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How to buy the best air purifier

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.


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.

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.