Resources

EPA Testing Shows the Power of DIY Air Filters to Trap Viruses

The results are in: U.S. Environmental Protection Agency research testing of do-it-yourself ‘Corsi-Rosenthal Box’ indoor air filters shows they are 99% effective in removing airborne virus. The 'Owl Force One' device tested by the EPA was built by UConn Indoor Air Quality Initiative researchers with Middletown, Connecticut public school children. The EPA tested a Corsi-Rosenthal […]

Effectiveness of commercial portable air cleaners and a do-it-yourself minimum efficiency reporting value (MERV)-13 filter box fan air cleaner in reducing aerosolized bacteriophage MS2

J. L. Cadnum et al

In an unventilated room, 2 commercial portable air cleaners with HEPA filters and a do-it-yourself box fan air cleaner with MERV-13 filters significantly reduced aerosolized bacteriophage MS2.

Corsi-Rosenthal Boxes with “Used” MERV 13 Filters Can Produce Cleanroom Particle Levels

Jim Rosenthal

Corsi-Rosenthal Boxes can produce extremely low particle counts, whether new or used filters are in place. Air Flow is important, and MERV 13 seems to be just right for capture. The results of using two box filters can result in clean-room level clean air.

Safe even under extreme conditions, says global independent safety science company

Chemical Insights - An Institute of Underwriters Laboratories Inc

The DIY box fan air cleaner operates within acceptable thresholds for market safety standard for electric fans, even under extreme conditions.

Not a fire hazard, says world’s leading insurance broker and risk advisor

Marsh Risk Advisory

Advice from Marsh Risk Advisory: "Corsi Rosenthal boxes are effective in cleaning air inside a classroom." Any cables that are required to power the fan should be taped to the floor to avoid trips. Other risks include students attempting to touch the spinning fan, but the fans do have covers and this is considerered to […]

Tutorial: How to make your own air cleaner at home to protect against fall viruses

CBS News

As COVID cases surge and flu season approaches, Louie Gold demonstrates how to create a DIY air cleaner.

University of Maryland PHABlab

University of Maryland

Dr. Milton’s PHABlab set up a booth where students, alumni, and community members built their own Corsi-Rosenthal boxes at UMD’s Maryland Day

Testing Different Configurations of Do-It-Yourself Portable Air Cleaners

UC Davis

The Corsi-Rosenthal Box Filter “was estimated to perform similarly to residential portable air cleaners that are approximately three times as costly in terms of clean air delivered.”

The Effectiveness of DIY Air Filtration Units

CDC - NIOSH Science Blog

“DIY air filtration units can be an effective means of reducing aerosol exposure. The DIY units reduced aerosol exposure up to 73%”

Science in Action: How to Build a Corsi-Rosenthal Box

UC Davis College of Engineering

Follow Dr Corsi as he shows you how to build your own powerful air cleaner.

Parents call for better air quality in schools to protect against viruses, fire smoke

Toronto Star

Parents call for better air quality in schools

Covid Closed the Nation’s Schools. Cleaner Air Can Keep Them Open.

New York Times

“We would not accept drinking water that is full of pathogens and looks dirty, but we’ve been living with air that is full of pathogens and dirty.”

Research on DIY Air Cleaners to Reduce Wildfire Smoke Indoors

United States Environmental Protection Agency

“DIY) air cleaners, made with a box fan and MERV 13 air filter, are a cost-effective method for reducing smoke concentrations.”

Philly DSA is helping parents build DIY classroom air filters amid school asbestos closures

Safe Air for Philly Schools

Called Corsi-Rosenthal boxes, the makeshift purifiers can also help with mold and other toxins.

Interview with air quality expert Joey Fox

CBC/Radio-Canada

Air quality expert grades the recent results from testing of New Brunswick's schools

Long Covid: Children affected take fight to Downing Street

BBC

"We're hoping the prime minister is going to recognise long Covid in children enough so that he invests in indoor air quality being improved in schools to prevent other children from getting the same condition our children are living with."

Effectiveness of HEPA Filters at Removing Infectious SARS-CoV-2 from the Air

Hiroshi Ueki, Michiko Ujie, Yosuke Komori, Tatsuo Kato, Masaki Imai, Yoshihiro Kawaoka

In southern Arizona, an entire K-8 school tackles dust, COVID-19 with DIY air purifiers

Southern New Mexico Journalism Collaborative

ASU students create DIY air filter

Arizona PBS

For educators, dealing with COVID has required a multi-pronged approach. That includes a DIY air filter. But now, an innovative group of ASU students has gotten creative to protect students in classrooms. Reporter Molly McBride showed us how those filters are made.

Dr Corsi's Bookmark Page of COVID in the media

Richard Corsi

Fresh Air with Ismaila Alfa

CBC Radio Canada

Since January, 15 year old Shiven Taneja has made over 120 D-I-Y air filters to keep particles including COVID-19 droplets out of the air. He and his mom Kavita were recently invited to the 3M factory in Minnesota for a surprise visit.

Covid-related Advocacy Emails to School

Liesl McConchie

Liesl McConchie successfully got a school wide adoption of filter boxes. These are the documents she developed to communicate with interested parties.

Developing a Universiy-Wide Corsi-Rosenthal Box Initiative

Megan Jehn

How to set up a University-Wide Corsi-Rosenthal Box Initiative.

Classroom Filters vs. COVID

ASU News

ASU volunteers builds air filter boxes, which are donated to K–12 schools to help fight COVID-19.

We Need to Improve Indoor Air Quality: Here’s How and Why

Scientific American

Upgrading buildings’ ventilation, filtration and other factors would not only decrease COVID transmission but also improve health and cognitive performance in general.

An ASU epidemiologist and her kids are building DIY air filters to help schools fight COVID-19

KJZZ/Rio Salado College

Lots of parents, teachers and students have found themselves recently with a timely project: making homemade air filters for classrooms and school spaces to help protect from the spread of COVID-19.

Dr Kimberly Prather and Marina Creed presented CRBox "Air Force One" to the White House OSTP

University of Connecticut

A DIY air filtration device assembled by fifth graders in Hartford makes its way to Washington, thanks to a cross-campus effort

UConn Health Hosts “Box-A-Thon” Event For Clean Air

NBC Connecticut

Students from the School of Nursing and Medicine assembled 100 CRBoxes

Clean Air Kits

Affordable Next-Gen Corsi-Rosenthal Box. 5-10x quieter than HEPA purifiers on full. Quickly clear medium to large rooms. Ultra low power. Order as STEM kit or Fully Assembled

The Homemade Air Purifier That’s Been Saving Lives During the Covid-19 Pandemic

Smithsonian Magazine

Made from everyday items found in hardware stores, the Corsi-Rosenthal box is a testament to the power of grassroots innovation.

Testing mobile air purifiers in a school classroom: Reducing the airborne transmission risk for SARS-CoV-2

J. Curtius, M. Granzin & J. Schrod

Staying for 2 h in a closed room with a highly infective person, we estimate that the inhaled dose is reduced by a factor of six when using air purifiers with a total air exchange rate of 5.7 h.

Does Your Kid's Classroom Need An Air Purifier? Here's How You Can Make One Yourself

NPR

A Variation on the “Box Fan with MERV 13 Filter” Air Cleaner

Jim Rosenthal

How it all started, back in 2020.

Can 10× cheaper, lower-efficiency particulate air filters and box fans complement High-Efficiency Particulate Air (HEPA) purifiers to help control the COVID-19 pandemic?

Devabhaktuni Srikrishna

A DIY air purifier that costs under $100 to make is taking America’s classrooms by storm

Fortune

Though Corsi calls it “embarrassingly simple,” the Corsi-Rosenthal box delivers significant reduction in particulate spread in indoor settings.

The best and worst engineering methods to stop COVID

Joey Fox

CO2 monitors & Corsi-Rosenthal Box Instructions

Marija Mladenović Schöpfer and Shiven Taneja

Indoor CO2 concentrations are a proxy to assess building ventilation rates. High CO2 levels represent poor ventilation, indicating that the space does not receive enough outdoor air.

Comment Fabriquer une Boîte Corsi-Rosenthal

Marija Mladenović Schöpfer and Shiven Taneja

French version of the instructions

Como Construir una Caja Corsi-Rosenthal

Marija Mladenović Schöpfer and Shiven Taneja

Spanish version of the instructions

How to Build a Mini Corsi-Rosenthal Box

Marija Mladenović Schöpfer and Shiven Taneja

How to Build a Corsi-Rosenthal Box (UK)

Marija Mladenović Schöpfer and Shiven Taneja

This version of the instructions uses parts available in the UK

Wie Man Eine Corsi-Rosenthal Box Baut

Marija Mladenović Schöpfer and Shiven Taneja

German version of the instructions

How to Build a Corsi-Rosenthal Box (USA)

Marija Mladenović and Shiven Taneja

After three years of covering covid, I built my own air filter

Lena H. Sun

Covid is not going away for the foreseeable future. Vaccination, rapid tests and appropriate masking are important ways to protect against getting sick and spreading the virus. So is better indoor air quality.

White House diverges from CDC, focuses on aerosol COVID spread

CIDRAP News

"It parallels clean water and outdoor air quality. We expect clean water, and we demand pollution be eliminated to make outdoor air clean. Now people will demand clean indoor air quality."

3M scientists: This Corsi-Rosenthal box movement is legit

3M News Center

What can you build with duct tape, air filters, and a box fan? This might sound like the set up for a dad joke, but according to new insights from 3M, the answer is less of a punchline and more a breath of fresh air.

IAQ and Box Fan Filter Build

Theresa Pistochini & Robert McMurry

Presentation

Characterizing the performance of a do-it-yourself (DIY) box fan air filter

Rachael Dal Porto, Monet N. Kunz, Theresa Pistochini, Richard L. Corsi & Christopher D. Cappa

Our results demonstrate that our Corsi-Rosenthal air cleaner efficiently reduces suspended particle concentrations in indoor environments.

A type of simple, DIY air filter can be an effective way to filter out indoor air pollutants

Brown University and Silent Spring Institute

A study from researchers at Brown University and Silent Spring Institute found that inexpensive, easy-to-assemble Corsi-Rosenthal boxes can help reduce exposure to indoor air pollutants.

School of Public Health Builds and Installs Corsi-Rosenthal Air Cleaners

Brown University School of Public Health

Brown University School of Public Health has launched a new health project designed to help combat and mitigate COVID-19: Corsi-Rosenthal Cubes.

COVID-19 and Improving Indoor Air Quality in Schools

California Department of Public Health

Having good ventilation and air filtration in schools is very important to reduce COVID-19 and other diseases that spread through the air. Improving indoor air quality also creates a healthier school environment by limiting exposure to harmful chemicals and wildfire smoke. In addition, better air quality increases student performance and attendance.

Rebuttal Matrix for Advocates of Air Filtration in Schools Based on Common Barriers

Amanda Hu

Version 4. Additions: new concerns addressed, pdf with hotspot links to references. Interactive pdf.

Efficacy of Do-It-Yourself air filtration units in reducing exposure to simulated respiratory aerosols

Raymond C.Derk

This study found that:

COVID-19 Cases By Potential Exposure Location

Illinois Department of Public Health

42% of cases were in schools and colleges

Let’s Clear The Air On COVID

Dr. Alondra Nelson

The most common way COVID-19 is transmitted from one person to another is through tiny airborne particles of the virus hanging in indoor air for minutes or hours after an infected person has been there. While there are various strategies for avoiding breathing that air – from remote work to masking – we can and […]

Do-it-yourself (DIY) air cleaners: Evidence on effectiveness and considerations for safe operation

National Collaborating Centre for Environmental Health

“DIY air cleaners appear to be a valuable, low-cost tool to reduce hazardous PM exposures.”

Impact of do-it-yourself air cleaner design on the reduction of simulated wildfire smoke in a controlled chamber environment

Amara L. Holder et al

This study has shown that DIY air cleaners can be a cost-effective approach to reducing smoke concentrations.

Corsi-Rosenthal Boxes as school-based learning activities

Education Forum

Making health and safety curriculum-friendly

Assessing Mitigation Strategies to Reduce Potential Exposures to Indoor Particle Release Events

Van Valkinburgh, K, et al

Older buildings need innovative retrofit solutions to improve indoor air quality. This study showed that a low-cost unit, made of a simple box fan with a MERV13 filter taped to it may perform as well at removing particles from a room as a high-cost HEPA filter unit.

UMD students, faculty build low-cost air filtration devices

The Diamondback

University of Maryland faculty and students are building and distributing cost-effective air filtration Corsi-Rosenthal boxes.

SARS-CoV-2 indoor air transmission is a threat that can be addressed with science

Jonathan M. Samet et al

Physicist, Non-Profits Build and Test Air Purifiers That Remove COVID Particles

University of Arkansas

"There shouldn’t be anything controversial about clean air. These devices (CR Box Filters) facilitate that. They provide an additional layer of protection that could be widely deployed to make our K-12 and university indoor spaces healthier.”

Airborne transmission of respiratory viruses

Chia C. Wang et al.

Impact of Wildfire Smoke Events on Indoor Air Quality and Evaluation of a Low-cost Filtration Method

Nathaniel W. May et al

MERV-13 filters and box fan is a low-cost alternative to commercial filter units. The Low-cost method effectively filters wildfire PM2.5 and submicron particles.

Ten scientific reasons in support of airborne transmission of SARS-CoV-2

Trisha Greenhalgh et al

Reducing transmission of SARS-CoV-2

Kimberly A. Prather et al

Masks and testing are necessary to combat asymptomatic spread in aerosols and droplets

Installing air filters in classrooms has surprisingly large educational benefits

Vox

“Math scores went up by 0.20 standard deviations and English scores by 0.18 standard deviations” in classrooms fitted with portable air filters compared to those without.

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EPA Testing Shows the Power of DIY Air Filters to Trap Viruses

Effectiveness of commercial portable air cleaners and a do-it-yourself minimum efficiency reporting value (MERV)-13 filter box fan air cleaner in reducing aerosolized bacteriophage MS2

Corsi-Rosenthal Boxes with “Used” MERV 13 Filters Can Produce Cleanroom Particle Levels

Safe even under extreme conditions, says global independent safety science company

Not a fire hazard, says world’s leading insurance broker and risk advisor

Tutorial: How to make your own air cleaner at home to protect against fall viruses

University of Maryland PHABlab

Testing Different Configurations of Do-It-Yourself Portable Air Cleaners

The Effectiveness of DIY Air Filtration Units

Science in Action: How to Build a Corsi-Rosenthal Box

Parents call for better air quality in schools to protect against viruses, fire smoke

Covid Closed the Nation’s Schools. Cleaner Air Can Keep Them Open.

Research on DIY Air Cleaners to Reduce Wildfire Smoke Indoors

Philly DSA is helping parents build DIY classroom air filters amid school asbestos closures

Interview with air quality expert Joey Fox

Long Covid: Children affected take fight to Downing Street

Effectiveness of HEPA Filters at Removing Infectious SARS-CoV-2 from the Air

In southern Arizona, an entire K-8 school tackles dust, COVID-19 with DIY air purifiers

ASU students create DIY air filter

Dr Corsi's Bookmark Page of COVID in the media

Fresh Air with Ismaila Alfa

Covid-related Advocacy Emails to School

Developing a Universiy-Wide Corsi-Rosenthal Box Initiative

Classroom Filters vs. COVID

We Need to Improve Indoor Air Quality: Here’s How and Why

An ASU epidemiologist and her kids are building DIY air filters to help schools fight COVID-19

Dr Kimberly Prather and Marina Creed presented CRBox "Air Force One" to the White House OSTP

UConn Health Hosts “Box-A-Thon” Event For Clean Air

Clean Air Kits

The Homemade Air Purifier That’s Been Saving Lives During the Covid-19 Pandemic

Testing mobile air purifiers in a school classroom: Reducing the airborne transmission risk for SARS-CoV-2

Does Your Kid's Classroom Need An Air Purifier? Here's How You Can Make One Yourself

A Variation on the “Box Fan with MERV 13 Filter” Air Cleaner

Can 10× cheaper, lower-efficiency particulate air filters and box fans complement High-Efficiency Particulate Air (HEPA) purifiers to help control the COVID-19 pandemic?

A DIY air purifier that costs under $100 to make is taking America’s classrooms by storm

The best and worst engineering methods to stop COVID

CO2 monitors & Corsi-Rosenthal Box Instructions

Comment Fabriquer une Boîte Corsi-Rosenthal

Como Construir una Caja Corsi-Rosenthal

How to Build a Mini Corsi-Rosenthal Box

How to Build a Corsi-Rosenthal Box (UK)

Wie Man Eine Corsi-Rosenthal Box Baut

How to Build a Corsi-Rosenthal Box (USA)

After three years of covering covid, I built my own air filter

White House diverges from CDC, focuses on aerosol COVID spread

3M scientists: This Corsi-Rosenthal box movement is legit

IAQ and Box Fan Filter Build

Characterizing the performance of a do-it-yourself (DIY) box fan air filter

A type of simple, DIY air filter can be an effective way to filter out indoor air pollutants

School of Public Health Builds and Installs Corsi-Rosenthal Air Cleaners

COVID-19 and Improving Indoor Air Quality in Schools

Rebuttal Matrix for Advocates of Air Filtration in Schools Based on Common Barriers

Efficacy of Do-It-Yourself air filtration units in reducing exposure to simulated respiratory aerosols

COVID-19 Cases By Potential Exposure Location

Let’s Clear The Air On COVID

Do-it-yourself (DIY) air cleaners: Evidence on effectiveness and considerations for safe operation

Impact of do-it-yourself air cleaner design on the reduction of simulated wildfire smoke in a controlled chamber environment

Corsi-Rosenthal Boxes as school-based learning activities

Assessing Mitigation Strategies to Reduce Potential Exposures to Indoor Particle Release Events

UMD students, faculty build low-cost air filtration devices

SARS-CoV-2 indoor air transmission is a threat that can be addressed with science

Physicist, Non-Profits Build and Test Air Purifiers That Remove COVID Particles

Airborne transmission of respiratory viruses

Impact of Wildfire Smoke Events on Indoor Air Quality and Evaluation of a Low-cost Filtration Method

Ten scientific reasons in support of airborne transmission of SARS-CoV-2

Reducing transmission of SARS-CoV-2

Installing air filters in classrooms has surprisingly large educational benefits