Recently, I built a Corsi-Rosenthal (CR) box for our house. If you’re unfamiliar with the CR box, it’s a homemade air purifier that can remove a significant number of viruses, allergens, and other beasties from the air we breathe. The design was created by Richard Corsi and Jim Rosenthal, and has sparked a beautiful wave of DIY science and engineering, especially when we engage students in their design and construction.

The Corsi-Rosenthal Box that helps clean the air in my home.

Why bother? Well, my house is older, and we don’t have any built-in air filtration system. The days are getting longer and colder, so keeping the windows open with fans isn’t comfortable, and my husband and stepkids have all returned to classrooms.

As the number of inhaled viruses or aerosol particles that contain the virus increases, the probability of infection increases…If it is inhaled it can deposit in the respiratory system. Period. Your immune system does not care what pathway it took to get there.
Richard Corsi, The Dose Makes the (risk of) Infection

And why does this matter? Although we are all vaccinated and boosted, we are still at risk for breakthrough infections and thus infecting others who may be more vulnerable than us:

A breakthrough infection is an infection with a virus, bacterium or other germ after you have been vaccinated. This is an expected occurrence for a small percentage of those receiving any vaccine, since no vaccine for any disease is 100% effective in preventing infection in every person who receives it.
Drs. Lisa Maragakis and Gabor David Kelen, Breakthrough Infections: Coronavirus After Vaccination

Plus, I’m enjoying not having had a cold that then morphs into a sinus infection, bronchitis or pneumonia in 2.5 years. I like being masked so I can lip synch to the soft rock piped through the grocery store sound system, without numerous questioning looks from passerby. More importantly, if doing a few small things like a mask indoors or getting a needle can help others from getting sick, why wouldn’t I?

But I look at my CR Box, and wish it was…I dunno, prettier? The white tape I used blends well with our decor, but there are people on the interwebs who are showing up. So if you’re interested in building one, but want more pizzazz, here’s a few examples to spark your own creativity.