With increasing concerns about air quality due to wildfires and the ongoing pandemic, searches for “air purifiers” have spiked on Google. However, alongside the surge in interest for commercial air purifiers, a DIY trend has emerged, capturing the attention of social media users on platforms like TikTok and Facebook. The technique, known as the Corsi-Rosenthal method, has gained popularity in recent years, offering an affordable and effective solution for purifying indoor air.
The Corsi-Rosenthal method involves using a box fan in combination with air filters to create a makeshift air purifier. The method has gained particular attention in regions heavily affected by wildfires, such as the western United States. East Coast residents, who are less accustomed to dealing with wildfire smoke, are now discovering this DIY solution for the first time.
Social media has played a significant role in popularizing the Corsi-Rosenthal method. Videos and posts demonstrating how to build these DIY air purifiers have gone viral, reaching millions of viewers. One TikTok video by Seattle resident Angel Robertson, showcasing the construction process, has gained over 600,000 views. In the video, Robertson duct tapes four 20-by-20 air filters into a box shape and attaches a fan on top, creating an inexpensive apparatus that costs under $100.
Public health experts have weighed in on the effectiveness of Corsi-Rosenthal purifiers, noting their ability to efficiently remove particles from the air. Petri Kalliomäki, a postdoctoral researcher at the University of Maryland’s School of Public Health, emphasized that these purifiers have a relatively high clean air delivery rate. They can effectively purify the air, not only from smoke but also from pollen and viruses.
Misti Levy Zamora, an assistant professor in public health sciences at the University of Connecticut, has conducted tests on Corsi-Rosenthal purifiers. Zamora and her colleagues have even distributed these DIY purifiers for free to individuals stopping by their university. Zamora confirmed the purifiers’ efficacy, stating that they were able to filter out all airborne particles within minutes.
The invention of the Corsi-Rosenthal box was driven by the power of social media. Co-inventor Richard Corsi, the dean of the College of Engineering at the University of California at Davis, shared his sketch of the design on Twitter in 2020. Jim Rosenthal, CEO of Tex-Air Filters, saw the design and built it. Corsi aimed to create an affordable purifier accessible to the average American. He has since received feedback from friends in the Northeast who have adopted his idea.
Individuals like Grace Turner and Liz Hradil have embraced the DIY air purifier trend. Turner, inspired by her time in Salt Lake City, built her own box fan purifier and shared it on TikTok, where she noted the positive impact it has had on her home. Hradil, living in Syracuse, New York, sought relief from the recent smoke influx and discovered the Corsi-Rosenthal box online. After building her purifier using filters and a fan from a local store, she quickly noticed the disappearance of smoke odors within 30 minutes.
The growing popularity of DIY air purifiers underscores the need for accessible and affordable solutions to address indoor air quality concerns. While commercial air purifiers remain widely available, the Corsi-Rosenthal method offers an alternative for those seeking a cost-effective way to combat smoke, allergens, and airborne contaminants. As the demand for cleaner air continues to rise, these DIY purifiers serve as a testament to the ingenuity of individuals seeking to protect their health and well-being in the face of environmental challenges.