Many commercial facilities now consider indoor air quality a crucial factor for growth, sustainability, employee well-being, and overall health. It has transitioned from being an additional value to a requirement in both residential and commercial facilities. Moreover, heightened awareness of airborne contaminants, bacteria, pathogens, and allergens has urged building managers to seek reliable air purification performance metrics. The most significant among these metrics is CADR (Clean Air Delivery Rate).
CADR is an important factor to consider when purchasing air purification solutions. In this blog post, we will explore CADR, Clean Air Delivery Rate, and discuss its role in improving indoor air quality.
Understanding CADR: What is Clean Air Delivery Rate
CADR is a standardised metric used to measure the performance of air purifiers. It measures the amount of air a system filters and delivers per minute. The standard measuring unit of CADR is cubic feet per minute (CFM). The higher the CADR, the more effective and efficient a filtration system is at capturing dust, pollen, airborne pollutants, allergens, and pet dander.
There are three common pollutant categories that CADR ratings measure: pollen, dust, and smoke. Their size ranges are 5–11 microns, 0.5–3 microns, and 0.09–1.0 microns, respectively.
How to Calculate CADR?
The calculation is conducted in a controlled test chamber. Filter efficiency and airflow are the two factors that affect the CADR rating of the tested system. In simpler terms, the formula is:
CADR = airflow × filtration efficiency
The calculation involves measuring how quickly the system removes particles compared to how quickly particles would naturally drop and settle on surfaces. The outcome is then multiplied by the test chamber’s volume. If the chamber is too small and does not represent real-life room sizes, the outcome won’t be applied to real-life scenarios.
Why CADR Matters for Modern Facilities
Faster Pollutant Removal
An air purification system with a high CADR rating enables faster removal of airborne pollutants, dust, mould spores, and smoke. This is essential in high-occupancy indoor spaces where pollutant levels are higher, such as retail stores, healthcare facilities, gyms, and shopping malls.
Improved Overall Health
Indoor environments with poor air quality negatively affect health and well-being. Exposure to airborne contaminants, bacteria, mould spores, and allergens can lead to respiratory issues, fatigue, and lung problems. An air purifier with a higher CADR rating captures these contaminants and reduces exposure, supporting healthier indoor environments.
Ideal Performance in Large Environments
Large commercial facilities require a unit with an adequate CADR rating to help purify indoor air efficiently. Building managers can select an air purification system based on room size and CADR rating to ensure effective performance in large and complex environments.
What Is A Good CADR Rating?
According to AHAM air filtration standards, the CADR (Clean Air Delivery Rate) of an air purification system should be at least two-thirds of the room size. For example, if a room is 120 square feet, you need an air purifier with a smoke CADR rating of 80. Similarly, if a room is 240 square feet, it requires an air purifier with a CADR rating of 160.
Moreover, when selecting an air purifier, you should consider the relationship between CADR and room size. There should be sufficient air exchanges per hour to ensure the space remains fresh and free from pollutants. For commercial facilities, 4–6 air changes per hour are recommended. CADR makes it easier to determine whether an air purification system can achieve the required ACH and operate efficiently.
Evaluating Air Purifiers Using CADR
Review the following checklist before purchasing an air purification system:
Verify AHAM-tested CADR: It is better to verify this rather than relying solely on manufacturer claims.
Match CADR to your room size: Calculate the size of your room and determine the required air changes per hour. The general rule states that 4–6 air changes per hour are required for offices and classrooms, while 6–8 air changes per hour are recommended for healthcare facilities and high-occupancy spaces.
Review CADR for all three pollutant categories: As mentioned, there are three pollutant size categories—pollen, smoke, and dust. Check the CADR ratings for all three, and avoid systems that deliver a high rating in only one category.
Check both CADR and airflow: Cross-check the Clean Air Delivery Rate against airflow, as higher airflow with low filtration efficiency will not deliver effective results. Ensure the system specifies actual filtration efficiency rather than fan power alone.
Ensure filter type and efficiency: Confirm whether the system you are considering features a HEPA filter for higher filtration efficiency.
Euromate Pure Air and CADR
Euromate Pure Air offers a range of advanced air purification systems for residential and commercial facilities. Our air purifiers deliver high Clean Air Delivery Rates and up to 99.95% filtration efficiency. We provide dedicated air purification solutions for both residential and commercial environments, delivering 4–6 air changes per hour (ACH). To learn more about our products and testing standards, please get in touch with us via our contact number.
