CADR Rating 101: Uncovering The Truth In Air Purifiers Selection

When shopping for an air-cleaning device, you may have come across the term CADR (Clean Air Delivery Rate) ratings. Do not ignore it as the key factor in evaluating the right air purifier based on your needs. In this post, we'll explain what CADR ratings are, how they are calculated, why is it important, the "good" numbers, and the limitations so you can make an informed decision when purchasing an air purifier.


What Exactly Are Air Purifiers’ CADR Ratings?

CADR (Clean Air Delivery Rate) ratings measure an air purifier’s effectiveness in removing specific pollutants from the air. It was developed by the Association of Home Appliance Manufacturers (AHAM) to provide a standardized way for consumers to compare the performance of different air purifiers.

Three main types of pollutants are measured: dust, pollen, and smoke in cubic feet per minute (cfm). The higher the CADR rating, the more efficient the air purifier is at capturing airborne pollutants in a minute. For example, a smoke CADR rating of 200 for smoke indicates that the air purifier can effectively remove 100 cubic feet of smoke per minute. Likewise, a dust CADR rating of 200 indicates that the air purifier can remove 200 cubic feet of dust per minute.

Overall, CADR ratings are a valuable metric for comparing and deciding the best air purifier to buy based on your needs.

Limitations: Why CADR Ratings Are Not Perfect

While CADR ratings are widely used by consumers to compare air purifiers’ performance, the result may not paint a full picture. Many experts believe that CADR can be misleading when misinterpreted, particularly for newcomers. There are a couple of downsides to using CADR ratings as air purifiers evaluation:

  1. Fixed room size – CADR tests are conducted in a controlled laboratory setting, typically a room size of around 400 square footage. The outcome may be inaccurate with a different room size or open space area.
  2. Limited measurement – CADR ratings only measure the effectiveness of an air purifier against specific air pollutants of few particle sizes i.e. dust, pollen, and smoke. They do not consider other common indoor pollutants such as chemicals, gases, or odors. As such, an air cleaner with high CADR ratings is not guaranteed to remove all types of air pollutants effectively.
  3. Noise level – CADR ratings do not take into account the noise level of an air purifier. Loud air purifiers are less desirable for bedrooms use or when you need peace of mind.
  4. Filter replacement costs – CADR ratings do not consider the expense of replacing filters, which is vital to an air purifier’s long-term ownership. Some HEPA filter replacements will cost a few hundred dollars annually!
  5. Energy-efficient – Another cost-related factor will not be weighed by CADR. You will need to look into the Energy Start certification yourself.
  6. Ease of use – CADR ratings disregard the air purifier’s design and size; it will impact how practical and usable the air cleaner will be, particularly in tight spaces.
  7. Supporting features – Auto mode, sleep mode, fan speeds, timer, and WiFi enabled are ignored by CADR. It does not paint the full picture of the air purifier value.
  8. Limited to filter-based – CADR ratings are not applicable for all types of air purifiers with a different set of technologies. For example, UV-C air purifiers, which use ultraviolet light to kill germs and bacteria, and ionizers that discharge ions do not have CADR ratings.

Keep in mind that CADR ratings are only one metric used to assess an air purifier’s worth. When purchasing an air cleaner, it is important to consider factors like noise level, filter costs, and design, as highlighted above.

What CADR Rating Do I Need?

The CADR rating varies depending on your specific needs and the types of contaminants you are dealing with. For general use, an air purifier with a CADR rating of at least 100 cfm for smoke, dust, and pollen is sufficient. For people with allergies, asthma, or other health concerns that require consistent good air quality in the home, consider an air purifier with a CADR rating of at least 200 cfm. A CADR 200 is very good at removing 200 cubic feet of airborne pollutants per minute. It will ensure that the air purifier can swiftly remove triggers and reduce allergy symptoms like cough, sinus, headache, sore throat, red eyes, and itchiness.

If you need more time to make up your mind, we recommend consulting with air professional or manufacturers' CS to confirm that the air purifier you choose has the right amount of CADR rating suited for your needs.

How Do I Check CADR Ratings?

Here are a few ways to check the CADR ratings of an air purifier:

  • Look at the product's packaging or manual. The AHAM Verified seal CADR ratings would be listed prominently if available.
  • Visit the manufacturer's website. Most brands will list the CADR rating of their air purifiers under the specification section.
  • Visit the AHAM website. AHAM will regularly maintain and update the database of all verified CADR air purifiers.
  • Check the filter. Some air purifier filters will have CADR ratings printed on the filter packaging or the filter itself.

How To Compare Air Purifiers With CADR

Even though there are limitations to CADR, there is no denying its usefulness. Here are a few tips for comparing air purifiers with CADR ratings:

  • First thing first, look for AHAM Verified Seal. Doing so ensures that the CADR rating of the air purifier is valid and verified by the Association of Home Appliance Manufacturers (AHAM). You will be surprised that are many disingenuous brands out there.
  • Look for CADR ratings for specific pollutants most relevant to your needs. For example, if you have a concern with dust, go with a model that fits the bill.
  • Consider the air purifier placement and use CADR ratings to check the room size compatibility. As CADR is tested in a controlled laboratory setting with high air changes per hour (ACH), you will need an air cleaner that caters to the minimum purifying coverage in the room to be truly effective.
  • Focus on filtration. Air purifier with high CADR ratings is nothing without filters. Look for activated carbon and HEPA filters to help capture fine particles like bacteria and viruses.
  • Compare multiple factors (including non-CADR). As mentioned earlier, CADR is only part of the equation of the overall quality of an air purifier. Consider the usability, build quality, and maintenance before purchasing one.
  • Lastly, go through user reviews and experts to gauge the air purifiers' real-world performance. There might be some critical information that you missed out on.

Take note that not all air purifiers have CADR ratings. It is optional for the manufacturers to participate and provide the numbers. Some models use different technologies to clean the air, so the CADR test is not applicable because it cannot measures the same thing.

What Is AHAM Verified Seal?

The AHAM Verified seal is a certification program created by the Association of Home Appliance Manufacturers (AHAM) to verify the accuracy of air purifiers' Clean Air Delivery Rate (CADR) ratings. It is a good indicator of quality and reliability that can be used to accurately compare information about the performance of different air cleaners. The AHAM Verified seal would only be awarded to air purifiers that have undergone a series of testing in a controlled laboratory and matched the CADR ratings that the manufacturer claims.

What Air Purifier Has The Highest CADR Rating?

There are many air purifiers on the market with high CADR ratings. Here are just a few:

  1. GermGuardian AC9200WCA
  2. Alen BreatheSmart 75i
  3. Medify Air MA-112
  4. Blueair 605
  5. Blueair Pro XL
  6. Gocheer GH-Monster Smart
  7. LEVOIT Core 300

Visit our high CADR air purifier to learn more about these models and which you should pick.

To Recap

  • A standardized test developed by the Association of Home Appliance Manufacturers (AHAM).
  • CADR (Clean Air Delivery Rate) ratings measure the effectiveness of air purifiers in removing specific pollutants from the air.
  • It is calculated in cubic feet per minute (cfm).
  • The CADR system covers three primary pollutants: dust, smoke, and pollen.
  • The goal is to help consumers compare the performance of different air purifiers and make informed purchasing decisions.
  • A higher CADR rating indicates the air purifier is more effective at capturing airborne pollutants.
  • Limited testing on specific pollutants in a controlled environment rather than the overall quality of the air purifier.
  • Noise level, non-filter technology, filter life, and energy efficiency are not take into account.


Max Fernandez

A loving father and a dedicated reviewer for airfuji.com with more than 1000 air purifiers under his belt. Max Fernandez is also one of the million patients currently suffering from asthma. Feel free to nudge him if you have any questions.
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