Air Cleaners (purifiers) – which one to buy?

We know that during the 2019/2020 Black Summer Bushfires people were desperate for any reprieve from the smoke, including purchasing air purifiers which were in high demand to try to keep the smoke at bay and to create clean air shelters in their home.

What do air purifiers do?

Air cleaners (purifiers) use a system of internal fans to pull the air through a series of filters that remove airborne particles. The air cleaner then circulates the clean air back into the room.

Types of filters

According to Choice, there are many different types of air cleaners and multiple filter types, though not all filters are created equal.

  • HEPA filters: High-Efficiency Particulate Arresting (HEPA) filters are considered to be the most effective filters at targeting common allergens. HEPA filters remove at least 99.95% of allergens and pollutants.
  • Activated carbon filters: These filters use activated charcoal to clear smoke, chemicals, and odours from the air. However, they don’t filter allergens and bacteria and need to be replaced frequently.
  • Ozone filters: This filter can help remove odours, including the smell of smoke, but they don’t remove allergens or pollutants such as fine air particles.
  • Ionic filters: Ionic filters use an electrical field to remove pollutants from large areas. While they are somewhat effective, they produce ozone, a type of pollutant, and release it into the air.
  • Ultraviolet (UV) filters: UV filters can kill bacteria. However, in order to work, most bacteria need to be exposed for an extended period of time – much longer than most purifiers allow.

Do Air Purifiers actually work for bushfire smoke?

An air purifier equipped with a HEPA filter can remove more than 99% of the fine particles (such as PM2.5) in the air. The protection offered by air cleaners can range from low to very high. As with filtration systems, the level of protection depends on the type of air cleaner you have. Those equipped with HEPA filters are much more efficient.

Things to consider

  • When choosing an air purifier, the most important factor to consider is the type of filter (or filters). Look for an air purifier that has a HEPA filter.
  • Be mindful of the room size it claims to filter when purchasing. They are only useful for use in isolated places and not a safeguard covering the whole house.
  • Prices range from around $100 for small, basic purifiers to $1,500 or more for models that purify large spaces.
  • You’ll also need to factor in the cost of replacement filters as you’ll need to replace them regularly to keep your air purifier working effectively.

Whilst Asthma Australia does not recommend or endorse particular brands, we do advise that if selecting an air purifier, you select one with a HEPA filter. CHOICE together with Asthma Australia is giving you – as an Asthma Australia subscriber – free, unrestricted access to its latest review on Air Purifiers.

If you are finding your asthma symptoms are worsening, we suggest you consult with your doctor, and in the case of an emergency call triple zero (000). If you would like assistance with the ongoing management of your asthma, you can speak to one of our Asthma Educators on 1800 ASTHMA (1800 278 462).

References – Choice; Finder