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Air purifiers and asthma

We've joined with Asthma Australia to look at what people with asthma should know about air purifiers.

CHOICE staff
CHOICE staff

During the 2019/2020 Black Summer bushfires, we know that people with asthma relied on air purifiers to keep indoor air clean from smoke and fine particles.

We also know that during this time air purifiers were in high demand.

Here at CHOICE, we put air purifiers through serious scientific testing, sealing them in a room to measure how well they clean the air of dust, smoke and other irritants that can trigger asthma.

We've found the best ones can quickly clear significant amounts of dust and fine particles, such as PM2.5, while the worst don't make much difference at all, so it's worth doing your research before you decide to buy.

To help you understand what to look for in an air purifier, and which ones to consider, we're making our test results available for Asthma Australia's members – simply enter your email address below.

How does an air purifier work?

An air purifier is basically a fan, with filters inside. The air in a room is sucked into the purifier and passes through filters that trap any floating particles, 'cleaning' it.

Can an air purifier help with asthma?

An air purifier removes some common household allergens from the air that may trigger asthma, like dust, pollen and mould. 

Reducing exposure to these allergens may improve your asthma control and make symptoms easier to manage.

An air purifier can also clear the air inside your home of bushfire smoke, another trigger for asthma.

This could be worth considering if you're vulnerable to smoke from seasonal fires, for example if you live in a bushfire risk zone, or area commonly managed for hazard reduction burns.

Join Anthony Flynn from Asthma Australia and Chris Barnes, CHOICE product tester, talking on how to be smart about air quality.

Do you need one?

While it can help with airborne irritants, an air purifier is no silver bullet, according to Chris Barnes, our air purifier testing expert at CHOICE. 

It will have no effect on dust on floors or furniture – so you'll still need to clean floors and soft furnishings regularly.

Think of an air purifier as one of several measures you can take in avoiding allergen and irritant exposure and managing your asthma.

What should you look for in an air purifier?

A HEPA (high-efficiency particulate air) filter is the most important feature in an air purifier.

It traps small particles, invisible to the naked eye. HEPA filters can trap at least 99.95% of the dust, smoke, mould and other particles in the air.

We recommend using our lab results to choose a model that rates high for removing both dust and smoke.

While we don't directly test for pollen, our experts say any model that performs well for removing dust will remove pollen too.

And size matters. Look at the recommended room size on the air purifier and consider getting one rated for a slightly larger room.

That way it will still clear the air comfortably on its lowest (and quietest) fan speed, when you're trying to sleep.