CADR stands for Clean Air Delivery Rate and indicates how much clean air an air purifier delivers per hour, usually in cubic meters per hour (m³/h). The higher the CADR, the faster the device can filter the air in a room. The figure helps you choose a purifier that suits the size of your space.
What exactly does the CADR value tell you?
The CADR is a measure of purification capacity: the volume of air that the device removes a certain type of particles from per hour, such as dust, pollen, or smoke. An air purifier with a CADR of 260 m³/h can therefore purify 260 cubic meters of air per hour. This is different from the air displacement volume of the fan: the CADR takes the filter into account. A purifier with a lot of airflow but a poor filter will therefore score lower.
CADR and room size: how do you calculate it?
A simple rule of thumb is to divide the volume of the room by the CADR to see how many times per hour the air is theoretically refreshed. A room of 20 m² with a ceiling height of 2.5 meters has 50 m³ of air. With a CADR of 260 m³/h, that is theoretically more than five times per hour. In practice, the values are lower, because air does not circulate equally well everywhere and doors are open. Treat such calculations as a guideline, not a guarantee.
What CADR does not tell you
The CADR says nothing about the filter quality itself and nothing about noise. According to the European standard EN 1822, a HEPA 13 filter captures at least 99.95 percent of the particles in the most penetrating size, but the final performance depends on the airflow, the placement, and how long the device runs. Also read our article about what an air purifier does and does not remove from the air.
An air purifier also does not replace ventilation. The Lung Foundation explains that ventilation is still necessary because an air purifier removes fine dust, but does not exhaust stale air. The RIVM also states that portable air purifiers filter particles, but do not refresh the air. An air purifier is not a treatment for complaints; consult your GP if in doubt. The Lung Foundation also reports that there is no hard evidence that an air purifier leads to better health in the case of lung disease.
Direct answer: CADR is the amount of filtered air per hour; choose a value that suits your room size and continue to ventilate.
Dynter AirPure Plus PA244 in practice
The Dynter AirPure Plus PA244 is an air purifier with a 4-stage filtration system and HEPA 13 filter.
CADR: 260 m³/h
Suitable for: spaces up to 55 m²
Noise: 28-60 dB
Consumption: 45W
Operation: three fan speeds, automatic mode, touch display and sleep mode
Filter: replaceable, 6-8 months of use according to the product page
Comparing CADR: what to look for?
| Feature | Why it matters |
|---|---|
| CADR (m³/h) | Purification capacity per hour |
| Room size | Determines how much capacity you need |
| Noise (dB) | Important for bedroom and office |
| Filter type | HEPA 13 for fine particles |
| Filter costs | See costs of filters and electricity |
View the Dynter AirPure Plus PA244 or the HEPA 13 replacement filter. More air purifiers can be found in the air purifier collection. Placement is also important, read where to best place an air purifier.
Frequently asked questions
Is a higher CADR always better?
Not necessarily. A higher CADR means more capacity, but often also more noise and consumption. Choose a value that suits your room.
Is CADR the same as m² range?
No. The CADR is a purification speed, the m² range is an indication of the room size.
How often does an air purifier refresh the air?
Divide the room volume by the CADR for a theoretical value per hour. In practice, that is lower.
Does an air purifier help with allergies?
It can filter particles such as pollen, but it is not a treatment and does not replace medication or medical advice.
Do I still need to ventilate with an air purifier?
Yes. An air purifier does not exhaust stale air and does not remove CO2.