Clean Air Delivery Rate


The ongoing pandemic introduced the general public to many new terms and acronyms. While a term such as indoor air quality (IAQ) isn’t new, many more people became familiar with it as a result of COVID-19. HEPA is another term now gaining a wider understanding. It relates to the effectiveness of air filters. CADR, which stands for Clean Air Delivery Rate, is also a term now entering the public consciousness. It’s an important part of air purifier performance, yet many home and business owners don’t fully understand what it is.

Clean Air Delivery Rate Explained   

CADR is a standard set by the independent Association of Home Appliance Manufacturers (AHAM). The rating is certified and verified by an independent laboratory and provides assurances to consumers that a particular air cleaning device works as promised. To put it in simple terms, CADR is a measure of an air purifier’s effectiveness to clean the air based on room size and the volume of air that passes through it measured in cubic feet per minute (CFM).

The efficacy of room-air purifiers depends on the clean air delivery rate relative to the room volume. However, the airflow pattern in a specific room is also a factor. All of these things determine the ability of an air purifier to process air. Therefore, you must use the right devices for a given room.

Portable Room Air-cleaners and Clean-air Delivery Rate 

Many air purifiers use a high-efficiency HEPA air filter that traps up to 99.97% of particulates. This prevents particles such as dust, pollen, and viruses, such as SARS-CoV-2, from recirculating. Even with this filter, the clean air delivery rate is an important consideration as it shows how many air changes per hour (ACH) the device delivers. As an example, providing three ACHs to a room of 1,000 square feet and 8,000 cubic feet, requires a device with a clean air delivery rate of 400 CFM. It is also believed that the higher the CADR, the lower the risk of virus transmission.

Clean Air Delivery Rate and ASHRAE

The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) recognizes the reliability of the clean air delivery rate in determining the effectiveness of air cleaners. As well, the United States Environmental Protection Agency (EPA) also sees the rating as a reliable way for both business owners and homeowners to determine the efficiency of air purifiers. That said, it’s important to note that this rating is intended for portable air cleaners and not HVAC systems. In fact, portable air-cleaning devices, such as the AeraMax Pro AM III, treat the air within a space, while HVAC systems treat the airflow of an entire building. This makes them effective in removing contaminants from specific rooms. Since viruses and other pathogens remain airborne for extended periods, an air cleaner with a high CADR is an effective tool for reducing their spread. 

Building Sciences

Purifiers and their respective clean air delivery rates are important to the health and safety of building occupants. However, it’s not where IAQ ends. Pure Air Control Services has decades’ worth of experience and data that help facilities managers and business owners protect their workers and customers. We assist schools with creating healthy IAQ for students too. We do this through our Building Sciences and Environmental Diagnostics Laboratory. 

Through testing, analysis, and inspections, we determine the contaminant source and provide risk assessments as well as remediation. We do this with the following services and methods:

Building Health Check

The Building Health Check is our in-depth analysis of environmental conditions including clean air delivery rates. It requires logging wall and floor moisture as well as temperature and humidity levels. 

HVAC Hygiene Assessment

Our HVAC Hygiene Assessment measures the building system’s impact on IAQ. The resulting report provides building managers with the information needed to make improvements to the HVAC system.

IAQ Guard

Another important part of creating safe IAQ for building occupants is monitoring. With a single all-in-one module, our IAQ Guard system monitors building conditions around the clock while a remote team tracks environmental conditions in real-time. Changes to building conditions trigger an alert to facilities managers. This allows them to be proactive in dealing with any threats to IAQ.

Clean Air Delivery Rate

Pure Air Control Services works with schools, universities, medical facilities, and commercial businesses across all industries. We help them create healthy indoor environments through inspections, testing, remediation, and the use of air cleaning technology with the right clean air delivery rate. To learn more, contact us at 1-800-422-7873 or email us here.