The term "air purifier" sounds broad, but what exactly does such a device remove from the air? The answer depends on the type of filter, but with a good HEPA device, it concerns a wide range of particles, from coarse dust to microscopic virus particles.
Particulate matter (PM2.5 and PM10)
Particulate matter consists of tiny particles originating from traffic, industry, cooking, and even candles. PM2.5 (particles smaller than 2.5 micrometers) is small enough to penetrate deep into the lungs. A HEPA filter is specifically designed to trap these types of small particles very effectively.
Pollen and allergens
Pollen from trees, grass, and herbs are relatively large (10 to 100 micrometers) and are therefore easily stopped by a HEPA filter. The same applies to house dust mite residues and pet dander, common causes of indoor allergies.
Bacteria, viruses, and mold spores
Bacteria and many virus particles are extremely small, often smaller than 0.3 micrometers. A HEPA13 filter is tested at precisely this most difficult particle size (0.3 microns is considered the most difficult size to capture) and traps at least 99.95 percent of them. Mold spores, which are larger, are captured even more effectively.
Odors and volatile compounds (VOCs)
A HEPA filter alone does not capture odors; an activated carbon filter is required for that. Activated carbon binds volatile organic compounds (VOCs) such as cooking smells, cigarette smoke, and fumes from paint or new furniture. Devices with a multi-stage filter therefore often combine a pre-filter, HEPA filter, and carbon filter in one.
Smoke and combustion particles
Smoke, whether from tobacco, a fireplace, or smoke from (wild)fires further away, consists of a mixture of fine particles and gases. The particle fraction is captured by a HEPA filter, while an activated carbon filter absorbs some of the associated odors and gases. This does not always make a room completely odorless, but the particle concentration does measurably decrease.
Microplastics
A lesser-known but increasingly mentioned point: microplastics have also been found in indoor air, originating from, for example, synthetic textiles and the wear and tear of plastic objects. A fine-mesh HEPA filter also captures some of these particles.
Particle size in perspective
To give an idea: a human hair is on average about 50 to 70 micrometers thick. Pollen and house dust mite residues are therefore just barely, but nearly, perceptible to the naked eye. Particulate matter (PM2.5) and virus particles are hundreds of times smaller and completely invisible, which explains why you usually cannot smell or see polluted indoor air, even though the particles are certainly there.
What an air purifier does not do
Important to know: an air purifier does not add oxygen, does not lower CO2 levels, and does not refresh the air with outdoor air. For the latter, ventilation remains necessary. An air purifier only filters the air already present in the room.
Specifically: what does the PA244 filter?
The Dynter AirPure Plus PA244 works with a 4-stage filtration system and a HEPA13 filter that, according to specifications, filters 99.97 percent of particulate matter, pollen, bacteria, viruses, and microplastics from the air. With a CADR of 260 m3/h and suitability for up to 55 m2, it is designed to do this continuously in an average living room or bedroom.
Our advice when choosing an air purifier is to check which particle sizes are explicitly mentioned (particulate matter, pollen, bacteria, viruses), rather than relying solely on the term "HEPA" without a class designation. View the specifications of the AirPure Plus PA244 for a concrete example.