This could not be farther from the truth.
Air cleaning is additive – not subtractive.
For example – hospitals have excellent air cleaning. In this preprint of a study – “A single bed hospital room equipped with an excellent ventilation rate (∼ 14 air changes per hour) can clear the aerosols in 20 minutes. However, with the addition of two air cleaners, the clearance time became 3 times faster (in 6 minutes and 30 seconds).” Explanation of why .
Don’t forget – the following agencies recommend portable air cleaners.
- CDC directly recommends them: “Use portable high-efficiency particulate air (HEPA) fan/filtration systems to enhance air cleaning (especially in higher risk areas such as a nurse’s office or areas frequently inhabited by people with a higher likelihood of having COVID-19 and/or an increased risk of getting COVID-19).”
- ASHRAE recommends them
- EPA recommends them.
ASHRAE is available to consult with.
They can be emailed COVID-19@ashrae.org