Air Purifiers Still A Good Choice To Fight Covid Especially In Enclosed Areas

work from homeAre you wondering if having an air purifier can help you reduce the chance of infecting with the covid virus? Read on as we learn from what the experts say.

With reference to straits times article “No need to use air purifiers at home, natural ventilation is key to reducing risk of Covid-19: NEA” published on 6 Jun 2021, it says air purifiers cannot substitute  good ventilation. If your home has good ventilation and windy, then probably you wouldn’t need an air purifier.

In the same article, it also states:

“But this does not mean that air purifiers have lost their value. They can still be used as an interim measure in enclosed, poorly ventilated spaces with a high risk of disease transmission, such as where masks are removed, or at medical procedures such as swabbing.”

So this means if you are working from home or offices that are enclosed (windows closed or air-con), it could be a wise choice to have air purifiers in your area.

In the same article,

Associate Professor Ernest Chua from the National University of Singapore’s Department of Mechanical Engineering said: “The use of portable air purifiers with an efficient Hepa filtration system can certainly help to reduce the risk of airborne transmission of Covid-19. “

Besides reducing the risk of getting covid, a good HEPA air purifier can also help to:

  • Remove indoor allergens. This can help to improve the quality of life for people with allergies.
  • Reduce asthma occurrence. The air purifier can help to remove odor and chemical pollutants which are the triggers for asthma.
  • Remove smoke. If you have someone else smoking in the room, the air purifier can also help to clean the air. To a certain degree, it also helps when your hose are affected with second-hand smoke.


Only purchase air purifier with HEPA filter

The reason why most people (and even experts recommended) choose air purifier with HEPA filter is because this kind of filter can trap particles as small as 0.3 microns. To give you an estimate, a human hair is typically about 100 microns.

Thus, when an air purifier uses a HEPA filter, it can remove 99.97% of the particles in the air.

Personally, I feel Xiaomi air purifier is the most affordable and efficient one that has good specifications.

It can clean an area of 48 meter square (which is equivalent to a typical study room). It also has a CADR (Clean Air Delivery Rate) of 400 metre cube / hour.

Xiaomi recently also introduces a new filter that can help to filter virus and materials in the air.

xiaomi air purifier anti-bacterial filter


If you want to get an air purifier for your home, you can consider this Xiaomi Air Purifier 3H. You can also buy future filter replacements here.

Hope you find this article useful!

What is PSI?

PSI stands for ‘Pollutant Standards Index’. It is an index to provide accurate and easily understandable information about daily levels of air quality.

PSI is computed based on 24-hour average of PM2.5 concentration levels, among other pollutants. PM2.5 is the dominant pollutant during haze episodes.

The ambient air in Singapore is monitored through a network of air monitoring stations located in different parts of Singapore.

The monitoring stations measure concentration levels of particulate matter (PM10), fine particulate matter (PM2.5), sulphur dioxide (SO2), nitrogen dioxide (NO2), ozone (O3), and carbon monoxide (CO). These six pollutant parameters determine the PSI.

The PSI value gives an indication of the air quality as shown:

PSI Value PSI Descriptor
0 – 50 Good
51 – 100 Moderate
101 – 200 Unhealthy
201 – 300 Very unhealthy
Above 300 Hazardous

Technical details on how the PSI is calculated can be found here: Computation of PSI