What exactly does an air purifier do and do you really need one?

What exactly does an air purifier do and do you really need one? An air purifier draws in indoor air, filters it through a series of filters—including a HEPA filter—and blows clean air back into the room. The device captures fine dust, pollen, dust mites, mold spores, and bacteria before you inhale them. Whether you really need one depends on your situation: people with allergies, asthma, or pets benefit the most, but even in cities with high air pollution, an air purifier at home makes a noticeable difference. Quick answer: An air purifier filters harmful particles such as fine dust (PM2.5 and PM10), pollen, dust mites, mold spores, and bacteria from indoor air. A model with a HEPA 13 filter removes up to 99.97% of particles larger than 0.3 microns. For people with allergies or respiratory complaints, an air purifier is definitely useful; for healthy people in a well-ventilated home, it is a quality improvement that you will notice, but not an absolute necessity. How does an air purifier work on the inside? Most air purifiers work with a multi-stage filter system. First, the air passes through a pre-filter that captures large particles such as hair, house dust, and lint. This is followed by the heart of the device: the HEPA filter (High Efficiency Particulate Air). This ultra-fine filter consists of millions of randomly woven glass fibers that mechanically trap even microscopically small particles. Finally, there is often an activated carbon filter that absorbs odors, volatile organic compounds (VOCs), and gases—think of cigarette smoke, cooking odors, or mold smells. Some models also feature a UV-C lamp or ionizer. These technologies kill bacteria and viruses, but are an addition to—not a replacement for—the HEPA filter. A good HEPA filter is and remains the foundation. What exactly does an air purifier filter? Indoor air is often dirtier than outdoor air, precisely because particles continue to circulate in an enclosed space. An air purifier tackles the following pollutants: Pollutant Size (microns) HEPA 13 effective? Fine dust PM2.5 ≤ 2.5 µm Yes (≥ 99.97%) Dust mites (feces) 1–10 µm Yes Pollen 10–100 µm Yes Mold spores 2–20 µm Yes Bacteria 1–10 µm Yes Viruses 0.004–0.1 µm Partially (UV-C addition recommended) Odors and VOCs Gaseous Only with activated carbon filter Cigarette smoke 0.1–1 µm Yes (combination HEPA + carbon) When is an air purifier really useful? Not everyone benefits from an air purifier to the same extent. The added value is greatest if you are in one or more of the following situations. Allergy or asthma. Pollen, dust mites, and mold spores are the most common indoor allergens. An air purifier significantly reduces the concentration of these particles, noticeably decreasing symptoms such as sneezing, a runny nose, and shortness of breath—especially in the bedroom, where you spend eight hours a night breathing. Pets. Cat hair and dog hair are visibly annoying, but the real culprit for pet allergies is dander. These microscopic particles float in the air for hours and are effectively captured by a HEPA filter. Living near busy roads or industrial areas. Fine dust (PM2.5) penetrates deep into the lungs and is linked to heart and lung diseases. In urban environments, indoor concentrations—even with windows closed—can be surprisingly high. Newborns, young children, and the elderly. Their airways are more sensitive to pollution. Cleaner indoor air contributes to healthier development and a better night's sleep. What are the benefits of a HEPA 13 filter? There is confusion about the different HEPA classes. HEPA 10 filters about 85% of particles ≥ 0.3 µm. HEPA 12 reaches 99.5%. But HEPA 13—the European standard also known as "True HEPA"—removes 99.97% of all particles ≥ 0.3 µm. That sounds like a small difference, but in the presence of high pollen concentrations or fine dust, it means thousands of particles fewer per cubic meter of air per hour. An additional advantage is its service life: with normal use, you only need to replace a HEPA 13 filter once or twice a year. Be sure to check the pre-filter regularly—this significantly extends the lifespan of the more expensive HEPA filter. How many square meters can an air purifier clean? Every air purifier has a so-called CADR value (Clean Air Delivery Rate) and a recommended room area. As a rule of thumb: choose a model that refreshes the air in the room at least five times per hour. For a bedroom of 15–20 m², you need less power than for an open-plan living/kitchen area of 40 m². When in doubt, it is better to choose one size larger—you can then run the device on a lower, quieter setting and still achieve the same air quality. Choosing and ordering the right air purifier The Dynter AirPure Plus PA244 is a quiet air purifier with a certified HEPA 13 filter and integrated activated carbon filter. The device is suitable for rooms up to 40 m² and features an automatic air quality sensor that adjusts the fan speed to the current air quality. Thanks to sleep mode, it runs whisper-quiet at night—ideal for the bedroom. Don't forget to replace the filter in time for optimal performance: the matching HEPA 13 Replacement Filter is available separately in the Dynter webshop. View the full range in the air purifier collection and find the model that fits your space. Frequently asked questions What is the difference between an air purifier and an air cleaner? There is no functional difference: both terms are used for the same device. In the Netherlands, "luchtreiniger" is used most often, while "luchtzuiveraar" and "air purifier" are also common. They all describe a device that filters indoor air via a HEPA filter and/or carbon filter. How much power does an air purifier consume per day? Most household air purifiers consume between 15 and 60 watts on an average setting. With 8 hours of use per day and an electricity price of €0.30/kWh, that costs between €0.04 and €0.15 per day—less than a euro per week. Should an air purifier always be on? For the best results, continuous use is recommended, especially for allergies. In practice, you can set the device to sleep mode or automatic mode at night so that it adjusts itself to the air quality without disturbing you. Is an air purifier harmful to healthy people? No. An air purifier with a HEPA and carbon filter does not produce harmful byproducts. Be careful with ionizers: some models produce small amounts of ozone as a byproduct. When in doubt, choose a model without an ionizer or check if the ozone level remains below safe limits. How often should I replace the HEPA filter? Most HEPA filters last 6 to 12 months with normal use. Check the pre-filter every 4–6 weeks and vacuum or rinse it off. A declining air quality reading or a signal light on the device are signs that it is time for a new filter. Does an air purifier also help against odors? Only if the device has an activated carbon filter. A pure HEPA filter removes particles but not gaseous odors. For cooking smells, tobacco smoke, or damp cellar air, you therefore need a combination filter—or a separate carbon filter in the device.