Yes, these are relatively large particles. Your CR box will easily filter out any airborne pastel dust.

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

YouTube video by UC Davis College of Engineering How to Build a Corsi-Rosenthal Box

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?...

Agreed the standardized tests are a very valuable to assess additive air cleaners. The choice to use a picture of a CR Box - an air cleaner that removes contaminates - is unfortunate.

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

The same type of charlatans are active in the indoor air world. There are plenty of cures for the air very few of which work, but the theory is the same costly non-effective and and wasting time.

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.)

These DIY air purifiers could make clean air more accessible during wildfires As wildfires rage across the country, smoke plumes from scorched structures pose a major health threat. Sneaky particles can creep through vents and other home openings, but buying high-quality HEPA f...

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

Does outdoor air pollution affect indoor air quality? It could depend on buildings’ HVAC - @theU Using the U campus itself as a lab, researchers conclude inversion and dust pollution is kept out of buildings, but wildfire smoke can sneak inside if efficient 'air-side economizers' are in use.

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.

These DIY air purifiers could make clean air more accessible during wildfires Homemade air purifiers can filter air faster, making them an affordable alternative to more expensive commercial products.

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!

It is pretty hard to beat the particle counter you have for price. (less than $100). I also like it because it gives the size bins by number - not just PM. It's not the most accurate, but OK for most purposes. I also use Dylos, Qingping and Air Knight. Dylos works the best for me.

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 Help Corsi-Rosenthal Foundation reach their goal by donating or sharing with your friends.

🧵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...

Using a Corsi-Rosenthal Box to Remove Wildfire Smoke? Make Sure to Use the Right Filters - Tex-Air Filters By Jim Rosenthal Much of the Eastern United States is covered with wildfire smoke from the massive fires in Canada. A very effective way to avoid this respiratory hazard is to keep the windows closed ...

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!

Welcome - Corsi-Rosenthal Foundation Dedicated to providing cleaner safer air for all.

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

Image of a dean pointing at a professor who appears to be stealing his Corsi-Rosenthal Box. Both are wearing masks.

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.

Corsi Rosenthal box. https://corsirosenthalfoundation.org/

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