Many thanks for the support. Many students will benefit from your generosity!

Easy, inexpensive ( at largely under $100) and certified effective by 3M, others, for the last five years. CR boxes used in schools and universities across the country and around the world, thanks to co-inventors @corsiaq.bsky.social and @jimrosenthal5.bsky.social youtu.be/hIuH-2naozI?...

Really excellent work! This test should be required for all air cleaners that produce chemical byproducts! (CR Boxes do not,)

Glad it helped you and the cats!

Check out the USEPA's newest air cleaning allies activity book for children. DJ is definitely the coolest (and with additional filters in parallel - a more effective ally than Aerie).👇 www.epa.gov/system/files...

This is great. An EPA activity book for elementary school kids on air cleaning: www.epa.gov/system/files...

Excellent study showing how bringing in filtered outside air improves asthma outcomes. This is important information and needs to be part of every residential HVAC installation. Build tight - but with filtered ventlation1 doi.org/10.1016/j.bu...

Another great week of helping folks access cleaner indoor air. Be sure to follow us and RT. We've got A LOT of new resources to share in preparation for back-to-school season. @corsiaq.bsky.social @polsiewski.bsky.social @jimrosenthal5.bsky.social @jaydocovid.bsky.social @jehnml.bsky.social

My Father’s Day card from my wife. I was one of the original “Weber Demo Guys.” A few years ago my wife asked me to retire my Weber grill (too much smoke). So not only am I not a “King” - I don’t have a grill. (Sounds familiar.)

Wildfire smoke is covering large areas of the US. Time to make a Corsi-Rosenthal Box. They work! www.spokesman.com/stories/2025...

Very interesting article on the University of Utah program to monitor and modify indoor air for better IAQ. This data can drive decisions on filters, equipment and operations. It is the wave of the future. Every large institution should be heading in this direction. attheu.utah.edu/research/doe...

We are entering “wildfire season” in North America. This is an excellent site showing where the wildfires are located and where the wildfire smoke is headed. Be prepared! Firesmoke.ca

The BC Wildfire Research group did tests to develop a "clean air shelter" for firefighters. One test used a 14'X24' Ranger tent. They attached a MERV 13 CR box onto the tent - facing in. The positive pressure from the fan and the CR Box filters reduced PM 2.5 by 91%! Ingenuity triumphs again!

I have tested MERV 13 washable filters. All have been very resistant to air flow. I would not recommend using them in CR boxes.

Excellent article on the effectiveness of Corsi-Rosenthal Boxes on wildfire smoke and other PM2.5 airborne contaminants: www.washingtonpost.com/climate-solu...

Outstanding video on the success of Red Rock Elementary in building Corsi-Rosenthal Boxes. Many thanks to this great teacher and her students. Others can do the same. Just apply for a grant!

Contrary to what many believe, disasters can bring out the best in people. This is an incredible thread on how people can work together to accomplish positive things in the worst of times.

Am getting inquiries on how to stay safe in terms of air LA due to fires...indoor filtration is key. Inexpensive CR boxes can be built in less than 1 hour by a 5 year old and outperform more expensive HEPAs. KN95 for particles. Respirators with activated carbon is concerned about gases/fumes. (1/2)

TY @jimrosenthal5.bsky.social LA County Public Health, LA County Board of Supervisors, the City of Los Angeles and every city in the region should also be distributing free N95s AND air cleaners/CR boxes, along with basic information on how to minimize the health harms from wildifire pollution.

🧵Rapid Response: Air Filters for LA We are providing fans and filters to help LA residents breathe cleaner air during these devastating fires. Follow this thread for updates and how to get involved. Donate to support: paypal.com/donate?campa...

If you live in an area currently experiencing high levels of wildfire smoke, make sure you are using effective filters. If you are using mechanical MERV 8 filters, change them to MERV 13. This article explains why: www.texairfilters.com/using-a-cors...

The purpose of this post is two-fold. 1. There is a crisis with wildfire smoke in LA. We will do everything we can to be supportive. But the logistics are a nightmare. 2. If you live in an area where wildfire smoke is a concern, now is the time to obtain the supplies to create a "safe air center."

Yes. It is super easy to build. But, best of all, it works!

The horrific fires in the LA area are creating massive amounts of wildfire smoke and a reminder that communities need to be providing "safe air centers". Grants for free filters and fans to build Corsi-Rosenthal boxes are available at www.corsirosenthalfoundation.org

The 2024 Corsi-Rosenthal Box Awards are finally here. Congratulations to all of the winners! Note that as indicated in this thread - some of the recipients posted on another platform (with link provided here). Let's get the party started! Drum roll, please.

Just replacing old filters on this mini Corsi Rosenthal box. They have cut transmission of 🦠 in my household to zero for these past five years (we were early adopters of thanks to @corsiaq.bsky.social @jimrosenthal5.bsky.social ) also helps kiddo with his dust allergy! #CleanTheAirWeShare

There is a trend to include both App J of ASHRAE 52.2, and ISO 16890 in ASHRAE standards. Both show a drop in efficiency of used electret filters. Here we find that CR Boxes with 4- and 5-month-old MERV 13 filters produce clean room levels in 15 minutes. www.texairfilters.com/testing-air-...

No question that the efficiency of the filters will last longer in a CR box due to the greater media area. The same is true for a 4" filter vs. a 1" filter in your home. But that is not considered in Appendix J. It claims to define the filter efficiency in use through a test. That's the problem!

The lead article in the December issue of the ASHRAE Journal is: "How do Particle Filters Work?" It claims that used MERV 11 filters show substantial decreases in efficiency. Independent tests of used MERV11 filters show otherwise. This article explains: www.texairfilters.com/how-much-doe...

Waving goodbye to 2024 In summer 2024 I had the honor of giving closing remarks at Indoor Air 2024 in Honolulu. My presentation was on lessons learned from the COVID-19 pandemic (that did not imply it had passed). I'll post some of those lessons in the coming days.

Please remember that there are ways to gather that reduce the risk of spreading airborne illnesses such as #COVID. The DIY #corsirosenthalbox can make the holidays safer for everyone. @corsiaq.bsky.social @jimrosenthal5.bsky.social

@adamwong.bsky.social It looks to me like the MERV 13 filters do pretty well on the 1um-5um particles. They certainly have been proven to work in DIY CR boxes at a very low cost. I like your product, but it is noisy. What is the CFM at 35 dB?

Many thanks for the warm welcome I have received from so many since I joined bsky. I am looking forward to many good IAQ discussions in this forum. For now, I am continuing to us Twitter. The much larger audience gives more impact for my pet projects like the Corsi-Rosenthal Foundation.

Thanks, Dustin. And we are all so fortunate that you moved to IAQ & have become a research leader & spokesperson in the field! Did not remember the photo. IA2016 in Ghent, Belgium. I can say a lot about polyurethane foam clown noses! Increased exposure to some SVOCs & decrease for others!

hanks to a generous donation from 3M, the Corsi-Rosenthal Foundation has filters available for organizations wanting to make CR boxes for schools, safe air centers, churches, etc.. Just apply!

Looking forward to enjoying blue skies and many sunny days!