NADCA Debuts 2021 Edition of ACR Global Standard

The National Air Duct Cleaners Association has updated its Standard for the Assessment, Cleaning, and Restoration of HVAC Systems.

The National Air Duct Cleaners Association (NADCA), also known as the HVAC Inspection, Cleaning, and Restoration Association, has released its 2021 edition of ACR, The NADCA Standard for the assessment, cleaning, and restoration of heating, ventilation, and air conditioning (HVAC) systems. The Standard is available online as a free download.

The 2021 edition of ACR, The NADCA Standard, reflects necessary updates to the Standard after new testing was conducted by EMSL Laboratories. The ACR is an international standard that defines the minimum performance and procedural requirements for air duct cleaning. It includes practical, industry-backed information for assessing new and existing HVAC systems, evaluating and verifying the cleanliness of HVAC system components, preventing job-related hazards such as exposure to workers and occupants and cross-contamination of the indoor environment, and guiding the cleaning and restoration of HVAC systems to a specific level of cleanliness.

The new edition of the ACR has evolved from procedural-based guidelines, standards of care, and research originating from NADCA and associated organizations. It is based on reliable principles, review of applicable industry literature and information, and practical experience.

This document is written for use by anyone involved in the HVAC cleaning and restoration industry including specifiers, consultants, and contractors. Users of the document should stay updated and informed about changes in the industry, and implement changes in technology and procedures, as appropriate, while following applicable federal, state, provincial, and local laws and regulations.

“The ACR is considered the global standard of care for the HVAC cleaning and restoration industry, and it’s available as a free download on our website,” said NADCA Chief Executive Officer, Jodi Araujo, CEM.  “The NADCA Standards Committee has worked diligently to make sure the 2021 edition covers every angle to assist individuals and entities in establishing and maintaining their professional competence while working in the duct cleaning industry. The 2021 edition will be continually reviewed, evaluated, and validated through practical application in the field, and revised as necessary.”

ACR, The NADCA Standard: 2021 Edition, is available for free download here at

ACR the NADCA Standard


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