens, and viruses in the air.

Evaluation of the heating, ventilation, and air conditioning (HVAC) systems in every building on campus is routine at Georgia Tech. I&S ensures indoor ventilation systems on campus meet the American Society of Heating, Refrigerating and Air Conditioning Engineers standards by performing the following preventative maintenance measures:

  • Replacing ultraviolet bulbs in all applicable HVAC systems that are near the end-of-life stage.
  • Using Merv-13 (Minimum Efficiency Reporting Value) filters as an upgrade to existing filters where the HVAC equipment allows.
  • Increasing the fresh air intake and exchange rate in buildings when feasible.

Since the pandemic began, I&S has become accustomed to quickly adapting new mitigation measures. Facility directors and building managers were notified of the addition to the classrooms, and rollout began this week. Purifiers will be placed near the lectern or instructional area and turned on at the beginning of the instructional day and turned off at the end of the day. All packaging and waste from delivery and setup will be collected by the Office of Solid Waste and Recycling and sorted accordingly. Individual area shops will maintain the new units.

The collaboration with researchers and the organized team effort across multiple departments within I&S underscores the Institute’s commitment to the safety and well-being of the campus community.

“Sally Ng’s research students are continuing to monitor aerosol sensors placed in 19 classrooms across campus that provide real-time data on aerosol levels,” said Nazia Zakir, interim vice president of Infrastructure and Sustainability. “Fifteen additional sensors have been procured and will be installed this week to expand our sampling areas and provide additional data. I&S continues to partner with our valued researchers to implement Covid-19 mitigation measures on campus based on proven data and testing.”

For more information on building ventilation and filtration, visit


  • Workflow Status: Published
  • Created By: Kristen Bailey
  • Created: 08/19/2021
  • Modified By: cbrim3
  • Modified: 08/20/2021

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