Generated by All in One SEO v5.0.0.1, this is an llms.txt file, used by LLMs to index the site. # Clean Air Crew COVID19 transmission and prevention resources. Airborne transmission, masks, ventilation, filtration, school info, and more. ## Sitemaps - [XML Sitemap](https://cleanaircrew.org/sitemap.xml): Contains all public & indexable URLs for this website. ## Posts - [Posts](https://cleanaircrew.org/posts/) - [Respirators for wildfire smoke](https://cleanaircrew.org/respirators-for-wildfire-smoke/) - Wildfire smoke contains many hazardous elements, including particles and gases. If you can, chose a respirator that can filter both. There are disposable options or elastomeric (rubbery) reusables. - [Masks](https://cleanaircrew.org/masks/) - Resources, links to buy, video review, tools for better fit, how to test for a good seal, and more! Note: We have no financial ties to any of these masks, we just want to help you be protected. We gathered the best information we could find to share with you and your loved ones here. - [Elastomeric Respirators](https://cleanaircrew.org/elastomeric-respirators/) - What are Elastomeric Respirators? They are tight fitting respirators made of synthetic or natural rubber material, can be repeatedly used, disinfected, stored, and re-used.• They are equipped with replaceable filter cartridges or flexible, disc or pancake-style filters,which are not housed in a cartridge body.• They may also have sealing surfaces and adjustable straps that accommodate - [Wildfire smoke safety resources](https://cleanaircrew.org/wildfire-smoke-safety-resources/) - [Kids' Masks](https://cleanaircrew.org/kids-masks/) - How to find protective masks and respirators for children. Kids' disposable and reusable options available. Check out the video review testing various brands! Reusable Masks / Respirators for kids Disposable Masks / Respirators for kids Children's / small faces sizing chart This chart by @parentmishmash is sorted by vertical mask length, but fit based on - [Aranet4 CO2 monitor coupon](https://cleanaircrew.org/aranet4coupon/) - Get an Aranet4 CO2 monitor for $186.75 at Naltic.com/Aranet4Coupon.html using coupon code "IAQ4dad" to help determine if an indoor space is well ventilated, to assess levels of COVID risk. - [Ventilation](https://cleanaircrew.org/ventilation/) - SARS-CoV-2, the virus that causes Covid-19, can float in the air like smoke. Aerosolized particles can linger in poorly ventilated indoor spaces, spreading farther than 6 feet from its source. We need to think about controlling the source of the virus indoors, about ventilation (mixing more outdoor air with indoor air), and about air filtration and cleaning - [Homeschool resources - links](https://cleanaircrew.org/homeschool-resources-links/) - Resources: Homeschool Parents Home Educators Resource Directory (resources for the Home Educator) National Home Education Research Institute Cathy Duffy Homeschool Curriculum Reviews Learn In Freedom (an educational resource site for independent learners) Family Unschoolers Network Jon’s Homeschool Resource Page Learn Out Loud Free Learning Guide (links to free audio books, lectures and podcasts) Gifted Homeschoolers - [Homeschool Resources](https://cleanaircrew.org/homeschool-resources/) - Many families are choosing to homeschool this year, many for the first time. There is a collection of homeschooling resources here, originally published on villagehome.org and is republished here to assist families considering homeschooling For resources and commentary, this twitter thread by a seasoned homeschooler may be helpful. Note: Don't let this overwhelm you. You - [Someone in my home has COVID. How do we isolate safely?](https://cleanaircrew.org/someone-in-my-home-has-covid-how-do-we-isolate-safely/) - When someone in your household needs to quarantine at home, you want them to be isolated from others as much as possible. Remember that the virus transmits predominantly through the air, so sanitizing surfaces is not enough. See the PDF below for tips on how to reduce the risk of transmission from one household member - [DIY box fan filters - Corsi-Rosenthal box](https://cleanaircrew.org/box-fan-filters/) - Also known as a Corsi-Rosenthal box, this DIY method of building your own air filter with MERV13 furnace filters and a box fan are an easy and cost-effective way to help clear indoor air from airborne virus particles, wildfire smoke, pollen, dust, and more! If you can seal a box, you can build one (or - [How to clean the air from harmful wildfire smoke](https://cleanaircrew.org/how-to-clean-the-air-from-harmful-wildfire-smoke/) - Mitigate against wildfire smoke with N95 respirators, HEPA or MERV13 air filters, and tracking air quality near you. - [Personal Air Filters](https://cleanaircrew.org/personal-air-filters/) - Sometimes we need to bring our own air filters. #BYOHEPA These portable solutions will not clean entire spaces well enough to drop other precautions like masking. The physics of air movement make it difficult to recommend reliance on a personal air filter for safety, as blowing clean air can bring some contaminated air with it. - [COVID is Airborne](https://cleanaircrew.org/covid-is-airborne/) - A growing collection of evidence and resources discussing the airborne nature of the SARS-CoV-2 virus, its impacts, and mitigation strategies. Here are the simple facts: A. The SARS-CoV-2 virus travels in air. This is true for many/most respiratory viruses. (reference) B. Infectious virus exists in small sized aerosol particles which can remain suspended and infectious - [UConn](https://cleanaircrew.org/uconn/) - UConn Health Rallying Community to Stop Spread of COVID-19 December 29, 2021 | Kim Krieger - UConn Communications "COVID-19 transmits more easily in overcrowded and poorly ventilated places. To address this, UConn Health has united the UConn community to kick off an Indoor Air Quality Initiative, building inexpensive do-it-yourself air purifiers as part of a pilot project to - [Social Media](https://cleanaircrew.org/social-media/) - Follow us on social media! Twitter Mastodon Facebook YouTube Instagram Pinterest - [CO2 monitors](https://cleanaircrew.org/co2/) - CO2 monitors measure the amount of Carbon Dioxide in the air, and can help determine if an indoor space is well ventilated. Carbon dioxide levels reflect COVID-19 risk: Research confirms value of measuring carbon dioxide to estimate infection risk "Infectious people exhale airborne viruses at the same time as they exhale carbon dioxide. That means - [Portable Air Cleaner (HEPA filter) buying guide](https://cleanaircrew.org/air-cleaners/) - Buying guides by Air Quality expert Marwa Zaatari (includes room size, noise level and cost) the California Air Resources Board (CARB), Association of Home Appliance Manufacturers (AHAM) and a DIY option with a box fan and MERV13 filters! - [The Corsi/Rosenthal Box Hall of Fame](https://cleanaircrew.org/the-corsi-rosenthal-box-hall-of-fame/) - These are pictures of each tweet of someone who has built a CR Box, and all are linked to the actual tweet. This is by design so that you can click on the tweet, and ask any questions you might have directly of them. Such as, "What is the name of that contact paper?" This - [THE Corsi/Rosenthal Box FAQ](https://cleanaircrew.org/boxfanfilterfaq/) - Answers to the most frequently asked questions regarding the DIY box fan air filter solution, also known as the Corsi-Rosenthal box. - [COVID safety at the dentist / orthodontist](https://cleanaircrew.org/covid-safety-at-the-dentist-orthodontist/) - We know that wearing a good N95 respirator is a great way to significantly reduce risk of catching airborne viruses like SARS CoV2 / COVID. However, some situations necessitate mask removal for care. How can we reduce our risk at the dentist or orthodontist? Clean Indoor Air Protections A patchwork of policies across states and - [Dentec](https://cleanaircrew.org/dentec/) - Authorized distributors (as supplied by Dentec) United States: Online Ordering Capabilities: Critical Tool: https://www.criticaltool.com/search/dentec#page_no=1* Dentec® 400NxMD White N95 without Exhalation Valvehttps://www.criticaltool.com/style/dentec-400nxmd-white-n95-without-exhalation-valve-each?PMSRCH=dentec (includes filters) Dentec® 400NxMD Half Mask without Exhalation Valve Complete with P100 Cartridges (white)https://www.criticaltool.com/style/dentec-400nxmd-half-mask-without-exhalation-valve-complete-with-p100-cartridges-each?PMSRCH=dentec Dentec® 400Nx Black Half Mask without Exhalation Valve Complete with P100 Cartridgeshttps://www.criticaltool.com/style/dentec-400nx-black-half-mask-without-exhalation-valve-complete-with-p100-cartridges-each?PMSRCH=dentec Project N95: Black, White, and filter sets: https://www.projectn95.org/brand/comfort-airr - [CO2 Tracker App](https://cleanaircrew.org/co2-tracker-app/) - This app, developed by Alexander Riccio, provides a way for people to upload CO2 measurements tied to places where they were taken, and for users to view the measurements taken by others. CO2 is a fairly good proxy for indoor air quality, and indoor COVID risk. By measuring CO2 indoors, we can estimate how much - [Lunch safety](https://cleanaircrew.org/lunch-safety/) - Kids can wear the most protective masks to school, but when it comes to lunch time, and the masks come off, how do you keep kids safe? #EatOutside and more recommendations. Dr Alex Huffman's thread on eating outside for lunch / meals / snacks. This school in Arlington, VA eats outside. @HeidiNBC "Does this cost - [Support CleanAirCrew.org](https://cleanaircrew.org/support/) - The best way you can support this work is to please share it with your friends, family, co-workers, employers, schools, health care workers, elected officials, facebook friends, tweeps, tiktokers, everybody! The sooner we all understand how to truly keep ourselves safer from the COVID-19 pandemic, the sooner we can end it. Follow us on twitter - [Air filters work - EPA, CDC, OSHA, ASHRAE, and more agree.](https://cleanaircrew.org/air-filters-work/) - We know that HEPA and MERV13 filters work to remove airborne virus particles. Read all about it from the EPA, CDC, OSHA, and ASHRAE. EPA: United States Environmental Protection Agency Air Cleaners, HVAC Filters, and Coronavirus (COVID-19)www.epa.gov/coronavirus/air-cleaners-hvac-filters-and-coronavirus-covid-19 "When used properly, air cleaners and HVAC filters can help reduce airborne contaminants including viruses in a building - [Indoor Air Quality Fact Sheet Series](https://cleanaircrew.org/indoor-air-quality-fact-sheet-series/) - The Center for Green Schools at U.S. Green Building Council has released a unique series of fact sheets about indoor air quality (IAQ), designed to help people without a technical background understand some of the more complicated details. "To protect against COVID-19, schools have implemented many measures recommended by public health professionals: distancing, cohorts, masking, hand-washing, and vaccination. These - [Fit testing at home methods](https://cleanaircrew.org/fit-testing/) - Some low cost options to test your mask / respirator for a good fit. (This is different from the user seal check that you should do every time you put it on to ensure a good seal is formed with no gaps or leaks) Nebulizer method Based on the US ARMY method, you can do - [Expert forum: #DeltaSchoolsAirborne](https://cleanaircrew.org/delta-schools/) - A comprehensive crash course in COVID school safety! Session 1: How is COVID-19 transmitted and how can we protect kids, teachers, staff, families? Dr. Kimberly Prather, Dr. Denise Dewald, Dr. Linsey Marr, Dr. Richard Corsi, David Elfstrom, Dr. Dustin Poppendieck, Jim Rosenthal, Dr. Robert "Chip" T. Schooley, Dr. Howard Taras, Ian Ricksecker Session 2: Update - [Schools](https://cleanaircrew.org/schools/) - COVID safety in schools: A growing collection of resources. Comprehensive Webinar Aug 18, 2021Delta Concerns of U.S. School Reopenings and Reducing Airborne Transmission #DeltaSchoolsAirborne Organize and find more resources at www.worldhealthnetwork.global/resources Printables, advocacy, petitions, and more! More details on this webinar - speakers, shortened video clips, slides and agenda Video: How to effectively ventilate classrooms using - [How to improve masking behavior](https://cleanaircrew.org/masking-behavior/) - by Noelle Tankard MPhil Human Evolutionary Studies, University of Cambridge. BA Archaeology & Anthropology, University of Bristol. Tips for improving masking behavior, and understanding some potential barriers and solutions. Mask Training If you’re new to mask wearing, especially long-time duration mask wearing during strenuous physical activity, or getting used to a new mask: Be patient - [Dr Alex Huffman's airborne aerosols spreadsheet](https://cleanaircrew.org/dralex/) - Dr Alex Huffman's Resource page (google sheet) on COVID transmission & prevention (focus: airborne aerosols) now: ☑️790+ media articles ☑️340+ science papers ☑️videos; infographics; webinars; threads; tools ☑️scientists & more - [The Professors' FAQs on Protecting Yourself from COVID-19 Aerosol Transmission](https://cleanaircrew.org/faq-aerosols/) - https://tinyurl.com/FAQ-aerosols Written by scientists and engineers with many years of collective research experience related to indoor air quality, aerosol science, aerosol disease transmission, and engineered control systems for aerosols. Professors Linsey Marr, Shelly Miller, Kimberly Prather, Charles Haas, William Bahnfleth, Richard Corsi, Julian Tang, Hartmut Herrmann, Krystal Pollitt, Javier Ballester, Jose-Luis Jimenez The contributors are active ## Pages - [Home](https://cleanaircrew.org/) - COVID19 transmission and prevention resources. Airborne transmission, masks, ventilation, filtration, school info, and more. - [Test home slider](https://cleanaircrew.org/test-home-slider/) - Featured Articles Popular Articles How to build a DIY air filter with a box fan, tape, and MERV13 filters - CorsiRosenthal Box COVID and pregnancy How can increased ventilation rates increase school district income? Can COVID cause erectile dysfunction? Is asymptomatic transmission rare or common? Newest Articles How has COVID-19 contributed to homelessness? How is - [Frequently Asked Questions](https://cleanaircrew.org/faq/) - FAQ - Frequently Asked Questions Search for answers or browse our knowledge base. Submit a question COVID effects Where can I find COVID / LongCOVID studies? Health effects COVID and pregnancy Can COVID cause erectile dysfunction? Societal effects Is COVID-19 a national security threat? Is COVID-19 contributing to labor shortages? Is COVID-19 affecting fertility rates? - [Contact](https://cleanaircrew.org/contact/) - Contact us! Would you like to share something with us? Tag us on twitter @CleanAirCrewOrg or use this form to send us an email. Please enable JavaScript in your browser to complete this form.Name *Email *Message *MessageSend Message - [Test page](https://cleanaircrew.org/test-page/) - a Cómo construir unos filtros de aire de bajo costo? Recursos aquí! Permalink Translations by Emily Barnes Franklin – thank you! Click here to go back to all FAQ’s. Click here to go back to all FAQ’s. Did you find this FAQ helpful? facebook twitter linkedin pinterest email Back to Top a I can’t bring in an - [Home - Nederlands](https://cleanaircrew.org/home-nederlands/) - [Home - Svenska](https://cleanaircrew.org/home-svenska/) - [Home - Español](https://cleanaircrew.org/home-espanol-2/) - [Home - עברית](https://cleanaircrew.org/home-עברית/) - [Home - Português](https://cleanaircrew.org/home-portugues/) - [Home - Français](https://cleanaircrew.org/home-francais/) - [Home - Italiano](https://cleanaircrew.org/home-italiano/) - [Home - 日本語](https://cleanaircrew.org/home-日本語/) - [Home - Español](https://cleanaircrew.org/home-espanol/) - [Home - Deutsch](https://cleanaircrew.org/home-deutsch/) - [Search Results](https://cleanaircrew.org/search_gcse/) - [wp_google_search] ## FAQ - [Where can I find COVID / LongCOVID studies?](https://cleanaircrew.org/faq/where-can-i-find-covid-studies/) - LitCovid www.ncbi.nlm.nih.gov/research/coronavirus LitCovid is a curated literature hub for tracking up-to-date scientific information about the 2019 novel Coronavirus. LitCovid is the most comprehensive resource on the subject, providing a central access to 441,472 (and growing) relevant articles in PubMed. The articles are updated daily and are further categorized by different research topics (e.g. transmission) and geographic locations. Long Covid - [Is COVID-19 contributing to labor shortages?](https://cleanaircrew.org/faq/is-covid-19-contributing-to-labor-shortages/) - CDC: Research Says Long Covid “Contributing” to Labor Shortage About 18% of those with Long COVID have not returned to work for over a year. The CDC says it's "hurting the U.S. economy." Long Covid could cost the economy billions every year Working days lost to long Covid could be costing the economy billions of - [How has COVID-19 contributed to homelessness?](https://cleanaircrew.org/faq/how-has-covid-19-contributed-to-homelessness/) - First They Got Long Covid. Then, It Made Them Homeless It's estimated that millions of Americans have developed chronic illness as a result of Covid-19 infection. For some — especially those in the gig economy — it's made them unable to support themselves. “Unfortunately, for much of America, living with long Covid is enough to put folks - [How is COVID-19 affecting schools?](https://cleanaircrew.org/faq/how-is-covid-19-affecting-schools/) - The substitute teacher shortage: Research reveals why it warrants more news coverage "Teacher absenteeism has surged in U.S. public schools since the start of the COVID-19 pandemic and, with it, demand for substitute teachers." Teacher absences driving $18M public school board deficit: Officials "Since the COVID pandemic began in 2020, educator absences have become a - [Is COVID-19 affecting fertility rates?](https://cleanaircrew.org/faq/is-covid-19-affecting-fertility-rates/) - The pandemic’s untold fertility story Long COVID is snuffing out some patients’ dreams of having children, sharpening the pain of loss, grief and medical neglect. Emerging evidence suggests long COVID can affect women’s menstrual cycles, ovarian health and fertility, while studies of related and overlapping conditions like ME/CFS, POTS and connective tissue disorders show female - [Is COVID-19 a national security threat?](https://cleanaircrew.org/faq/is-covid-19-a-national-security-threat/) - United States One in four healthy young Marines report long-term physical, cognitive, or psychiatric effects after mild COVID-19 The study suggests that SARS-CoV-2 infection may negatively affect the health of a significant proportion of young adults. Young adults who experience only mild or no symptoms of SARS-CoV-2 infection may still experience long-term effects of COVID-19, - [Are we still in a COVID-19 pandemic?](https://cleanaircrew.org/faq/are-we-still-in-a-covid-19-pandemic/) - Yes. The World Health Organization's December 2024 epidemiological update states: "Now, we enter the sixth year of the pandemic" (pg 34) www.who.int/publications/m/item/covid-19-epidemiological-update---24-december-2024 "While the U.S. remains in a federal public-health emergency free zone, a leader at the World Health Organization voiced concerns on X (formally known as Twitter) about where the world stands at this stage in - [How do I chose an air filter?](https://cleanaircrew.org/faq/how-do-i-chose-an-air-filter/) - Check out the Portable Air Cleaner (HEPA filter) buying guide here for some resources, what to look for, and what to avoid. - [What's happening with bird flu H5N1?](https://cleanaircrew.org/faq/whats-happening-with-bird-flu-h5n1/) - [COVID and pregnancy](https://cleanaircrew.org/faq/covid-and-pregnancy/) - 1 "All 68 placentas had fibrin deposition & villous trophoblast necrosis" • Placental Tissue Destruction & Insufficiency from COVID-19 Causes Stillbirth & Neonatal Death from Hypoxic-Ischemic Injury • June 1, 2022 2 "SARS-CoV-2 targets blood vessel-comprising endothelial cells, neurons, glia, and choroid plexus cells in the fetal brain" • Fetal Brain Vulnerability to SARS-CoV-2 Infection - [Does airborne SARS-CoV-2 stay infectious longer in unventilated spaces?](https://cleanaircrew.org/faq/does-airborne-sars-cov-2-stay-infectious-longer-in-unventilated-spaces/) - According to research from Allen Haddrell et al., yes. "A significant increase in SARS-CoV-2 aerostability results from a moderate increase in the atmospheric carbon dioxide concentration (e.g. 800 ppm)." The aerosolized virus remains infectious for a longer period of time in a space with higher CO2 concentrations. This again underscores the importance of CO2 monitoring - [CRbox FAQ](https://cleanaircrew.org/faq/crbox-faq/) - Please see the extensive CRbox FAQ page here, including how to build various versions of this DIY air filter, how to overcome objections to use of air filters, safety, implementation, and even lesson plans. - [How do N95 respirators work?](https://cleanaircrew.org/faq/how-do-n95-respirators-work/) - WIRED: The Physics of the N95 Face Mask - [Which masks/ respirators fit small faces (including kids?)](https://cleanaircrew.org/faq/which-masks-respirators-fit-small-faces-including-kids/) - Some options to try are FloMask Kids (reusable elastomeric)KimTech small N95Halyard fuildshield SmallBlox duckbillGerson duckbillJackson N95 / Kimtech regular3M VFlex small 9105s More options in this excellent chart by @ParentMishmash including some ideas of what will fit relative to other masks you may have tried. Source tweet - [Why can you smell a fart in an N95 respirator mask?](https://cleanaircrew.org/faq/why-can-you-smell-a-fart-in-an-n95-respirator-mask/) - https://www.dailymail.co.uk/sciencetech/article-8275855/Professor-answers-question-jeans-stop-fart-mask-prevent-coronavirus.html https://lifehacker.com/why-you-can-smell-a-fart-through-a-mask-1844470030 https://sea.mashable.com/science/11653/face-masks-help-protect-against-covid-19-but-heres-why-it-doesnt-shield-you-from-stinky-farts - [Is asymptomatic transmission rare or common?](https://cleanaircrew.org/faq/is-asymptomatic-transmission-rare-or-common/) - 59% of all SARS-CoV-2 infections result from asymptomatic transmission. Asymptomatic COVID transmission is quite common. - [Can COVID cause erectile dysfunction?](https://cleanaircrew.org/faq/can-covid-cause-erectile-dysfunction/) - "One study found that people infected with the virus were more than 5 times more likely to develop ED. In another small study, researchers took penis tissue samples from two men who’d been infected with COVID-19. One had had severe symptoms, the other mild. The samples were taken before both men had surgery for severe - [How can increased ventilation rates increase school district income?](https://cleanaircrew.org/faq/how-can-increased-ventilation-rates-increase-school-district-income/) - "Overall, the available research indicates that increased ventilation rates in classrooms are associated with reduced student absence. For elementary and middle school students, reduced student absence has been shown to be associated with higher grade point averages and higher scores in academic achievement tests." "In offices, even very small decreases in absence rates from increases - [UK DIY Air Filters - (CR box)](https://cleanaircrew.org/faq/uk-diy-corsirosenthal-box-cr-box/) - Materials available to build a DIY air filter (also known as a CorsiRosenthal box, or CRbox) can vary by location. We feature two designs here. UK Round Vent Axia 14" box fan Vent Axia 14 inch fan, 4 x 3M Filtrete MPR1900 – 20 x 25 x 1 inches This build from @PeteUK7 details the - [How to build a DIY air filter with a box fan, tape, and MERV13 filters - CorsiRosenthal Box](https://cleanaircrew.org/faq/how-to-build-a-diy-air-filter-with-a-box-fan-tape-and-merv13-filters-corsirosenthal-box/) - Printable diagram QuickStart Diagram - How to build a DIY air purifier Parts List 20 inch (standard size) Box fan 20x20x1 or 20x20x2 MERV 13 furnace filters (1, 2, 4 or 5 filter designs available) Duct tape or packing tape Instructional Videos This Old House assembles a 4 filter air cleaner, using 20x20x2 MERV13 filters ## FAQs - [The Record Player Build](https://cleanaircrew.org/ufaq/the-record-player-build-2/) - This build by Amanda H, has a printed out record label in the middle. This build is simply amazing! Click through to see it in action!!! She was kind enough to provide the files so that you could recreate this build as well. Thank you, Amanda!!! File is located: Click here to go back to - [We can only open our windows, but not if the children have to wear a coat? Natural Ventilation...](https://cleanaircrew.org/ufaq/we-can-only-open-our-windows-but-not-if-the-children-have-to-wear-a-coat-natural-ventilation-2/) - Quick Tip if your windows and doors open - at the VERY LEAST, open during breaks and lunches. Source: Professor Cathy Noakes: "If its cold, crack the windows rather than opening them fully and then open them wider to air the room periodically say at break times. The colder it is, the smaller the gap - [4 Filter Build - A Corsi/Rosenthal Box also called the Compretto Cube. Top is a fan, but the bottom is just cardboard - no bottom filter.](https://cleanaircrew.org/ufaq/4-filter-build-a-corsi-rosenthal-box-also-called-the-compretto-cube-top-is-a-fan-but-the-bottom-is-just-cardboard-no-bottom-filter-2/) - Click here to go back to all FAQ's. There are several different builds below. No matter which one you choose make sure you put a shroud on the front of the fan to enhance efficiency. Here is a 4 filter build known as the Compretto Cube: hosted by Philip Neustrom. This diagram is just a - [France - no parts sourced there yet.](https://cleanaircrew.org/ufaq/france-any-way-of-sourcing-parts-there/) - Click here to go back to all FAQ's. Click here to go back to all FAQ's. - [Switzerland Build](https://cleanaircrew.org/ufaq/switzerland-builds/) - Click here to go back to all FAQ's. Corsi-Rosenthal Style Air Cleaner with 5 Camfil F7 Filters, Swiss Made 🇨🇭 /cc @DavidElfstrom @JimRosenthal4 @CorsIAQ pic.twitter.com/oQigkrjXb5— Markus Leutwyler 🇨🇭 (@twtomcat) September 2, 2021 Click here to go back to all FAQ's. - [Hall of Fame of Corsi/Rosenthal Boxes - or ideas for your own box!](https://cleanaircrew.org/ufaq/gallery-of-corsi-rosenthal-boxes-built-by-regular-people/) - Click here to go back to all FAQ's. These are pictures of each tweet of someone who has built a CR Box, and all are linked to the actual tweet. This is by design so that you can click on the tweet, and ask any questions you might have directly of them. Such as, "What - [How to keep little fingers out of the filters? Or - can students touch the filters?](https://cleanaircrew.org/ufaq/how-to-keep-little-fingers-out-of-the-filters/) - It is recommended not to - the virus might be on the filters - but It is far more likely that airborne transmission will occur. The odds of transfer from the filters to the hands and then to the mucosal regions of eyes, mouth, or nose are very, very low. The filter is actually a - [Electricity - are these fans a danger with the filters attached?](https://cleanaircrew.org/ufaq/with-the-filters-attached-will-it-burn-up-the-fan-motor/) - Click here to go back to all FAQ's. No: Measured by Underwriter's Laboratories, Inc. Smart Air has been doing the same thing since 2013 - only 5 had issues, most likely issues with the fan motor itself, not the load. There were no actual fires. - [Do we need to wear masks even though we have a couple of air cleaners?](https://cleanaircrew.org/ufaq/do-we-need-to-wear-masks-even-though-we-have-a-couple-of-air-cleaners/) - I'm sorry, you do still need to wear a mask. Why? For the same reasons Health Care Workers continue to get infected in hospitals which have excellent ventilation with 6 Air Changes Per Hour. Ventilation cleans up far-field aerosols (>6 feet away), but cannot clean the air of aerosols that have just been emitted by - [Wouldn't it work better if we added UVC bulbs under the shroud like hospitals do?](https://cleanaircrew.org/ufaq/wouldnt-it-work-better-if-we-added-uvc-bulbs-under-the-shroud-like-hospitals-do/) - This is a great question! Two part answer. First part is that it's actually two different technologies. Bulbs are usually used to clean items in a sealed container in a hospital. Hospitals use UVGI to clean the air. And it can be extremely effective. Here's respiratory virus transmission expert, Dr. Don Milton (MD, PhD) ..." - [How do I dispose of the filters?](https://cleanaircrew.org/ufaq/how-do-i-dispose-of-the-filters/) - Put on your N100 elastomeric respirator (more comfortable than N95). Does not have to be N100 - just better masks work...better. Carefully, pick up the Corsi/Rosenthal box and gently take it outside. Carefully cut the filters apart, gently peel it back to get the fan off. Separate the filters and gently place in a garbage - [How loud are these?](https://cleanaircrew.org/ufaq/how-loud-are-these/) - Roughly 51 DBA..This is more quiet than a refrigerator. - [How expensive is the Corsi/Rosenthal Box?](https://cleanaircrew.org/ufaq/how-expensive-is-the-corsi-rosenthal-box/) - You can build one of these for just under $100, and it will help significantly remove respiratory aerosols that contain SARS-COV-2 from the air. We recommend at least 2 of them in a normal sized classroom. $200. Keep in mind - something is better than nothing. Even if you did the single filter build, which - [How long do the filters last?](https://cleanaircrew.org/ufaq/how-long-do-the-filters-last/) - Always refer to the manufacturer's specifications. But a general rule of thumb is: If used during smoke season, 3 months. If during regular usage, 6 month. Additional details on MERV 13-A filters which for sure will are the ones that last that long. - [Electricity - how much does it use?](https://cleanaircrew.org/ufaq/electricity-how-much-does-it-use/) - This is with the Utilitech 20" Box fan - 58 Watts when cranked to max, as measured by Jim Rosenthal. The measurements below are for: No filter attached. 1 filter attached - 1", 2", 4" Box filter - the full Corsi/Rosenthal Box attached. This with the Lasko 20" Box Fan - 89 Watts when cranked - [Should I add 2 filters on top of each other? (No)](https://cleanaircrew.org/ufaq/should-i-add-2-filters-on-top-of-each-other-no/) - As discussed here, it decreases performance. The 1" filters are fine - although you would get even better performance with 2" filters. Just not 1" filters doubled up. - [Why should it be pointed up at the ceiling?  I saw a study that said pointed down is better.](https://cleanaircrew.org/ufaq/why-should-it-be-pointed-up-at-the-ceiling-i-saw-a-study-that-said-pointed-down-is-better-2/) - That study did not include the risk of reaersolization (blow back up in the air) of dried respiratory aerosols that will have settled on the ground. You will give a little in efficiency to gain safety. http://poppendieck.com/IAQ/COVID19%20FAQ.html - [Where should it/they be placed in the room?](https://cleanaircrew.org/ufaq/where-should-it-they-be-placed-in-the-room/) - A simple question, but can be a complicated answer. Try not to place next to a wall if possible. You want air flow. If you know who's infected, next to them (typically placement in a patient's hospital room). If you are in a classroom, you will want 2. Place one in the center of the - [oldWe can only open our windows, but not if the children have to wear a coat? Natural Ventilation...](https://cleanaircrew.org/ufaq/we-can-only-open-our-windows-but-not-if-the-children-have-to-wear-a-coat-natural-ventilation/) - Click here to go back to all FAQ's. Quick Tip if your windows and doors open - at the VERY LEAST, open during breaks and lunches. Source: Professor Cathy Noakes: "If its cold, crack the windows rather than opening them fully and then open them wider to air the room periodically say at break times. - [I need some sort of letter and tactics to overcome objections.](https://cleanaircrew.org/ufaq/i-need-some-sort-of-letter-to-overcome-objections/) - Here's such a letter. It addresses Air cleaner efficacy in general, and the Corsi/Rosenthal Box, in specific. HVAC infrastructure concerns (it will not cause issues). Electrical concerns (will not cause fires). How to use such a letter? Possible ideas: Just emailing it to the concerned individual. Better would be to find parents "...who have working - [HVAC - someone said it will mess up the HVAC of our building?](https://cleanaircrew.org/ufaq/hvac-someone-said-it-will-mess-up-the-hvac-of-our-building/) - 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, - [Regarding putting these in classroom - I thought kids don't transmit CoVid?](https://cleanaircrew.org/ufaq/regarding-putting-these-in-classroom-i-thought-kids-dont-transmit-covid/) - They get it and transmit it. They have ACE2 receptors, which SARS-COV-2 targets. And just like adults, they have a thermal plume wafting SARS-COV-2 up to you. Basically, our body's own heat forms a never-ending plume of air movement upwards because heat rises. "While there has been no systematic study on human thermal plume in - [Won't a portable air filter (cleaner) just move the air with contaminated aerosols around to infect more people?](https://cleanaircrew.org/ufaq/wont-a-portable-air-filter-cleaner-just-move-the-air-with-contaminated-aerosols-around-to-infect-more-people/) - Per Dr. Poppendieck "I actually love this question because it shows the person has thought about what we intuitively understand about our indoor environment. We generally don't feel the air move indoors. Humans can sense air movement down to about 0.1 m/s (0.3 ft/s). Below that, we generally consider the air to be "still." Hence, - [Does the Corsi/Rosenthal Box work?](https://cleanaircrew.org/ufaq/does-the-corsi-rosenthal-box-work/) - Click here to go back to all FAQ's. Yes - it removes aerosols from the air. How well does it work? Very well. Dr. Marwa Zaatari, Chief Science Officer at Blue Box Air & ASHRAE Associate Member "It is the most cost effective purifier on the chart." - this evaluation is from Dr. Zaatari, who - [How do I know air cleaners even work?](https://cleanaircrew.org/ufaq/how-do-i-know-air-cleaners-even-work/) - Because they have been studied, and found to be very effective at removing aerosols from the air: Classrooms: "...our study shows that box fan air cleaners can serve as an effective low-cost alternative for mitigating airborne transmission risks in poorly ventilated spaces." Hospitals (preprint): "A single bed hospital room equipped with an excellent ventilation rate (∼ - [But my lungs are tough!   (A quick discussion of how much work your lus do )](https://cleanaircrew.org/ufaq/but-my-lungs-are-tough-a-quick-discussion-of-how-much-work-your-lungs-do/) - Click here to go back to all FAQ's. Sure, they are. They have to be to enable you to breathe. But - if you catch CoVid, you literally drown in the mucus created in your lungs. Speaking of drowning - your lungs process over 2,000 gallons of air, per day. That’s a swimming pool of - [Why use an air cleaner? The air doesn't look dirty, and I can breathe easily?!](https://cleanaircrew.org/ufaq/why-use-an-air-cleaner-the-air-doesnt-look-dirty-and-i-can-breathe-easily/) - Click here to go back to all FAQ's. SARS-COV-2, the virus that causes CoVid, is actually carried by respiratory aerosols. Portable air cleaners (also called air purifiers and air filters), work by pulling air through high-quality filters. As the air cleaner pulls air in with the fan contained in it, the filters attached to it - [Where can I find the original Build instructions in the Mega Corsi/Rosenthal thread?](https://cleanaircrew.org/ufaq/where-can-i-find-the-original-build-instructions-in-the-mega-corsi-rosenthal-thread/) - sdf sdf - [Type of Filters](https://cleanaircrew.org/ufaq/type-of-filters/) - 20"x20"x1" or 20"x20"x2" MERV 13 filters are recommended. MERV 13-A filters are available here. Why 13-A? Because they are top of the line. If MERV 13-A filters are not available, the next filters recommended are MERV 13 filters from 3M . Specifically, 3M 1900 filters are excellent (the people on the thread are IAQ experts) . - [Type of Tape](https://cleanaircrew.org/ufaq/type-of-tape-2/) - Any type of duct tape is recommended. Keep in mind that you can use the duct tape color to accessorize your DIY Air Cleaner. Please see the Gallery for lots of creative fun ideas. - [Type of Fan](https://cleanaircrew.org/ufaq/type-of-fan/) - The Corsi/Rosenthal Box is based on a 20" x 20" box fan. This is because the size perfectly matches with 20"x20" filters. Some countries have no box fans. Round fans have been used to build the Corsi/Rosenthal Box. 20" Box Fan - very important that the On button/ Speed Control is on the outer edges - [How to build the shroud](https://cleanaircrew.org/ufaq/how-to-build-the-shroud-2/) - Next, we are going to make a fan shroud..a fancy way of saying we are going to block off the square corners, so just the round fan is exposed. This was discussed here by Jim Rosenthal. Short version - the round fan does not reach the square corners, so there's a gap there, and is - [I just want to buy an air cleaner.](https://cleanaircrew.org/ufaq/i-just-want-to-buy-an-air-cleaner-2/) - Please see our air cleaner/filter buying guide. Also these tweets are two excellent sources - both from Indoor Air Quality Experts. This is Dr. Shelly Miller - who authored this tweet - and co-authored the tools she mentions here. This is Marwa Zaatari, who regularly helps decipher the complex air cleaner market to get you - [oldCómo construir unos filtros de aire de bajo costo? Recursos aquí!](https://cleanaircrew.org/ufaq/como-construir-unos-filtros-de-aire-de-bajo-costo-recursos-aqui/) - Translations by Emily Barnes Franklin - thank you! Click here to go back to all FAQ’s. Click here to go back to all FAQ’s. - [Round Fan Build - for countries with no box fans.](https://cleanaircrew.org/ufaq/round-fan-build-for-countries-with-no-box-fans-2/) - Some countries don't have box fans, but have round fans. "Presenting V1.0 accessible, effective and validated DIY filters using round fans inspired by the #CorsiRosenthalBox. They are the result of international collaboration from designers, engineers and advocates in @TheWHN Airborne Group DIY Filter Team.". Source here. For the type of fan, "For gym fans, anything - [1 Filter Build - aka single filter strapped to the back of a box fan.](https://cleanaircrew.org/ufaq/1-filter-build-aka-single-filter-strapped-to-the-back-of-a-box-fan-2/) - The single filter version did very well vs commercial air cleaners. Here's what the final build can look like with judicious use of duct tape. Pretty, pretty sharp: Here are the actual measurements: Actual Build Here's the actual build from the above Twitter thread. Here's a more simple, slightly less effective single filter build by - [2 Filter Build - The Wedge/ The Triangle - top and bottom are cardboard.](https://cleanaircrew.org/ufaq/2-filter-build-the-wedge-the-triangle-top-and-bottom-are-cardboard/) - Click here to go back to all FAQ's. Here's one as a goal - it's the same triangle filter as in the video, but with a shroud added for optimum performance, and adhesive contact liner layered over the cardboard. Beautifully done! This was what it looked like before the contact paper was added. In this - [5 Filter Build - The Original Corsi/Rosethal Box where the top is a fan, and bottom is a filter.](https://cleanaircrew.org/ufaq/5-filter-build-the-original-corsi-rosethal-box-where-the-top-is-a-fan-and-bottom-is-a-filter-2/) - End goal: Shopping List - the below links may quickly no longer be valid, so including a description of each item. No affiliation with any company whose products I have listed: 20" Box Fan. Tape. Filters. Build time! Tape the boxes together- very important to point the arrows on the edges of the filters, inwards. - [Read Me First](https://cleanaircrew.org/ufaq/read-me-first-2/) - Essential Click here to go back to all FAQ's. Before reading any farther, even with 2 or 3 portable air cleaners in your space, everyone must wear a mask (more on masks, kids' masks and reusable elastomeric respirators). Like getting closer to a cigarette smoker, respiratory aerosols get thicker in concentration as you get closer - [How long does it take to flush/wash out a room after being occupied?](https://cleanaircrew.org/ufaq/how-long-does-it-take-to-flush-wash-out-a-room-after-being-occupied/) - Click here to go back to all FAQ's. Simple question, complicated answer. First one - assuming you have an air cleaner - the time it takes to do 3 air changes. Source: Click here to go back to all FAQ's. - [Science Project - do you have any ideas?](https://cleanaircrew.org/ufaq/science-project-do-you-have-any-ideas/) - Click here to go back to all FAQ's. Maybe :) . This is page is really just a collection of ideas to help inspire YOU. It was conceived as a combination of physics (aerosols), biology (lungs), and math (large number conversions). All parts are meant to be used separately or together. For now, just going - [How was the optimum shroud developed by David Elfstrom?](https://cleanaircrew.org/ufaq/how-was-the-optimum-shroud-developed-by-david-elfstrom/) - Click here to go back to all FAQ's. Laborious Experimentation - drop him a "like" on Twitter! Scroll up on this thread to see his excellent work! And this optimization thread (scroll up): Click here to go back to all FAQ's. - [oldWhy should it be pointed up at the ceiling?  I saw a study that said pointed down is better.](https://cleanaircrew.org/ufaq/why-should-it-be-pointed-up-at-the-ceiling-i-saw-a-study-that-said-pointed-down-is-better/) - Click here to go back to all FAQ's. That study did not include the risk of reaersolization (blow back up in the air) of dried respiratory aerosols that will have settled on the ground. You will give a little in efficiency to gain safety. http://poppendieck.com/IAQ/COVID19%20FAQ.html Click here to go back to all FAQ's. - [Cómo construir unos filtros de aire de bajo costo? Recursos aquí!](https://cleanaircrew.org/ufaq/como-construir-unos-filtros-de-aire-de-bajo-costo-recursos-aqui-2/) - Translations by Emily Barnes Franklin - thank you! Click here to go back to all FAQ’s. Click here to go back to all FAQ’s. - [I can't bring in an air cleaner, but can bring in a fan - got any ideas?](https://cleanaircrew.org/ufaq/i-cant-bring-in-an-air-cleaner-but-can-bring-in-a-fan-got-any-ideas-2/) - "Lasko FF305 Air Flex 2-in-1 20-inch Box Fan and Air Purifier in One with MERV10 Air Purifying Filter" Won't be as good - but something is better than nothing! The filters here are 13-A - so I would buy one and swap out the MERV 10 that it comes with. No affiliation, just these are - [oldI just want to buy an air cleaner.](https://cleanaircrew.org/ufaq/i-just-want-to-buy-an-air-cleaner/) - Click here to go back to all FAQ's. Please see our air cleaner/filter buying guide. Also these tweets are two excellent sources - both from Indoor Air Quality Experts. This is Dr. Shelly Miller - who authored this tweet - and co-authored the tools she mentions here. This is Marwa Zaatari, who regularly helps decipher - [oldRound Fan Build - for countries with no box fans.](https://cleanaircrew.org/ufaq/round-fan-build-for-countries-with-no-box-fans/) - Click here to go back to all FAQ's. Some countries don't have box fans, but have round fans. "Presenting V1.0 accessible, effective and validated DIY filters using round fans inspired by the #CorsiRosenthalBox. They are the result of international collaboration from designers, engineers and advocates in @TheWHN Airborne Group DIY Filter Team.". Source here. For - [old5 Filter Build - The Original Corsi/Rosethal Box where the top is a fan, and bottom is a filter.](https://cleanaircrew.org/ufaq/5-filter-build-the-original-corsi-rosethal-box-where-the-top-is-a-fan-and-bottom-is-a-filter/) - Click here to go back to all FAQ's. End goal: Shopping List - the below links may quickly no longer be valid, so including a description of each item. No affiliation with any company whose products I have listed: 20" Box Fan. Tape. Filters. Build time! Tape the boxes together- very important to point the - [old4 Filter Build - A Corsi/Rosenthal Box also called the Compretto Cube. Top is a fan, but the bottom is just cardboard - no bottom filter.](https://cleanaircrew.org/ufaq/4-filter-build-a-corsi-rosenthal-box-also-called-the-compretto-cube-top-is-a-fan-but-the-bottom-is-just-cardboard-no-bottom-filter/) - Click here to go back to all FAQ's. There are several different builds below. No matter which one you choose make sure you put a shroud on the front of the fan to enhance efficiency. Here is a 4 filter build known as the Compretto Cube: hosted by Philip Neustrom. This diagram is just a - [old2 Filter Build - Forms a Triangle - top and bottom are cardboard.](https://cleanaircrew.org/ufaq/2-filter-build-forms-a-triangle-top-and-bottom-are-cardboard/) - Click here to go back to all FAQ's. Here's one as a goal - it's the same triangle filter as in the video, but with a shroud added for optimum performance, and adhesive contact liner layered over the cardboard. Beautifully done! This was what it looked like before the contact paper was added. In this - [old1 Filter Build - aka single filter strapped to the back of a box fan.](https://cleanaircrew.org/ufaq/1-filter-build-aka-single-filter-strapped-to-the-back-of-a-box-fan/) - Click here to go back to all FAQ's. The single filter version did very well vs commercial air cleaners. Here's what the final build can look like with judicious use of duct tape. Pretty, pretty sharp: Here are the actual measurements: Actual Build Here's the actual build from the above Twitter thread. Here's a more - [oldI can't bring in an air cleaner, but can bring in a fan - got any ideas?](https://cleanaircrew.org/ufaq/i-cant-bring-in-an-air-cleaner-but-can-bring-in-a-fan-got-any-ideas/) - Click here to go back to all FAQ's. "Lasko FF305 Air Flex 2-in-1 20-inch Box Fan and Air Purifier in One with MERV10 Air Purifying Filter" Won't be as good - but something is better than nothing! The filters here are 13-A - so I would buy one and swap out the MERV 10 that - [oldType of Fan](https://cleanaircrew.org/ufaq/what-type-of-fan-should-i-use/) - Click here to go back to all FAQ's. The Corsi/Rosenthal Box is based on a 20" x 20" box fan. This is because the size perfectly matches with 20"x20" filters. Some countries have no box fans. Round fans have been used to build the Corsi/Rosenthal Box. 20" Box Fan - very important that the On - [oldHow to build the shroud](https://cleanaircrew.org/ufaq/how-to-build-the-shroud/) - Click here to go back to all FAQ's. Next, we are going to make a fan shroud..a fancy way of saying we are going to block off the square corners, so just the round fan is exposed. This was discussed here by Jim Rosenthal. Short version - the round fan does not reach the square - [oldType of Tape](https://cleanaircrew.org/ufaq/type-of-tape/) - Click here to go back to all FAQ's. Any type of duct tape is recommended. Keep in mind that you can use the duct tape color to accessorize your DIY Air Cleaner. Please see the Gallery for lots of creative fun ideas. Click here to go back to all FAQ's. - [oldType of Filters](https://cleanaircrew.org/ufaq/buy-filters/) - Click here to go back to all FAQ's. 20"x20"x1" or 20"x20"x2" MERV 13 filters are recommended. MERV 13-A filters are available here. Why 13-A? Because they are top of the line. If MERV 13-A filters are not available, the next filters recommended are MERV 13 filters from 3M . Specifically, 3M 1900 filters are excellent (the - [oldThe Record Player Build](https://cleanaircrew.org/ufaq/the-record-player-build/) - This build by Amanda H, has a printed out record label in the middle. This build is simply amazing! Click through to see it in action!!! She was kind enough to provide the files so that you could recreate this build as well. Thank you, Amanda!!! File is located: Click here to go back to - [oldRead Me First](https://cleanaircrew.org/ufaq/read-me-first/) - Essential Click here to go back to all FAQ's. Before reading any farther, even with 2 or 3 portable air cleaners in your space, everyone must wear a mask (more on masks, kids' masks and reusable elastomeric respirators). Like getting closer to a cigarette smoker, respiratory aerosols get thicker in concentration as you get closer - [How does the box stack up against the NYC filters installed in school?](https://cleanaircrew.org/ufaq/how-does-the-box-stack-up-against-the-nyc-filters-installed-in-school/) - Click here to go back to all FAQ's. Better. NYC’s CADR for smoke was 129. The Corsi/Rosenthal Box CADR was 132. And that was with MERV 10/11 filters. The Corsi/Rosenthal Box should be made with MERV 13 filters, so will test even higher. These measurements are in process. ## Galleries - [BoxFanFilters](https://cleanaircrew.org/?post_type=envira&p=1277) ## Categories - [Uncategorized](https://cleanaircrew.org/category/uncategorized/) - [Guides](https://cleanaircrew.org/category/guides/) - [Resources](https://cleanaircrew.org/category/resources/) - [Images](https://cleanaircrew.org/category/images/) - [print](https://cleanaircrew.org/category/images/print/) - [Filtration](https://cleanaircrew.org/category/filtration/) - [DIY](https://cleanaircrew.org/category/guides/diy/) - [Ventilation](https://cleanaircrew.org/category/ventilation/) - [CO2 monitors](https://cleanaircrew.org/category/co2/) - [Masks](https://cleanaircrew.org/category/masks/) - [Schools](https://cleanaircrew.org/category/schools/) - [Elastomeric Respirators](https://cleanaircrew.org/category/masks/elastomericrespirators/) - [KidsMasks](https://cleanaircrew.org/category/masks/kidsmasks/) - [Featured](https://cleanaircrew.org/category/featured/) - Pinned articles - [Articles](https://cleanaircrew.org/category/resources/articles/) - [crbox](https://cleanaircrew.org/category/filtration/crbox/) - DIY air filter also known as the Corsi-Rosenthal box or CRbox. MERV 13 filters and a fan! - [Posts](https://cleanaircrew.org/category/resources/posts/) - Clean Air Crew posts ## Tags - [masks](https://cleanaircrew.org/tag/masks/) - [filtration](https://cleanaircrew.org/tag/filtration/) - [filter](https://cleanaircrew.org/tag/filter/) - [air cleaner](https://cleanaircrew.org/tag/air-cleaner/) - [HEPA](https://cleanaircrew.org/tag/hepa/) - [MERV13](https://cleanaircrew.org/tag/merv13/) - [buying guide](https://cleanaircrew.org/tag/buying-guide/) - [diy](https://cleanaircrew.org/tag/diy/) - [co2](https://cleanaircrew.org/tag/co2/) - [aranet](https://cleanaircrew.org/tag/aranet/) - [coupon](https://cleanaircrew.org/tag/coupon/) - [ventilation](https://cleanaircrew.org/tag/ventilation/) - [tools](https://cleanaircrew.org/tag/tools/) - [aerosols](https://cleanaircrew.org/tag/aerosols/) - [links](https://cleanaircrew.org/tag/links/) - [school](https://cleanaircrew.org/tag/school/) - [reviews](https://cleanaircrew.org/tag/reviews/) - [kidsmasks](https://cleanaircrew.org/tag/kidsmasks/) - [elastomericrespirators](https://cleanaircrew.org/tag/elastomericrespirators/) - [schools](https://cleanaircrew.org/tag/schools/) - [behavior](https://cleanaircrew.org/tag/behavior/) - [homeschool](https://cleanaircrew.org/tag/homeschool/) - [outside](https://cleanaircrew.org/tag/outside/) - [n95](https://cleanaircrew.org/tag/n95/) - [airborne](https://cleanaircrew.org/tag/airborne/) - [medical](https://cleanaircrew.org/tag/medical/) - [crbox](https://cleanaircrew.org/tag/crbox/) - [smoke](https://cleanaircrew.org/tag/smoke/) - [wildfire](https://cleanaircrew.org/tag/wildfire/) ## Categories - [COVID effects](https://cleanaircrew.org/faq/category/covid-effects/) - COVID effects - [COVID transmission](https://cleanaircrew.org/faq/category/covid-transmission/) - COVID transmission - [Masks](https://cleanaircrew.org/faq/category/masks/) - masks - [Air filters](https://cleanaircrew.org/faq/category/air-filters/) - air filters - [DIY air filters - CorsiRosenthal Box (CRBox)](https://cleanaircrew.org/faq/category/crbox/) - [Ventilation](https://cleanaircrew.org/faq/category/ventilation/) - Ventilation, bringing fresh outdoor air indoors - [CO2 monitoring](https://cleanaircrew.org/faq/category/ventilation/co2/) - carbon dioxide monitoring - [Health effects](https://cleanaircrew.org/faq/category/covid-effects/health/) - COVID health effects - [Societal effects](https://cleanaircrew.org/faq/category/covid-effects/society/) - effects on society - [Resources / Links](https://cleanaircrew.org/faq/category/resources/) - Links to useful resources and organizations with related goals - [Bird Flu H5N1](https://cleanaircrew.org/faq/category/bird-flu/) - bird flu H5N1 avian flu ## FAQ Categories - [Corsi/Rosenthal Box](https://cleanaircrew.org/ufaq-category/corsirosenthalbox/) - [Build](https://cleanaircrew.org/ufaq-category/build/) - How to build - [Does_It_Work](https://cleanaircrew.org/ufaq-category/doesitwork/) - [ImplementationDetails](https://cleanaircrew.org/ufaq-category/implementationdetails/) - [CountrySpecific](https://cleanaircrew.org/ufaq-category/countryspecific/) - For example – France currently is not known to have a good option. - [parts](https://cleanaircrew.org/ufaq-category/parts/) - Details on what parts to buy – fan, filters, tape. - [shroud](https://cleanaircrew.org/ufaq-category/shroud/) - All questions about the shroud. - [Examples](https://cleanaircrew.org/ufaq-category/examples/) - [Why](https://cleanaircrew.org/ufaq-category/why/) - [Safety](https://cleanaircrew.org/ufaq-category/safety/) - [Fans](https://cleanaircrew.org/ufaq-category/fans/) - [Natural_Ventilation](https://cleanaircrew.org/ufaq-category/natural_ventilation/) - [General](https://cleanaircrew.org/ufaq-category/general/) - [build2](https://cleanaircrew.org/ufaq-category/build2/) - second build after “build” choked. Weird. - [testedBuild](https://cleanaircrew.org/ufaq-category/testedbuild/) - [build3](https://cleanaircrew.org/ufaq-category/build3/) - [done](https://cleanaircrew.org/ufaq-category/done/) - [added to new faq](https://cleanaircrew.org/ufaq-category/added-to-new-faq/) ## FAQ Tags - [CR Box](https://cleanaircrew.org/ufaq-tag/cr-box/) - [Corsi/Rosenthal](https://cleanaircrew.org/ufaq-tag/corsi-rosenthal/) - [place](https://cleanaircrew.org/ufaq-tag/place/) - [placement](https://cleanaircrew.org/ufaq-tag/placement/) - [middle of room](https://cleanaircrew.org/ufaq-tag/middle-of-room/) - [center of room](https://cleanaircrew.org/ufaq-tag/center-of-room/) - [near window](https://cleanaircrew.org/ufaq-tag/near-window/) - [DIY air filter](https://cleanaircrew.org/ufaq-tag/diy-air-filter/) - [5 filters](https://cleanaircrew.org/ufaq-tag/5-filters/) - [bottom](https://cleanaircrew.org/ufaq-tag/bottom/) - [bottom filter](https://cleanaircrew.org/ufaq-tag/bottom-filter/) - [4 filter](https://cleanaircrew.org/ufaq-tag/4-filter/) - [2 filters](https://cleanaircrew.org/ufaq-tag/2-filters/) - [build](https://cleanaircrew.org/ufaq-tag/build/) - [round fan](https://cleanaircrew.org/ufaq-tag/round-fan/) - [cost](https://cleanaircrew.org/ufaq-tag/cost/) - [expense](https://cleanaircrew.org/ufaq-tag/expense/) - [expensive](https://cleanaircrew.org/ufaq-tag/expensive/) - [cheap](https://cleanaircrew.org/ufaq-tag/cheap/) - [filters](https://cleanaircrew.org/ufaq-tag/filters/) - [masks](https://cleanaircrew.org/ufaq-tag/masks/) - [dispose](https://cleanaircrew.org/ufaq-tag/dispose/) - [disposal](https://cleanaircrew.org/ufaq-tag/disposal/) - [filter](https://cleanaircrew.org/ufaq-tag/filter/) - [why](https://cleanaircrew.org/ufaq-tag/why/) - [blow in face](https://cleanaircrew.org/ufaq-tag/blow-in-face/) - [just move around](https://cleanaircrew.org/ufaq-tag/just-move-around/) - [efficiency](https://cleanaircrew.org/ufaq-tag/efficiency/) - [safeety](https://cleanaircrew.org/ufaq-tag/safeety/) - [Safety](https://cleanaircrew.org/ufaq-tag/safety/) - [HVAC](https://cleanaircrew.org/ufaq-tag/hvac/) - [kids](https://cleanaircrew.org/ufaq-tag/kids/) - [children](https://cleanaircrew.org/ufaq-tag/children/) - [classrooms](https://cleanaircrew.org/ufaq-tag/classrooms/) - [shroud](https://cleanaircrew.org/ufaq-tag/shroud/) - [gallery](https://cleanaircrew.org/ufaq-tag/gallery/) - [regular people](https://cleanaircrew.org/ufaq-tag/regular-people/) - [efficience](https://cleanaircrew.org/ufaq-tag/efficience/) - [tape](https://cleanaircrew.org/ufaq-tag/tape/) - [duct](https://cleanaircrew.org/ufaq-tag/duct/) - [duct tape](https://cleanaircrew.org/ufaq-tag/duct-tape/) - [painters tape](https://cleanaircrew.org/ufaq-tag/painters-tape/)