Clean indoor air can reduce spread of COVID-19 according to professor

Keeping indoor air clean can help to reduce the spread of COVID-19 according to a professor of Mechanical Engineering.

Shelly Miller, from the University of Colorado Boulder in the US, who’s daily job is as an indoor air quality researcher says that a ‘safer home’ is one that ‘constantly has lots of outside air replacing the stale air inside.’

Usually, a home’s average air exchange rate is 0.5 air changes per hour, which takes the air inside around two hours to replace two thirds of the air inside an average home. Interestingly, that means that it takes about 6 hours to replace all the air in your home.

As you can imagine, this slow rate of air exchange is not great while trying to limit the spread of the coronavirus.

The World Health Organisation (WHO) currently advocates 6 air changes per hour to help limit the spread of the disease. The best advice is to open as many windows as you can and run bathroom exhaust fans. If you are still concerned running air filters can also help.

However, Professor Miller does recommend checking the effectiveness of your air cleaner before relying on it. “Consider how effective an air cleaner’s filter is. Your best option is a cleaner that uses a high-efficiency particulate air (HEPA) filter, as these remove more than 99.97% of all particle sizes.”

For more information on the interview with Professor Shelly Miller, please visit

To learn more about Indoor Air Quality click here.