How to buy the best air purifier - test and review

There are a number of things you need to ask when buying an air purifier. Check out our latest air purifier buying guide to help make the right choice for your home.

Plus here’s our air purifier review (member content).


Dust, smoke and pollen helped us find the the best air purifiers. Here’s what we found (member content).


Very relevant at the moment for those with airway issues and affected by the bushfires


Where did I see something about the Xiaomi unit? I thought it was in Choice testing but apparently not :frowning:

Good intro to air purifiers. I see that the focus is on room-only units.

With bushfire smoke everywhere, it is really worth considering a whole-house unit. My whole-house purifier works 24x7 to keep the air clean (tested with a particle counter) for my whole family. It’s got a medical-grade HEPA filter and it’s very cheap to run. So much better than any in-room unit I’ve tried.

I wrote a blog post about my experiences.

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Hi @kranix, welcome to the discussion.

You raise an interesting option.
That of applying clean air filtration (external pressurisation fans with filter panels is one method) to a whole building. It has been briefly raised in a similar discussion.


I have not been able to quickly locate any details of systems for small scale residential properties.

The rooms or buildings are pressurised by small fans that move outside air though cleanable filters to the inside. This provides clean filtered fresh air and can be vented through leakage around doors and windows, exhaust vents or even open windows/doors.

Perhaps a modification and upgrade to the filtration in a residential ducted air conditioning system might also provide a suitable solution.

Hi @mark_m,

I was prompted to research air filtration to manage my own asthma and allergies.

I’m extremely happy with my whole-house air purifier. It comes from comes from Sanctuary Air. By creating positive air pressure, it keeps out dust and improves air flow (reducing the need for air conditioning). I’d highly recommend it to anyone.

It’s got a single fan and only uses about 100W of power. But it’s specifically designed for filtration, so I’d expect it to be a lot more efficient than retrofitting an air conditioner. A good HEPA filter can slow down the air flow considerably, and you’d need a good seal around the filter so that the unclean air doesn’t take the path of least resistance around the filter. Another point to consider is that my purifier is expressly designed to run 24x7, whereas an air conditioner is only designed to run periodically.

However, the purifier can use existing ductwork. Mine uses the same vents as my central gas heater. that saved a fair bit of money in the installation.

Happy to assist further if you’re interested.

I’m interested in helping others learn there are strategies other than free standing air filtration/conditioners (purifiers in marketing spin). Others may find this discussion very useful.

I’m familiar with industrial scale solutions which include buildings housing electrical and electronic equipment that is dust sensitive. At the extreme end of this scale are various systems used for clean rooms, isolation and hospital theatres.

In comparison,
The common in room free standing residential units offer a simple quick solution. Although as the discussion in this and a related topic suggest the value and performance of some of the free standing units is doubtful.

There is a difficult discussion not yet had concerning humans living entire lives in hermetically sealed housing and transport systems. The alternative is to open the windows and let the air flow through the house for cooling and freshness. I know the latter is a bit challenging for the home beautiful set and not wise for those with certain allergies.

Apologies for the late reply – I missed the notification.

I started with freestanding units, and upgraded to the whole-house after further experimentation and research. In the end, it’s a lot more efficient and cost-effective.

A good whole-house unit will create positive air pressure and will filter all incoming air through a medical-grade HEPA filter. So all of the air in the house will be extremely clean and it will be difficult for foreign bodies to infiltrate. Not quite hermetically-sealed, but perhaps more practical because we still need some flow of fresh air to stay comfortable.

My unit gives me a choice of fan speed and intake sources (return/recirculate, roof cavity, and fresh from outside). I mostly just leave the fan speed at its highest (the power usage is negligible) and the intake sources on the first two. This distributes heated/cooled air around the house, and during the winter it improves my thermal efficiency by moving heat lost through the ceiling back into the living area.

It takes some discipline to keep the doors and windows shut. That also impacts what kinds of heating and cooling you should have. Reverse-cycle air conditioning is good because it recirculates existing air. Evaporative cooling is awful because it brings in air en-masse, bypassing the air filters.


I did heaps of research into the science and available implementations, and Sanctuary Air came out well on top. I’ve had mine for close to a year and the difference has been enormous. That’s through the allergy season and the recent bushfires. And tested with particle counters (PM10, PM2.5, PM1).

If I’m advocating for anything, it’s for air quality to be taken seriously and for people to be able to make informed choices. Education is the answer. I understand that whole-house filtration is (currently) a niche market, but I believe it ought to be more widely known by consumers.

Looking at the scientific literature (easy enough to find through Google), the only genuinely proven method of purifying air is a HEPA filter . Hospitals, for instance, often use H13 grade filters. Inferior filters such as “HEPA-like” and MERV will provide far less protection. There are other technologies promoted by manufacturers, such as UV light and ionisation. As implemented in consumer devices, their effectiveness is unproven. They appear to exist for marketing purposes only.

A filter loses its effectiveness if there are other ways for air to infiltrate the area/home. The same principle applies to face masks: the mask must form a perfect seal around your nose and mouth, or else the unpurified air will take the path of least resistance. A room purifier will be of limited ability because untreated air can still come in from anywhere. It doesn’t magically create a ‘bubble’ around you or for the room.

The way to combat that is to create positive air pressure , so that air is constantly pushing out of the cracks in the room/house. That way, particles cannot get in. In real-world practice, this needs to be done on a whole-house level. This is just basic physics, no marketing voodoo here.

So that leaves us with two main principles: medical-grade HEPA filtration combined with positive air pressure for the whole house. And I question products that market technologies that have been scientifically unproven/disproven in a practical residential context.

There aren’t many offerings in Australia that meet this criteria. And that’s why I was so enthusiastic to suggest a particular solution. Australians have taken air quality for granted, and were caught completely by surprise by the recent bushfires. There was so much false information being circulated, creating a serious danger to public health. So until very recently, air purification was a very niche business in Australia. In-room units mostly come from overseas, and whole-house purification is still almost unheard of.

It’s been a year since I did my market research, so I’m going from memory. I don’t believe the market has changed much in that time. Don’t forget to calculate the total cost of ownership – electricity, replacement filters, labour, etc. There’s a company called Ventis, but their filters are not good enough (MERV14) and their pricing was twice as much (and even more when maintenance was considered). IQAir is probably the closest alternative I’ve seen, but again they are very expensive. There are others that aren’t even available in Australia.

Strapping a HEPA filter to an existing ducted air conditioner would not be suitable either. It would massively reduce its heating/cooling power and it would not be economical to run 24×7. It’s just not designed for that.

And of course, you should measure the particles in the air both before and after the solution has been implemented. If it’s working as intended, the difference in PM10, PM2.5 and PM1 particles will be significant. During the recent bushfires, for example, I saw outdoor particle counts at dangerous levels outdoors but nearly nil indoors.

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Similar to the solution that you implemented, and an add on for an existing ducted system. It is certainly a niche option.

It appears that there are other manufacturers, certainly available in the USA, high is food for thought about the market.


Yes, that’s the IQAir system I was referring to. It does look pretty decent, although their filters are MERV16 which aren’t HEPA grade. If I recall correctly, the total cost of ownership (including installation and ongoing maintenance) was more than twice that of the Sanctuary Air system that I got.

Mine is also an add-on system, using the ducts from my central gas heater. I opted to also have dedicated ducts for two important rooms. This can be beneficial, since there are some downsides to sharing ducts (no matter the system).

And yes, there are other products that are available overseas. But you’ll want one that is fully supported by a local installer and meets Australian standards

Before our recent bushfires incident, the prevailing opinion in Australia was that even our city air is not polluted enough to justify purification. So there wasn’t a market here. Demand may have changed, but the market hasn’t really caught up.

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From the user @nads


Very topical at the moment if you live near all the bushfire fallout in NSW or Qld.

Our main household aircon came with additional filters to remove odour or purify the air. It may be worthwhile also considering how effective these additional filters are when fitted and whether they have a negative impact on the performance of the aircon?

A split system room air con may be just as effective as a dedicated ‘air purifier’. No added cost! Some purifiers appear to be little more than a coarse filter. With a bottle of scented water in the tank they can increase room humidity, while masking any background odours with your preferred fragrance.

I dislike fragrance, fresh mown wet grass a close second, although BBQ steak or bacon and eggs, might be a compromise I could live with. To each their own.


I’m looking for an air purifier myself, due to ongoing thick smoke, which does get into the house every time you go through the door, plus no doubt around and under doors and through the roof access hole etc.

With no testing, it leaves me a bit in the dark as to what is a good product and what has good marketing, but is crap!

I was looking at this one:

but note in the specifications that it requires 240V 60Hz power. I’m not sure where you might find such power, as we are supposed to have 230V 50Hz in Australia.
The warranty also says it is not covered by connection to an incorrect power source. Maybe that specification is in there to avoid all warranty cover!

It could be a misprint, but you’d expect they should be able to get such a basic spec correct.


As other countries have 240V/60Hz, maybe Appliance Online has imported a product which was specifically made for another market and used the brochures prepared for these other markets.

It would be interesting if they denied a warranty claim due to the device being plugged into an Australian power point. If they did deny a claim on such grounds, I expect that the likes of the ACCC would be interested. If a product is marketed by an Australian business to Australian’s, one would expect that it would be fit for purpose and meet the Australian operating environment.


Or how else would it pass the Electrical Standards requirements to be sold here legally.


This is what I’m trying to filter out, visibility ~3km


Our’s is almost as bad, one day about a week and a half ago it was a yellow day because of the smoke haze everything had a yellow tint.


Ha! I tried to use their (anything but) “Live chat” , and had no response to my question about the power requirement. It did make them remove it from their site though!

Unfortunately, this product is not available, but you may also like …


The Japanese are big on air purifiers. Panasonic, Haitachi etc.

One sample

Google or Apple seem to translate most of the web site, although the long marketing spiel gets distorted by differences in grammar and common expression.

It seems that our market in Oz is a little less attractive, hence what appear to be a proliferation of products of doubtful performance.

The Asthma Foundation has a number of recommended products that might be a useful resource, as they are keen to reduce airborn dust and pollens.

In searching for products I gather the secret is to search for those that have a Sensitivechoice approval.

Daikin and Sharp have a number of options that on specification appear capable.

Agree it is unfortunate there appears to be no local product testing to back up the product effectiveness. That our houses mostly leak air, suggests even a quality air filter will only reduce over time, but not eliminate the hazard.

Industrial environments with high dust loads typically force ventilate work spaces. The air filtration systems take the dust etc out of the air before it is pushed into the ventilated spaces. The strategy is to never let the dust in to need to remove it. There are smaller scale add in systems available that might suit some of us for a longer term and more effective solution.