CADR Ratings: What You Need to Know

Air quality is a growing concern, especially with increasing pollutants infiltrating our homes and workplaces. Air purifiers are essential for maintaining healthier indoor environments, but how do you determine their efficiency? This is where Clean Air Delivery Rate (CADR) becomes crucial. By understanding CADR ratings, you can choose an air purifier that suits your needs and ensures cleaner, fresher air for you and your loved ones.
What Is a CADR Rating and Why Does It Matter?

CADR, or Clean Air Delivery Rate, is a standardized metric used to measure an air purifier’s efficiency in removing specific airborne pollutants, including smoke, dust, and pollen. This rating indicates how much clean air (measured in cubic feet per minute) the device delivers into a room.
Why does CADR matter? It provides an objective way to compare air purifiers. Instead of relying on marketing claims, you can use CADR values to assess performance. For instance, a purifier with a CADR value of 300 will clean the air more effectively and quickly than one rated at 200.
Moreover, CADR ensures transparency, giving consumers confidence that they’re investing in a product that delivers measurable results for improved indoor air quality.
Breaking Down the Clean Air Delivery Rate (CADR)

The CADR system evaluates a purifier’s ability to remove three common pollutants:
- Smoke: Represents the smallest particles (as small as 0.1 microns) and is the hardest to filter.
- Dust: Medium-sized particles typically found in most homes, ranging from 0.5 to 3 microns.
- Pollen: Larger particles (up to 10 microns) that can trigger allergies.
Each pollutant receives its own CADR score, usually displayed as separate values on the purifier’s label. Higher numbers indicate faster pollutant removal.
For example:
- CADR for Smoke: 200
- CADR for Dust: 250
- CADR for Pollen: 300
These scores allow you to identify which pollutants the purifier is most effective against, ensuring you select the right product based on your environment’s specific challenges.
CADR Ratings and Room Size: Finding the Perfect Fit

An air purifier’s CADR rating is directly linked to the size of the room it can effectively clean. Using a purifier with a low CADR in a large room will result in insufficient filtration, while an overpowered purifier in a small room can waste energy unnecessarily.
How to calculate the ideal CADR for your room:
- Multiply the room’s square footage by 0.75.
- Example: A 200-square-foot room requires a minimum CADR of 150.
This ensures the purifier delivers optimal air cleaning effectiveness for the space it’s used in. Manufacturers often include recommended room sizes on their products, but calculating CADR based on your room’s dimensions provides a more precise measure.
How Are CADR Ratings Tested and Certified?

CADR ratings are rigorously tested by the Association of Home Appliance Manufacturers (AHAM) to ensure reliability and consistency. These tests simulate real-world conditions to measure how effectively purifiers filter pollutants over time.
Factors influencing CADR testing include:
- Fan Speed: Higher fan speeds improve airflow, resulting in higher CADR values.
- HEPA Filters: High-Efficiency Particulate Air (HEPA) filters are critical for trapping fine particles and achieving high CADR scores.
- Room Environment: Tests are conducted under controlled conditions to ensure accurate pollutant measurement.
Look for the AHAM Verified® seal when purchasing air purifiers, as this certification guarantees that the CADR ratings have been independently tested and validated.
Interpreting CADR Ratings for Better Air Purifier Choices

Understanding CADR values helps you make informed decisions about which purifier is right for you. Here’s what to keep in mind:
- Higher CADR Ratings = Faster Filtration: A higher CADR indicates quicker removal of pollutants, but it doesn’t always reflect total air cleaning effectiveness.
- Balanced Scores Across Pollutants: Choose a purifier with consistent CADR ratings for smoke, dust, and pollen to ensure all-around performance.
- Limitations of CADR: CADR doesn’t measure a purifier’s ability to remove odors or gases, which may require additional features like activated carbon filters.
By considering these aspects, you can avoid being misled by inflated claims and focus on actual performance metrics.
Factors That Impact CADR Ratings

Several factors can influence an air purifier’s CADR rating:
- Pollutant Type: Smoke particles are smaller and harder to filter, resulting in lower CADR scores compared to larger particles like pollen.
- Fan Speed: Increasing the fan speed boosts airflow, improving the purifier’s ability to filter air quickly. However, it may also increase noise levels.
- Filter Quality: The type and quality of filters, such as HEPA or activated carbon, significantly affect the purifier’s overall efficiency.
Understanding these factors ensures you evaluate CADR ratings within the context of real-world usage, avoiding over-reliance on a single metric.
Beyond CADR: Considering Other Air Purifier Features

While CADR is essential, it’s not the only factor to consider when choosing an air purifier. Other critical features include:
- HEPA Filters: Essential for trapping microscopic particles like allergens and fine dust.
- Activated Carbon Filters: Effective for absorbing odors and harmful gases, which aren’t reflected in CADR ratings.
- Noise Levels: Quiet models are ideal for bedrooms or offices, where excessive noise can disrupt daily activities.
- Energy Efficiency: Look for purifiers with energy-saving modes to reduce long-term operating costs.
These features complement CADR ratings, ensuring you get a device that meets all your air purification needs.
Choosing the Right Air Purifier for Your Needs

Follow these steps to select an air purifier that delivers the best results:
- Assess Your Room Size: Use the CADR formula (room size × 0.75) to determine the required rating.
- Identify Pollutants in Your Space: Focus on CADR scores for the pollutants most prevalent in your environment.
- Evaluate Additional Features: Consider features like HEPA filters, activated carbon, and energy efficiency.
- Buy Certified Models: Always choose purifiers with the AHAM Verified® seal to ensure accurate CADR ratings and performance claims.
Taking these steps guarantees you’ll find a purifier that aligns with your needs, improving both your health and overall comfort.
FAQs About CADR Ratings and Air Purifiers
Q: Can CADR ratings be trusted?
Yes, provided they’re certified by AHAM. This ensures the purifier has been independently tested for performance.
Q: Are higher CADR ratings always better?
Not necessarily. The right CADR depends on your room size and specific needs.
Q: What’s the difference between CADR and ACH (Air Changes Per Hour)?
CADR measures pollutant removal speed, while ACH indicates how many times the purifier circulates air in an hour.
Conclusion: CADR Ratings and Cleaner Air
By understanding CADR ratings, you unlock the key to selecting air purifiers that deliver cleaner, healthier air tailored to your needs. From matching CADR to room size to evaluating additional features, this knowledge empowers you to make informed decisions that improve your indoor environment.
Take action today by exploring certified air purifiers with reliable CADR ratings. Your health and comfort deserve the best—don’t settle for less when it comes to the air you breathe.