COVID Solutions for Indoor Air

in Homes, Schools & Businesses

COVID Solutions for Indoor Air

in Homes, Schools & Businesses

empty classroom

Indoor Virus Spread Can Be Dramatically Reduced

In a properly managed environment, COVID transmission can be close to zero.*

* For reference and educational purposes only. Seek the advice of appropriate professionals to choose effective indoor air cleaning systems.

* This site does not offer medical advice and is not anti-vax.

Indoor Virus Spread Can Be Dramatically Reduced

In a properly managed environment, COVID transmission can be close to zero.*

* For reference and educational purposes only. Seek the advice of appropriate professionals to choose effective indoor air cleaning systems.

* This site does not offer medical advice and is not anti-vax.

Improving Indoor Air Quality is the Solution 

It wasn’t until the end of 2021 that public health organizations and the White House fully acknowledged COVID as airborne. Now that it’s official, we can discontinue the ineffective approaches that focused on “droplets.”

COVID aerosol particles are microscopic, travel much farther than droplets, and can hang in indoor air for hours. This is why the virus spreads quickly (and because of more contagious variants), and why distancing indoors does not provide adequate protection. It’s also why the more effective, tighter-fitting KN95 or N95 masks are necessary. 

Proven air-cleaning technologies that focus on Ventilation & Air Filtration need to be implemented to remove COVID particles from indoor air in schools, offices, restaurants, and your home. There’s no 100% guarantee but once spaces are equipped with properly managed ventilation and filtration systems, the air will be far safer to breathe without a mask. 

This is solid science, yet it’s revolutionary because while we have the means, too few schools, businesses, and homes have effectively implemented this. When this technology is properly applied (even the simpler, low-cost options) it can bring us close to normal indoor life. 

ventilation air purification diagram

Masks Might Be Unnecessary for Most People in Buildings with Properly Managed Ventilation & Filtration

Improving Indoor Air Quality is the Solution 

It wasn’t until the end of 2021 that public health organizations and the White House fully acknowledged COVID as airborne. Now that it’s official, we can discontinue the ineffective approaches that focused on “droplets.”

COVID aerosol particles are microscopic, travel much farther than droplets, and can hang in indoor air for hours. This is why the virus spreads quickly (and because of more contagious variants), and why distancing indoors does not provide adequate protection. It’s also why the more effective, tighter-fitting KN95 or N95 masks are necessary. 

Proven air-cleaning technologies that focus on Ventilation & Air Filtration need to be implemented to remove COVID particles from indoor air in schools, offices, restaurants, and your home. There’s no 100% guarantee but once spaces are equipped with properly managed ventilation and filtration systems, the air will be far safer to breathe without a mask. 

This is solid science, yet it’s revolutionary because while we have the means, too few schools, businesses, and homes have effectively implemented this. When this technology is properly applied (even the simpler, low-cost options) it can bring us close to normal indoor life. 

ventilation air purification diagram

Masks May Be Unnecessary for Most People in Buildings with Properly Managed Ventilation & Filtration

Fresh Air Ventilation

open window illustration

Ventilation Systems

ventilation system graphic

Air Filtration/Cleaning

Ultraviolet Disinfection

Ultraviolent disinfection system illustration

The Good News

Air cleaning initiatives are a great investment. Students, teachers, office and retail workers, restaurant staff, and every customer or client will not only be safer from a deadly virus but will also be less likely to come down with a cold or the flu. Allergy and asthma sufferers will feel better in a building with good ventilation and filtration. Imagine reducing personal misery and organizations saving money because of fewer sick days.

 

The Very Good News

Businesses that make their building healthier see a 10% increase in their bottom line. A healthy building is good business.

 

The Superhero Good News

Once in place and properly maintained these systems eliminate most indoor pollutants. The true genius of clean air is that it can future-proof you against any serious impact of every new nasty virus.

children in a classroom raising their hands

The Shift in Responsibility

When we thought the virus spread through droplets, we were personally responsible for keeping others safe. We were required to keep our distance, wear a mask, or isolate.

But with a virus of tiny particles that contaminate a room for hours after an infected person has left, the responsibility is on those who own or manage the indoor space. Just as they are responsible for clean water from their faucets they are responsible for clean air. Of course, individuals should still do their part to not infect others.

children in a classroom raising their hands

The Good News

Air cleaning initiatives are a great investment. Students, teachers, office and retail workers, restaurant staff, and every customer or client will not only be safer from a deadly virus but will also be less likely to come down with a cold or the flu. Allergy and asthma sufferers will feel better in a building with good ventilation and filtration. Imagine reducing personal misery and organizations saving money because of fewer sick days.

The Very Good News

Businesses that make their building healthier see a 10% increase in their bottom line. A healthy building is good business.

The Superhero News

Once in place and properly maintained these systems eliminate indoor pollutants. The true genius of clean air is that it can future-proof you against any serious impact of every new nasty virus.

people working on laptops in an office

The Shift in Responsibility

When we thought the virus spread through droplets, we were personally responsible for keeping others safe. We were required to keep our distance, wear a mask, or isolate.

But with a virus of tiny particles that contaminate a room for hours after an infected person has left, the responsibility is on those who own or manage the indoor space. Just as they are responsible for clean water from their faucets they are responsible for clean air. Of course, individuals should still do their part to not infect others.

Indoor Ventilation

Principles developed by engineers and physicists

Ventilation Replaces Indoor Air with Fresh Outdoor Air

Air Exchange is the key concept.

The infographic provides ventilation instructions.    

IMPORTANT:
DO NOT recirculate the air – that’s worse than doing nothing.
Recirculating air (blowing it around the room) does not clean the air and can cause infection by blowing infected particles directly at people.

Create a Cross Current

For effective air exchange, face one window fan to pull in outside air and another fan in a window across the room or in another room to blow indoor air out.

Prevent Airborne Disease INFOGRAPHIC by Sergio Coscolín

Infographic by @SergioCoscolin

If you use a Ceiling Fan IT MUST BE SET to PULL the Air UP (turning clockwise) to pull air UP and AWAY from people.

Floor Fans or Box Fans Should Always Point AWAY from People to avoid blowing contaminated air directly at them.

Ventilation Replaces Indoor Air with Clean Fresh Outdoor Air

Air Exchange is the key concept.

The infographic provides ventilation instructions.    

IMPORTANT:
DO NOT recirculate the air – that’s worse than doing nothing.
Recirculating air (blowing it around the room) does not clean the air and can cause infection by blowing infected particles directly at people.

Create a Cross Current

For effective air exchange, face one window fan to pull in outside air and another fan in a window across the room or in another room to blow indoor air out.

Prevent Airborne Disease INFOGRAPHIC by Sergio Coscolín

If you use a Ceiling Fan IT MUST BE SET to PULL the Air UP (turning clockwise) to pull air UP and AWAY from people.

Floor Fans or Box Fans Should Always Point AWAY from People to avoid blowing contaminated air directly at them.

Improving School Air Quality:
The Basics & a Case Study:

This is an excellent overview of clean indoor air technology. Ventilation, Air Filtration, and Air Quality Monitoring are explained as part of a school case study. Effective low-budget options are also offered.

For Technical Details
About Monitoring Air Quality:

David Elfstrom talks about Ventilation. Dr. Poppendieck discusses measuring air quality with CO2 Monitors. See videos lower on this page for how to build Corsi-Rosenthal Boxes & simpler CO2 Monitor explanation.

Improving School Air Quality: The Basics
& a Case Study:

This is an excellent overview of clean indoor air technology. Ventilation, Air Filtration, and Air Quality Monitoring are explained as part of a school case study. Effective low-budget options are also offered.


Technical Details for
Monitoring Air Quality:

David Elfstrom on Ventilation and Dr. Poppendieck discusses measuring air quality using CO2 Monitors.

See videos below for how to build Corsi-Rosenthal Boxes and a simpler explanation of CO2 Monitors.

Air Filtration

Filtering Out Viruses with HEPA Filters

Air Filtration is Used With or Without Ventilation

There are numerous ways to filter indoor air. Large buildings use state-of-the-art HVAC systems while homes use portable HEPA air cleaners. There are many high-quality brands available for home use.

Portable Air Cleaners for Classrooms, Offices & Homes

The difference between the models of any brand is mostly the square footage they cover. Make sure the air cleaner you purchase has a HEPA 13 filter, which is medical grade and will remove 99.95% of all particles in the air measuring 0.2 microns in diameter particles (which will remove the COVID virus). The CleanAirCrew Air Cleaner buying guide page is a good place to start your research.

Air Filtration is Used With or Without Ventilation

There are numerous ways to filter indoor air. Large buildings use state-of-the-art HVAC systems while homes use portable HEPA air purifiers.

There are many high-quality brands available for home use. The difference between the models of any brand is mostly the square footage they cover. Make sure the purifier you purchase has a HEPA 13 filter, which is medical grade and will remove 99.95% of all particles in the air measuring 0.2 microns in diameter particles (which will remove the COVID virus). The CleanAirCrew Air Cleaner buying guide page is a good place to start your research.

Corsi-Rosenthal Boxes - DIY Air Filters

Effective Air Cleaners Almost Anyone Can Build

 

Student Builds Corsi-Rosenthal Boxes in School Colors!

 

Building Corsi-Rosenthal Boxes – Richard Corsi

 

Even This Old House Builds One

The CleanAirCrew website is a great resource.

It has full instructions for building the Corsi-Rosenthal Box

Monitoring Air Quality

CO2 Monitors give you the ability to assess air quality. They don’t measure the amount of COVID in a room, but tell you the quality of your ventilation by measuring the levels of CO2 in an indoor space.

This 3-minute video explains the use of CO2 Monitors:

You can use a CO2 Monitor to assess air quality in a room, a restaurant, an airplane, or any indoor space.

The CleanAirCrew website has CO2 Monitor information.

Tweet about Peterborough Ontario library lending CO2 monitors

A local library in Ontario lends CO2 Monitors for measuring the quality of the ventilation in a room.

Indoor Humidity

Reduces Virus Particles & Increases Body's Defenses

Humidity Makes Indoor Air Safer

After ventilation and filtration, proper indoor humidity can reduce the number of viral particles in the air by half, because the moisture causes many virus particles to land on surfaces.

humidifier on table next to laptop in front of a couch
humidifier on table with steam coming out

The Ideal Humidity Level is 40–60%

Humidity “can support increased viral particle deposition, as well as support our bodies’ natural defense mechanisms by reducing the drying of our mucus membranes.” – Dr. Van Den Wymelenberg 

 

Humidity Makes Indoor Air Safer

After ventilation and filtration, proper indoor humidity can reduce the number of viral particles in the air by half, because the moisture causes many virus particles to land on surfaces.

humidifier on table next to laptop in front of a couch

The Ideal Humidity Level is 40–60%

Humidity “can support increased viral particle deposition, as well as support our bodies’ natural defense mechanisms by reducing the drying of our mucus membranes.” – Dr. Van Den Wymelenberg 

humidifier on table with steam coming out

Health Organizations & The White House See the Light

After two years of an outdated theory, aerosols are finally recognized as the true culprits

COVID and Clean Indoor Air – Discussion with the experts hosted by The White House Office of Science & Technology Policy

This video of the March 29, 2022 virtual conference included presentations by experts in airborne virus transmission and clean air solutions.

It wasn’t until March 23, 2022, that the White House released its first statement acknowledging COVID to be airborne. Overdue but the administration is now promoting a focus on cleaning indoor air. 

Engineer Linsey Marr explained aerosol science – how the particles move around and accumulate. She introduced the primary air-cleaning solutions.

Joseph Allen, healthy building specialist, explained how they keep students and employees healthier, and happier. And save money because people are more productive and don’t miss classes or work due to illness.

Dr. Zeynep Tufekci did not mince words as she reminded us that public health officials denied the aerosol transmission of COVID for 2 years despite the findings of aerosol engineers.

Dr. Zeynep Tufekci did not mince words as she reminded us that public health officials denied the aerosol transmission of COVID for 2 years despite the findings of aerosol engineers.

Here’s The White House statement from March 23, 2022 that explains how Ventilation & Air Filtration can reduce the transmission of COVID. Many people are unaware of it. One reason this site was created.

Tweet about White House clear the air COVID statement 3-23-22

The EPA’s Indoor Air Challenge

  • Assess Indoor Air Quality (IAQ)
  • Create an action plan for clean indoor air
  • Optimize fresh air ventilation with HVAC system and exhaust fans
  • Enhance air filtration using central HVAC system and portable air cleaners
  • Get your community engaged in your action plan – educate and get buy-in
Corsi-Rosenthal Box - DIY air filtration

Articles About Decreasing COVID Using Air-Cleaning Technology 

Better Ventilation in Schools Could Reduce COVID Risks & Boost Learning - May 13, 2022

Better Ventilation in Schools Could Reduce COVID Risks by Public Health Reporter Jonathan Lambert

Biden Administration (finally) Elevates Healthy Buildings as Part of COVID Strategy

Biden administration (finally) elevates healthy buildings as part of national Covid strategy by Joseph Allen

This Invisible Covid-19 Mitigation Measure is Finally Getting the Attention it Deserves - April 10, 2022

This Invisible Covid-19 Mitigation Measure is Finally Getting the Attention it Deserves -April 10, 2022

Italian Study Shows Ventilation Can Cut School COVID Cases by 82%

Italian Study – Ventilation Can Cut School COVID Cases by 82%

Erie County to Buy Air Purifiers for 11,000 School Classrooms - April 7, 2022

Erie County to Buy Air Purifiers for 11,000 School Classrooms – April 7, 2022

US, WHO Officials and Experts Agree (sort of) on How COVID-19 Spreads - April 8, 2022

US, WHO Officials and Experts Agree (sort of) on How COVID-19 Spreads – April 8, 2022

Biden Administration Launches Effort to Improve Ventilation & Reduce the Spread of COVID-⁠19 in Buildings

Biden Administration Launches Effort to Improve Ventilation & Reduce the Spread of COVID-19 in Buildings

What the CDC Guidelines Don’t Say About Classroom Ventilation and COVID-19 Spread - Feb. 17, 2021

Did the CDC downplay school ventilation because of lack of understanding or simple disregard? Feb. 17, 2021

The EPA Clean Air in Buildings Challenge - March 2022

The EPA Clean Air in Buildings Challenge – March 2022

Articles About Decreasing COVID Using Air-Cleaning Technology 

Better Ventilation in Schools Could Reduce COVID Risks & Boost Learning - May 13, 2022

Better Ventilation in Schools Could Reduce COVID Risks by Public Health Reporter Jonathan Lambert

Biden Administration (finally) Elevates Healthy Buildings as Part of COVID Strategy

Biden administration (finally) elevates healthy buildings as part of national Covid strategy by Joseph Allen

This Invisible Covid-19 Mitigation Measure is Finally Getting the Attention it Deserves -April 10, 2022

This Invisible Covid-19 Mitigation Measure is Finally Getting the Attention it Deserves -April 10, 2022

Italian Study Shows Ventilation Can Cut School COVID Cases by 82%

Italian Study – Ventilation Can Cut School COVID Cases by 82%

Erie County to Buy Air Purifiers for 11,000 School Classrooms - April 7, 2022

Erie County to Buy Air Purifiers for 11,000 School Classrooms – April 7, 2022

US, WHO Officials and Experts Agree (sort of) on How COVID-19 Spreads - April 8, 2022

US, WHO Officials and Experts Agree (sort of) on How COVID-19 Spreads – April 8, 2022

Biden Administration Launches Effort to Improve Ventilation & Reduce the Spread of COVID-⁠19 in Buildings

Biden Administration Launches Effort to Improve Ventilation & Reduce the Spread of COVID-19 in Buildings

What the CDC Guidelines Don’t Say About Classroom Ventilation and COVID-19 Spread - Feb. 17, 2021

Did the CDC downplay school ventilation because of lack of understanding or simple disregard? Feb. 17, 2021

The EPA Clean Air in Buildings Challenge - March 2022

The EPA Clean Air in Buildings Challenge – March 2022

Ventilation When Driving

Horse-drawn Carriage

The safest transportation for avoiding COVID.

A car is a small enclosed space and poses a greater risk than your home, especially with closed windows.

Remember –
Don’t Re-circulate the Air! Bring in Outside Air!

“Driving with the windows up and the air conditioning or heat on is the worst scenario.” – Brown University

Opening Windows for 10 seconds Reduces the Build-up of COVID Particles by 97%

Open windows on the opposite side of the car from where people are sitting to create a diagonal airflow.

  • Under 30 mph, have all windows open. 
  • At higher speeds, occasionally open a front window and the opposite rear window for 10 seconds. 

Sitting in the Front is Safer

Aerosols get trapped in the back, so put high-risk passengers in the front. – BBC


Masking in a Car is the Safest – But Ventilate!

A car is a small enclosed space, posing a greater risk than your home especially with closed windows.

Remember –
Don’t Re-circulate the Air! Bring in Outside Air!

“Driving with the windows up and the air conditioning or heat on is the worst scenario.” – Brown Study


Opening Windows for 10 seconds Reduces Build-up of COVID Particles by 97%

Open windows on opposite sides of the car from where people are sitting for a diagonal airflow.

Sitting in the front is safer.  Aerosols get trapped in the back, so put high-risk passengers in the front. – BBC Report 

Masking in a Car is the Safest – But Ventilate!

Horse-drawn Carriage

The safest transportation for avoiding COVID.

white car parked

But if you drive a car follow the guidelines.

The Portable Air Cleaner* That I Use

I started at the CleanAirCrew Air Cleaner buying guide page that I mentioned above but I found that it took some time to sift through all the great info.

As I stated, the difference between the models of each brand is essentially how big of an area the air cleaner will cover, as well as how fast it will clean that area. You’ll need one with a HEPA 13 filter to remove the COVID virus particles.

I gathered information from a few different sources and read a lot of reviews to find the ideal portable air cleaner for my home.

I chose Medify Air

* I originally used the common term “air purifier” on this site until I read environmental engineer, Dr. Shelly L. Miller’s comment on her website “please don’t call them air purifiers, we can’t ever purify the air – what does that even mean…?” I replaced the term with “air cleaner” for scientific accuracy. 

medify air purifier

Face Masks

The most effective ones to protect against COVID

The CleanAirCrew page on FACE MASKS has everything you need to know, including elastomeric respirators.

face masks

Face masks of various types.

Black Elastomeric Respirators

Please don’t laugh or criticize those who wear this type of respirator. Vulnerable people need protection

face masks

The full range of face masks.

CleanAirCrew page on FACE MASKS including elastomeric respirators.

Christine double-masked

Christine triple-vaxxed
and double-masked

If this page has been
helpful, your support
is appreciated.

If this page has been helpful,
your support is appreciated.

Christine double-masked

Christine triple-vaxxed
and double-masked

If you have expertise in aerosols, ventilation, or air filtration and see something on this page that is inaccurate, please send me a message using this form.

I also welcome comments from anyone else! 

empty classroom
worker at laptop with documents
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