The CADR Rating – Clean Air Delivery Rate Explained

In this article, we will explain to you what CADR means and what it represents. You’ve probably seen these letters on every home air purifier that you’ve analyzed and you’ve wondered what do they stand for. Well, this term stands for Clean Air Delivery Rate and it’s awarded by the Association of Home Appliance Manufactures. By knowing the Clean Air Delivery Rate, the customers will be able to better evaluate the air cleaners and to choose the one that offers the best performance.

What is the Clean Air Delivery Rate?

The Clean Air Delivery Rate is basically a numerical value that represents the capacity of a filter to remove the pollutants in the air and it’s measured in cubic feet per minute. This test is performed by the Association of Home Appliance Manufacturers (AHAM) and it was established for portable room air purifiers ever since the 1980s. The main purpose was to establish an objective standard for all purifiers, so people can differentiate their air cleaning efficiency.

How Is the Test Performed?

The Clean Air Delivery Rate test is relatively simple and it only lasts 20 minutes, being applied to three of the most common indoor air pollutants: smoke, dust, and pollen. The purifier is placed in a closed chamber of 1008 cubic feet that is filled with a certain amount of each indoor air pollutant, ranging from 0.09 to 11 microns. Meanwhile, a number of pollutants is re-evaluated and the final results represent the volume of air that the purifier is able to clean for each of the three pollutants in cubic feet per minute. The numbers come in a specific order, for smoke, dust and pollen and the higher the number is, the more efficient the air cleaner. Here are the ratings:

– 10 to 450 rating for tobacco smoke
– 10 to 400 rating for dust
– 25 to 400 rating for pollen

How Reliable are the Results?

The process of measuring the efficiency and performance of the air filters is made under strict surveillance and by following the same standards. Therefore, the CADR rating is considered a reliable tool in this industry. However, since the available air purifiers are created using different technologies the CADR rating may vary, thus confusing many customers. The conclusion is that you should always check the numbers because it plays an important role when choosing the right air purifier, but at the same time, you should also take into account the technical specifications and features of each purifier.


  • Julia

    Thank you for the useful article, I never actually understood what that rating stood for until now!

  • Theo

    Buying an air purification system isn’t easy at all as you do need to know what certain specs stand for. Now that I fully understand what the CADR rating actually stands for, it will be a lot easier for me to choose the perfect purification system for home use. Thanks for your help!

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