Air Filter 要買機械過濾的，不要產生Ozone的。 或者買air quality monitor

https://ireadlabelsforyou.com/mobile-air-purifiers-guide/

list of California certified devices: https://ww2.arb.ca.gov/list-carb-certified-air-cleaning-devices

https://www.amazon.com/Atmotube-Professional-Formaldehyde-Temperature-Barometric/dp/B07WD5GGZK