Why This HEPA Filter Stopped My Family From Coughing in Seoul’s Yellow Dust Season
Last spring, I watched my youngest son wake up with a dry cough for the third morning in a row. Our apartment in Mapo-gu, Seoul, was sealed tight, but the fine dust (PM2.5) still found a way in. I had tried cheap filters from a local market, only to realize the airflow dropped by half … Read more