Air purifiers promise clean indoor air by filtering particles such as aerosols, pollen, fine dust and odors. Stiftung Warentest examined how good the cleaning performance of the devices really is. We show the test results.
Air purifiers are designed to filter particles, odors, pollen and pollutants from indoor air, which is especially beneficial for allergy sufferers. On top of that, they are also said to be effective against viruses that are transmitted by aerosols. Stiftung Warentest has awarded the “test-Issue 01/2022 examines how good the cleaning performance of various air purifiers really is. We present the results and test winners in detail and explain how the devices work.
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Stiftung Warentest: How it was tested
Seven air purifiers with filters were examined, which according to the suppliers are suitable for rooms up to at least 40 square meters and filter between 300 and 500 cubic meters of air per hour. The greatest focus in the test was naturally on air purification, especially with regard to pollen, formaldehyde and aerosols. In addition, handling, environmental properties, safety and the data transmission behavior of the associated apps played a role in the overall score in the air purifier test.
Air purifier in the test: The results at a glance
The result of the 2021 test is even more sobering than the test results of the previous year. While in March 2020, two air purifiers were awarded the overall rating “good”, the other two were rated “good” only one of the models tested managed to achieve this: the “good” air purifier Xiaomi Mi Air Purifier Pro receives the “test-Quality rating “good (2.3) and is thus the clear test winner. It is the only device that effectively filters all particles from the air. The air purifier from Medion , Philips, Ideal , Levoit and Co. all achieve only a “satisfactory” in the test.
Best air purifier in the 2020 test was the Philips AC2889/10 . It got the “test”-quality rating “good (2.4)”. According to Stiftung Warentest, it is comparable in quality to the new test winner. Only in the filtering of formaldehyde it performs slightly worse.
The new test winner: air purifier from Xiaomi
The test result: The Mi Air Purifier Pro from Xiaomi has been awarded the overall rating of “good (2.3)” the clear winner in Stiftung Warentest’s air purifier test. Only with him the cleaning performance is convincing with all particles, i.e. pollen, aerosols and formaldehyde. Less pleasing are the clear deficiencies in the data transmission behavior of the app.
Product details: The air purifier from Xiaomi is suitable for rooms with an area of up to 60 square meters and frees the air from particles, hair, dirt and other pollutants. A three-layer filter consisting of a pre-filter, activated carbon filter and EPA filter is used for this purpose. The Clean Air Delivery Rate (CADR) is 500 cubic meters of air per hour, which is the maximum amount of air that can be cleaned in 60 minutes.
The operation of the air purifier can be done with the help of the Mi-Home app, for example, with a smartphone from a distance. In addition, voice control is also possible. In automatic mode, the device adjusts the fan power depending on the air quality. Temperature, air quality and humidity are displayed on the OLED display. The display is dimmed in idle mode and the model works more quietly, so it is also suitable for night use.
Manufacturer Xiaomi recommends changing the filter every three to twelve months to ensure a consistently high cleaning performance. Replacement filters can be easily purchased.
The runner-up: Air purifier from Medion
Test result: With the “test-Quality rating “satisfactory (2.6) the Medion air purifier comes in second place in the test. Its cleaning performance, especially with formaldehyde, is less convincing. On the other hand, it performs better than the test winner in terms of handling, environmental properties and the data transmission behavior of the app.
Product details: The air purifier from Medion is suitable for room sizes up to 72 square meters. For the removal of pollen, odors, fine dust and other pollutants, a filter system consisting of pre-filter, activated carbon filter and HEPA filter is used. The cleaning performance is up to 345 cubic meters per hour (CADR).
The device has three speed levels, a colored air quality display, a practical timer and a particularly quiet sleep mode. The Medion air purifier is controlled via the touch control panel, the app or also with the voice assistants Amazon Alexa or Google Home.
The automatic reminder to change the filter is particularly useful in everyday use: depending on the quality of the room air, the model automatically reminds you to change it to ensure the best possible filter performance. Replacement filters can be easily reordered.
The best formaldehyde filter in third place: Air purifier from Ideal
Test result: With the total mark “satisfying (2,9)” the AP30 Pro from Ideal takes third place. The Stiftung Warentest testers were particularly impressed by the formaldehyde filter performance of this air purifier: Here, the device from Ideal is the best in the test. It also works more quietly than the models from Xiaomi and Medion.
Product details: With its filter system of pre-filter, activated carbon filter and HEPA filter, the air purifier from Ideal is effective against chemicals, odors and fine dust, pollen and aerosols, among other things. The compact device is suitable for room sizes up to 40 square meters and has a maximum cleaning performance of 300 cubic meters of air per hour (CADR).
Three levels, an automatic and a turbo function are available with this model. A sleep mode is also available. The setting is made at the touch of a button or via app. The latter can also be used to control other features, such as the timer or the parental controls. In addition, the filter status can be viewed via it.
The manufacturer recommends changing the filter about every twelve months. Replacement filters can be easily purchased for this unit as well.
The test winner from 2020: Air purifier from Philips
Test result: The Philips AC2889/10 already received the “test” in March 2020-Quality rating “good (2.4)” And also proved effective against aerosols in the post-test from March 2021. According to Stiftung Warentest, it can keep up with the new test winner from Xiaomi on almost all levels, only filtering formaldehyde from the room air worse.
Product details: The Philips air purifier has a filter system consisting of a pre-filter, activated carbon filter and HEPA filter. Its cleaning capacity (CADR) is 333 cubic meters per hour. It cleans a room with 20 square meters in just nine minutes. The good performance makes it suitable for room sizes of up to 79 square meters.
It can be operated directly on the device or with the help of an app or Apple’s voice assistance Siri. It has different power levels and a sleep mode. Practical for allergy sufferers: via the app you receive information about the current air quality, pollen count and allergens on your smartphone. A display shows the quality of the room air by means of a four-stage LED color ring also directly on the device.
The pre-filter is washable, HEPA and activated carbon filters can be purchased as replacement parts. Both are also available in a practical filter set . According to the manufacturer, the activated carbon filter lasts one year, while the HEPA filter only needs to be changed every two years.
Our conclusion to the air purifier test
Often rooms are so polluted by odors, pollen, fine dust, allergens or pollutants that the air is out of order. Even at normal times, a good air purifier or air washer can therefore be a sensible purchase, especially for allergy sufferers. In the Corona pandemic, the best devices can also help with prevention by filtering aerosols from indoor air.
The new test winner does it best Xiaomi Mi Air Purifier Pro and the best air purifier from the 2020 test, the Philips AC2889/10 . But beware: even with them, there is always a residual risk. It’s true: an air purifier can reduce the risk of infection, but additional measures such as keeping your distance and wearing mouth-nose protection are still necessary indoors. In addition, shock airing should be done regularly.