Here's how we test air purifiers.
Performance
Our air purifiers performance test is based on the clean air delivery rate (CADR) industry standard test for air purifiers.
We test air purifiers on their highest fan setting to see how quickly and effectively they clean the air of:
dust
smoke
volatile organic compounds (VOCs).
VOCs are emitted as gases from solids or liquids, including paints, cleaning products, pesticides, building materials, glues, marker pens and photocopiers.
We use fine particles of titanium dioxide to test dust removal.
We burn wood chips to test smoke removal.
We use acetone to test VOC removal.
We introduce these pollutants in a controlled way into the test chamber and mix them into the air.
First, we measure how fast these air contaminants naturally dissipate or decay in the air without the air purifier running. Then we clear the chamber and repeat the test with the air purifier running.
We calculate the percentage of particles the air purifier has removed and compare this with the natural decay rate measured without the air purifier running. This tells us how quickly and effectively the air purifier is clearing the air.
Ease of use
For ease of use, we assess how easy each air purifier's controls are to use and the clarity of labelling, the stability of the unit, the ease of lifting and moving the unit, the ease of cleaning the unit, and whether it has cord storage.
Noise
We record the noise levels in decibels (dBA) produced on the highest fan setting, so you can compare which air purifiers are quietest.
Daily running cost
We calculate the daily running cost of each air purifier, running for 12 hours, based on the energy used (kWh) and current price of electricity.
Other functions and features
We make a note of any additional functions and features each air purifier has, such as heating and cooling, and additional filters.
Our survey data
In our annual reliability and satisfaction survey, consumers tell us about faults that have left an appliance they own unusable or mean they’ve had to change how they use it. We also ask them how satisfied they are with the appliance. We use their data to produce our predicted reliability and brand satisfaction scores.
We use a statistical test to rate the relative performance of each brand. Compared with the data we have for all products of the same type from the survey, we rate each brand as highest, high, average, low and lowest for its reliability and satisfaction.
You can compare the ratings for different brands of the same product type (for example, the reliability ratings for Dyson and Breville air purifiers), but you can’t compare the results for different product types (for example, satisfaction with Winix air purfiers and Samsung phones).
We analyse brands that get at least 30 responses in our survey. That means there are some brands we can’t analyse because we don’t have enough data. For those brands, we assume they have average predicted reliability and brand satisfaction.
Our current ratings are based on data from responses about 502 air purifiers in our 2026 survey. Our next survey for these appliances is in 2028.
