Can Air Purifiers Prevent the Spread of COVID-19?

Air Purification

An air purifier system works by drawing air in the unit, passing it through a filter, then expelling the clean air. The filter is what captures micro-particulates, including pollen, cooking fumes, dust, and bacteria.

Removing these tiny particles can improve air quality substantially. Those with allergies will experience fewer symptoms. People with chronic lung problems will find it easier to breathe. The improved air is suitable for everyone in the household.

The Reality of Air Purifiers and the COVID-19 Virus

Viruses are tiny. The primary filters capable of capturing viruses are HEPA filters. They are effective at capturing 99.97% of particles down to 0.3 microns in diameter. The COVID-19 virus is 0.125 micron in diameter. Unfortunately, that's too small for a HEPA filter to capture directly. Hope is not lost, however.

Those with the COVID-19 virus can spread it via water droplets released when coughing, talking, breathing, or sneezing. These water droplets measure around 1.0 micron in diameter. This is large enough for the HEPA filters to capture them. The next issue is how to get those droplets through the filter. That's where an air purifier's clean air delivery rate (CADR) number comes into play.

A CADR tells you how fast it can clean the surrounding air at its highest speed setting. Most air purifiers have three CADR ratings for smoke, dust, and pollen. Smoke particulates are about the same size as virus particles, so that's the rating you want to pay attention to. You need a CADR of 240 or above to circulate a room's air about five times per hour. That's the minimum you need for effective reduction of virus droplets in the air.

Specific Uses for Air Purifiers to Prevent COVID-19 Spread

Suppose someone in your family has COVID-19 and is quarantining at home. In that case, an air purifier may help protect caregivers and other family members. It's also an option for healthcare workers who self-quarantine when at home. The air purifier needs to be used within the quarantine space, with doors and windows closed. It should run 24 hours a day.

It should be placed within three feet of the sick person at the highest setting that won't disturb sleep and recovery. This gives the highest chance of capturing the virus before it spreads to caregivers and family members.

For more information about air purifiers and how to keep your indoor air fresh, call TDI Air Conditioning today.