General experimental setup
The Dyson was set up in a normal office room with a size of about ten square metres and a ceiling height of three metres. The door was closed at all times during the test so that no fresh air could enter from outside.
Experiment 1: How does the Dyson deal with stale air?
The test was to show how effectively the Pure Humidify + Cool deals with stale polluted air and cleans it of aerosols and particles. Intensive work was done for this in the test office. First, 90 minutes of data were recorded with the two air-Q Pro without activated air purifier. Then, starting at 12:15 p.m., the Dyson was switched on for about 60 minutes and ran at level 7 of 10 during this time.
As expected, switching on the Dyson air purifier has no effect on the carbon dioxide content of the air (Fig. 1). A minimal increase in the CO₂ content can be measured by the air-Q air sensor on the table. One possible cause could be that the Dyson swirls up the heavier CO₂ that settles near the floor and mixes it with the rest of the air. In the first 90 minutes of the test, the VOC value rises to 350 ppb due to the test subject's breathing and sweating - a slightly higher, but normal value for an indoor environment.
After the Dyson Pure Humidify + Cool air purifier was switched on, the value dropped significantly and continuously until it leveled off slightly above the initial level (Fig. 2), as VOCs are continuously produced by the test person present.
During the test, the particulatespollution was also measured. The value PM₂,₅ stands for particles that are smaller than 2.5 µm and are measured in the unit µg/m³. Particles of this size are respirable, penetrate the bloodstream and can cause diseases of the cardiovascular system. In addition, the particulate matter value PM₀,₅ was also recorded during the test. This stands for particles smaller than 0.5 µm and is recorded here in the number of particles per 100 ml of air, as the mass of these extremely small particles is negligible. These very fine particles are known as ultrafine particles and are suspected of penetrating the brain and significantly increasing the risk of diseases such as Alzheimer's.
Before the air purifier was switched on in the room, the particulates load was low and practically constant at 0.4 to 0.8 µg/m³ for PM₂,₅. The air-Q measurement analyser continues to count up to 90 particles per 100 ml of air for the particle size PM₀,₅.
The Dyson Pure Humidify + Cool was able to reduce the particulates load to practically zero after switching on. Even though the load was not too high, this still clearly indicates that it also works reliably in the ultra-particulates range- in the further course of the test, the Dyson was subjected to a particulates hardness test.

During the entire test, the air-Q also recorded temperature and humidity, among other things. After switching on the Dyson air filter, the temperature curve flattened significantly downwards. There are two explanations for this: possibly the temperature difference in the room was reduced by the air turbulence and thus decreased at the level of the air-Q air analyser standing on the table. Another possibility is that the temperature has been reduced by the evaporative cooling of the water in the Dyson Pure Humidify + Cool. This would also explain the desired increase in humidity during operation of the Dyson. In any case, the temperature became noticeably lower as well as more comfortable after the Dyson was activated.

Regular office work (typing, clicking) carried out in the room during the test resulted in a noise level of just under 42 dB on average. After switching on the Dyson Pure Humidify + Cool, our measuring device recorded an increase in the measured volume to a still quiet 48 dB. The distance between the air-Q and the air purifier was about two metres.

Here is our everyday test in fast forward:
Experiment 2: How does the Dyson handle heavily particulates-contaminated air?
In order to contaminate the air in a controlled manner, a smoking manikin was set up and lit. The air-Q triggered a fire alarm after barely ten minutes because the particle load from the smoke in the small room was so high that the air analyser assumed it was on fire. The smoking manikin was extinguished and then waited for 60 minutes so that the contamination could be evenly distributed in the room.
The air purifier was then activated and the room was cleaned for about 60 minutes at level 7 out of 10.
Immediately after switching on the Dyson Pure Humidify + Cool, the air-Q recorded a sharp drop in particulate matter pollution, which is shown here as an example with the PM₂,₅ values. The level of volatile organic compounds(VOCs) also decreased. Within an hour, the extreme pollution caused by VOCs was reduced to an almost neutral level of 270 ppb (parts per billion). The Dyson air purifier achieved an excellent reduction in particulates from the "fire alarm level" of 220 µg/m³ to "0" within 30 minutes. The same applies to the ultra-fine dust values (PM₀,₅), which were also completely neutralized, albeit with a slight delay.

Here is our particulates extreme test in fast forward:
Conclusion:
Based on its looks alone, the Dyson Pure Humidify + Cool air purifier & humidifier exudes power and technology. The Dyson can keep this promise in the air-Q test for the tested air purification functions. It is able to neutralise even high levels of air impurities quickly and can effectively counteract the continuous pollution (e.g. from open windows, people present as well as chemicals present in furniture) in continuous operation. The Dyson does a good job and reliably filters aerosols and particulates particles out of the air. It can also humidify and cool the air.