Anything you breathe in, other than air and water vapour, is a pollutant. This includes dust, pollen, smoke, volatile organic compounds (VOCs), and pet hair and dander.
If you or anyone in your household battles allergies or asthma, you’ll be all too familiar with how these pollutants can affect health. For some people, an air purifier isn’t a luxury, it’s an essential household tool.
We tested six air purifiers, ranging from $260 to $749. While most of the brands talk a good game, our testing uncovered a big gulf in performance between the best and worst models.
What to consider
While the filter is the most important part of an air purifier, there are additional features that can aid in cleaning the air you breathe.
Check the recommended room size (most models have m2 ratings). A larger-than-required model won’t have to work as hard to clear the air, which also means it should run more quietly.
HEPA filters are the mainstay in air purifiers, so make sure your chosen model has one. They can trap particles down to 0.3 microns (a human hair is about 80 microns), which should deal with most airborne nasties.
An ioniser works by using a high voltage to put a charge through airborne particles to make them static. This makes them attracted to grounded objects, which removes them from the air.
Charcoal filters remove odours and they can help absorb VOCs.
Pre-filters are a layer of defence in front of the main purifying filters. They help catch larger bit of debris to stop the finer filters from getting clogged up too quickly.
Sensors and timers
An air purifier with a built-in pollution sensor will continuously sniff the air to check the quality. A few models will switch on and work to rid the room of pollution once they detect any contaminants. In the absence of automatic sensors, the purifier will chug away non-stop, so look for a model with a timer so you can set the unit to run at certain times of the day.
A good range of fan speeds is important for quickly clearing all parts of the room, as well as having some quieter settings for when you go to bed.
Features to ignore
Ozone air treatment is all marketing huff as many studies have shown it to be ineffective at treating airborne contaminants. We consider it a relatively useless feature.
Manufacturers claim UV light can kill bacteria. While UV light is proven to sterilise water, studies have shown a lack of effectiveness in domestic air purifiers.
We've tested 6 air purifiers.
Find the right one for you.