An air purifier filters the air already in your room, while a ventilation system extracts stale air and supplies fresh outdoor air. The difference between an air purifier and a ventilation system is therefore that one removes particles and the other provides air renewal. They do not replace each other: an air purifier does not lower CO2 levels and ventilation does not filter out particulate matter.
What does an air purifier do?
An air purifier draws in room air, passes it through one or more filters, and blows the filtered air back out. With a HEPA filter, you remove particulate matter, dust, pollen, and pet dander from the air. It remains the same air circulating: nothing is added from outside, and gases such as CO2 are not captured. Furthermore, the effect depends on the capacity of the device relative to the size of the room.
What does a ventilation system do?
Ventilation refreshes the air in the house. This can be done naturally, via ventilation grilles and windows, or mechanically, using extraction or balanced ventilation. Ventilation removes CO2, moisture, and cooking odors and brings in fresh air. The RIVM explains on rivm.nl/hygiene/ventilatie why good ventilation is important for a healthy indoor environment. A disadvantage is that outside air can also contain particles, such as pollen or particulate matter from traffic, and these are then brought inside.
Air purifier or ventilation system: the differences at a glance
| Feature | Air purifier | Ventilation system |
|---|---|---|
| What does it do? | Filters particles out of room air | Replaces indoor air with outdoor air |
| Lowers CO2 | No | Yes |
| Removes moisture | No | Yes |
| Removes particulate matter and pollen from the air | Yes, depending on the filter | Not targeted; outside air can actually bring in particles |
| Works with closed windows | Yes | Part of ventilation, also when closed |
When do you need which?
Do you suffer from a stuffy room, fogged-up windows, or a musty smell? Then you solve that with ventilation, because that is about fresh air and moisture. Do you want to reduce the levels of particulate matter, house dust, or pollen indoors, for example because you live on a busy road or have a pet? Then an air purifier can be useful. In practice, it is best to use them alongside each other: first ensure basic ventilation, then filter if necessary. You can read about how to limit particulate matter when cooking in How do you limit particulate matter while cooking?.
Direct answer: an air purifier filters particles out of the air in the room; a ventilation system extracts moisture, CO2, and used air and brings in fresh air. You sometimes need both, because they solve different problems.
Featured: the AirPure Plus PA244 air purifier
The Dynter PA244 is an air purifier with a four-stage filtration system for living spaces up to 55 m².
Filtration: HEPA filter that, according to the specifications, captures 99.97% of particles down to 0.3 micrometers, such as pollen, dust, bacteria, viruses, and microplastics
CADR: 260 m³/h
Suitable for: rooms up to 55 m²
Noise: 28 to 60 dB
Power: 45 W
Operation: touch display, three fan speeds and an automatic mode, plus a sleep mode with dimmed lighting
Dimensions and weight: 25 × 25 × 36 cm, 4.5 kg
Filter: replaceable, after approximately 6 to 8 months
Please note that these are figures from controlled conditions. In a real home, the results depend on the size of the room, how often doors are left open, and how often you replace the filter. An air purifier is also not a medical device and does not replace advice from your GP for complaints such as allergies or asthma. For vulnerable residents, you can read more in Improving the indoor climate for the elderly and vulnerable residents.
Do you want to try it yourself? Take a look at the Dynter AirPure Plus PA244, the matching HEPA 13 filter, or the entire collection of air purifiers. You can read more about the difference compared to moisture control in Air purifier versus dehumidifier.
Frequently asked questions
Can an air purifier replace ventilation?
No. An air purifier does not lower CO2 levels and does not extract moisture. Therefore, continue to ventilate as well.
Does ventilation remove particulate matter from the house?
Not in a targeted way. Ventilation dilutes the indoor air with outdoor air. If the outside air is polluted, that particulate matter also comes inside.
Can you use an air purifier and ventilation at the same time?
Yes, that is actually a good combination. Ventilation provides fresh air, and the air purifier filters particles that enter from inside or outside.
Does Dynter also sell ventilation systems?
No. Dynter offers air purifiers, dehumidifiers, fans, air coolers, and heaters, not mechanical ventilation.
When should I replace the filter of an air purifier?
For the PA244, a replacement interval of approximately 6 to 8 months is indicated on the product page. In practice, the level of air pollution determines how quickly the filter becomes clogged.