Are you breathing clean air inside the house? If you’re not sure, then you probably need an air purifier – especially if you have dogs, if you live in a mold-growth prone place, or if your family constantly suffers from runny nose and other types of allergic reactions.

Blueair is one of the most popular names in air purification. In this post, we’re highlighting the Blueair Classic 203, an energy-star rated air purifier that covers up to 240 sq ft of living space. It’s designed for small rooms, and you can easily find a space for it in your bedroom (or your kids’ room).

In this Blueair Classic 203 Slim review, we give you the pros and cons of the product, as well as its key features that you should know before making a purchase.

Key Features of the Classic 203 Slim


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Here’s what to expect.

HEPASilent Technology

How does the HEPASilent Technology work?

In simple terms, this feature combines the power of electrostatic charges and mechanical filtration to capture and eliminate airborne particles. It does everything while using less energy and producing less noise.

Note that the Blueair Classic 203 is equipped with a True HEPA filtration system.

Take a look at the image on the right. It clearly demonstrates how the HEPASilent feature works.


To borrow the words of Blueair, the Classic 203 Slim is a “small purifier” but delivers “big results.” It has a small footprint, which purifies spaces of up to a 240-sq. ft. area.

Aside from that, this air purifier weighs 24 lbs (or 11 kg.). But although it’s lighter than some air purifiers, it may not be easy to move it in case you want to use it in the other room. Why? Because it doesn’t come with casters.

The Blueair 203 Slim comes with a simplified control panel consisting of a mechanical knob that you can simply twist to select the speed of your preference. Note, however, that no matter how simple the controls may be, this air purifier comes with a timer that alerts you when the filter needs to be changed.

Other Features and Technical Specs

  • Weight: 11 kg (24 lb)
  • Product Dimensions: 533 x 432 x 209 mm (21 x 17 x 8 in)
  • Room size: 22 sq. m. (240 sq. ft.)
  • CADR (Smoke): 155 cfm
  • CADR (Dust): 155 cfm
  • CADR (Pollen): 155 cfm
  • Sound level: 32- 56 dB(A)
  • Air outlet: Top
  • Air inlet: Back
  • Wifi enabled, Amazon Alexa compatible

Also read: Austin Air HealthMate HM400 Review: Buy or Forget It?

Consumer Feedback

In this section of our Blueair Classic 203 Slim review, we



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  • Noise. The general consensus is that the Classic 203 Slim is quiet on low, but on the highest setting, there is a noticeable “hum,” “furnace-like sound,” or a “background noise” which you may find annoying if you have a low noise tolerance. Otherwise, you’ll just dismiss it as white noise.
  • Performance. It works, based on general feedback. However, as one person has observed, it might take a few days to notice a difference when you’re purifying a room that has a mixture of stuck-on odors. One person shares that before having the Blueair Classic 203, cigarette smoke from her chain-smoking neighbors used to cause her migraines. But with this air purifier, the migraines stopped.
  • Allergens. Does it help people with allergies? Not everyone agrees, but generally speaking, it does relieve allergy symptoms/reactions. This seems to be a good tool for people who have breathing difficulties because of dust and other types of allergens.


  • It doesn’t come with casters.
  • The blue LED light cannot be turned off. A quick fix is to put a tape on it.
  • Unlike other brands, this air purifier doesn’t have the capacity to monitor the air quality of the room.
  • If you’re looking for an on/off switch for the 203 Slim’s ionizer function, this device, unfortunately, doesn’t come with one.
  • You might find that the replacement filters are pricey.
  • Sometimes, there are issues related to Wifi connection (e.g., connection drops).

Also read: Alen T500 vs Paralda: Which Air Purifier is Better?

Our Recommendation: Blueair Classic 203 Slim Review

Let’s end this Blueair Classic 203 Slim review right. Here’s our final say.

The general consensus is that the Blueair Classic 203 Slim works well in purifying the air, as evident in consumer reports with positive feedback regarding alleviating or eliminating allergic reactions/symptoms. It also sucks out cigarette odors, pet smells, and other airborne particles. Buy the Blueair Classic 203 here.


Check Price » Blueair Classic 203 Slim

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