OTTOwhite 353 €
Deliveryabout 1–4 days
Returns30-day free returns
Clean Air Optima CA-509Pro
Rank 1 of 2 air purifiers for large rooms in our ranking.in our ranking
Score 4.8 out of 10
Owners’ ratings, 40%: none yet at the shops that deliver to Germany, so this part is left out and the score is the features part alone.
Features, 60%: 4.8, 29 of the 60 points for the maker’s and the registers’ facts.
Price does not count, so a discount never lifts a model. Only air purifiers with a known CADR are ranked.
The highest score today is 7.0.
Is the Clean Air Optima CA-509Pro right for your home? Find out in 7 questions →
Before you buy, compare it with 2 recommended alternatives
Beside it, two models on sale today that come closest to it on score and price, for the same room size where we have them.
Green is the best of these 3, also when they share the lead.
| This model Clean Air Optima CA-509Pro | Much better, not dearer Clean Air Optima CA-503 Compact Best on 3 facts | Lower score, 46% cheaper Xiaomi Smart Air Purifier 4 Compact | |
|---|---|---|---|
| Price and ranking | |||
| Lowest price | 353 €OTTO | 132 €OTTO best | 189 €OTTO |
| Score | best | ||
| Rank | rank 1 of 2 for large rooms | rank 1 of 1 for small rooms | rank 2 of 2 for medium rooms |
| Customer rating | – | – | – |
| Room size | |||
| Room size | large roomsup to 90 m² | small roomsup to 30 m² | medium roomsup to 27 m² |
| Size, noise and age | |||
| Height lower is better | 56 cm | 27.4 cm best | 35.5 cm |
| On the market since | – | – | – |
Facts as the maker states them. A dash means the maker does not name it. Each model’s page gives the source of every fact. Noise is the maker’s own figure, so we do not judge it, and a customer rating only counts from 20 reviews.
Prices per shop
On 17 October 2026 the lowest price for the Clean Air Optima CA-509Pro is 353 € at OTTO, delivery to Germany included. In our ranking it is rank 1 of 2 for large rooms, with a score of 4.8 out of 10.
All prices include VAT and delivery to Germany. We may earn a commission when you buy through these links. It never changes our ranking.
OTTOwhite Price history
Lowest price per day
Lowest since 17 Oct353 €
Highest since 17 Oct353 €
Price drops since 17 Oct0no drop seen yet
Clean Air Optima CA-509Pro specifications
The numbers that matter first, then every fact by group. As published by the maker or the shop we read it from.
Clean air delivery rate (CADR)400 m³/h
Room size we compare on33 m²
Filter life6 months
Power at the highest speed53 W
Consumables: The filter lasts about 6 months.
Cleaning performance 4 facts
- Clean air delivery rate (CADR)
How much clean air the purifier delivers an hour, measured with smoke, dust and pollen. A higher figure cleans a bigger room or the same room faster.
- 400 m³/h
- CADR measured to
The test the CADR comes from. AHAM AC-1 and the DOE test are independent and comparable. A maker's own test is not.
- Not stated
- Room size we compare on
The room size where the purifier changes the air 4.8 times an hour under a 2.5 m ceiling, worked out from its CADR. We use it so every model is compared on the same rule.
- 33 m²
- Room size the maker claims
The room size the maker states. Makers use different rules, so we show it but never rank on it.
- 90 m²
Filter 3 facts
- HEPA filter class
How fine the filter is. True HEPA and H13 catch at least 99.97% of particles at 0.3 microns. HEPA-type is a weaker claim with no test behind it.
- True HEPA
- Filter layout
Whether the particle and carbon layers are one filter or separate ones. Separate filters let you replace only the part that is spent.
- One combined filter
- Activated carbon filter
A filter of activated carbon that takes out smells and some gases. It does not catch particles.
- yes
Running costs 1 fact
- Filter life
How long the maker says a filter lasts, in months of normal use. A filter that is spent cleans less.
- 6 months
Noise and power 2 facts
- Noise at the highest speed
The sound level at the highest speed, as the maker measures it.
- 55 dB
- Power at the highest speed
The power the purifier draws at its highest speed.
- 53 W
Air quality sensing 2 facts
- Air quality sensors
What the purifier measures in the air. A particle sensor lets it speed up and slow down by itself.
- PM2.5, Temperature, Humidity
- Automatic mode
The fan speed follows the air quality the sensor reads.
- yes
Smart features and warranty 1 fact
- App control
- Wi-Fi
Build 2 facts
- Height
How tall the purifier is. It decides whether it fits on a shelf or under a window sill.
- 56 cm
- Weight
What the purifier weighs. It counts most if you move it from room to room.
- 7.5 kg
Warranty and certification 2 facts
- Warranty
The warranty the maker gives in Germany. Consumer law here stands apart from it and can last longer.
- 2 years
- Maker model numbers
- CA-509Pro Smart
Sources: Manual
Our score
Confidence: medium. A CADR the maker states itself, or fewer than 300 owners’ ratings. The highest score today is 7.0.
-
Owners’ ratings 40%–
Owners’ ratings, 40%: none yet at the shops that deliver to Germany, so this part is left out and the score is the features part alone.
-
Features 60%4.8
29 of 60 points for the maker’s and the registers’ facts.
- Price never countsA sale can’t lift a model. Today’s lowest price sits beside the score, checked every morning.
- No CADR, no rankOnly air purifiers with a known CADR are ranked. The rest get a provisional score.
- Reviewers beside, not insideReviewers’ picks are shown next to the score and do not count in it.
The maker
Clean Air Optima
- Reviews on Trustpilot
- Headquarters: Netherlands
- Owned by Clean Air Optima International B.V., Netherlands
Clean Air Optima is a brand of Clean Air Optima International B.V., a company registered with the Dutch Chamber of Commerce in the Netherlands. Its range of standalone air treatment appliances includes air purifiers, humidifiers, air washers and dehumidifiers, along with hybrid models that combine humidifying or dehumidifying with air purification.
