For years I have been quoted as saying that the hvac hygiene remediation (also known as air duct cleaning) industry is akin to the wild, wild west.

Even with the advancement of inspection and cleaning technologies in the past several years, the comparison to the “outlaw days” may even be truer now.

While once considered unnecessary by some “industry experts,” hvac hygiene is presently recognized as a key component of maintaining acceptable indoor environments. Remediation services are being increasingly sought after by consumers at every level.

This potential boom market creates several dilemmas for all parties involved. Consumers (both commercial and residential) are beginning to realize the need for maintaining good hygiene in hvac systems, but they are lacking some vital direction in deciding when and how to clean or remediate their systems.

Often, a perceived IAQ problem in a building will spur management to have the hvac ductwork cleaned, to rid them of their “IAQ problem.”

Open any phone book in America, and you’ll have little trouble finding some service company to rid you of greenbacks, often without any consideration of the perceived or actual IAQ problem. And certifications, trade association memberships, and other purported credentials are only as good as the people holding them — such credentials are by no means a guarantee of quality work.

Not all potential service providers are incompetent or scam artists. To the contrary, there are many highly qualified professionals in the remediation industry who can provide valuable services to their clients.

The real problem is that most consumers do not have the expertise or the information to make informed buying decisions for these services. This lack of “buyer’s knowledge” opens the door for unscrupulous vendors to provide inferior or unnecessary services.

Low cost, low quality

Add a lack of good project design and specifications and a competitive bidding environment to the mix, and the client can pretty much count on getting burned.

IAQ remediation is inherently not “apples-to-apples,” and lowest price often equates to lowest quality service.

As we approach the year 2000, understanding how to manage hvac hygiene will become increasingly important, and equally difficult.

If an end-user or third-party specifier doesn’t have actual first-hand remediation experience, there currently isn’t a single authoritative guide to turn to — no end-all black book to reference!

As a result, quality-oriented service providers lose work, project designers-specifiers look incompetent, and the clients don’t get what they think they paid for. How can the IAQ industry solve this dilemma?

To quote (and twist) a popular political phrase, “It’s the specifications, stupid!” Or, to be more accurate, the key to hvac hygiene is knowledge.

The National Air Duct Cleaners Association (NADCA) has been devoted to building the industry knowledge base over the past decade. Currently NADCA has an array of technical documents that address various aspects of performing hvac hygiene services, which include:

  • “1992-01 Mechanical Cleaning of Non-Porous Air Conveyance System Components” (Standard);

  • “05-1997 Requirements for the Installation of Service Openings in HVAC Systems” (Standard);

  • “Understanding Microbial Contamination in HVAC Systems” (Guideline);

  • “Introduction to HVAC System Cleaning Services” (Guideline); and

  • “General Specifications for the Cleaning of Commercial Heating, Ventilating and Air Conditioning Systems.”

A single standard

In 1998, the NADCA board approved the merger of the PC-01 Revision Committee (01R) and PC-02 (Porous Components Cleaning Standard Committee) due to the logical notion that end-users and specifiers would need the information from each of the documents on a typical project, as well as the obvious overlap between the two documents.

It was decided collectively that a single document would better serve our members and end-users. Such a document would also bear more weight in the IAQ industry.

It is this same logic that led the NADCA Standards Council to create the concept of an “all-inclusive” desk reference document for hvac hygiene services: “Assessment, Cleaning and Restoration of HVAC Systems for Hygiene and Performance” or “ACR-2000” for short.

NADCA already had many of the pieces in the aforementioned documents, but as individual standards and guides (authored over a 7-year period), they are inherently fragmented and sometimes inconsistent.

In addition, an end-user would have to reference five-plus NADCA documents to design a typical commercial project. By merging their efforts and documents, NADCA has created a document that will gain wider acceptance, and have a significant impact on the IAQ remediation industry worldwide.

The purpose of this standard is, “To provide the public and the industry with proper standards and methodologies for the assessment, cleaning, and restoration of hvac systems, including indoor environmental management controls for these processes.”

ACR-2000 will be an international standard providing requirements, criteria, and guidance for:

  • Hvac system hygiene assessment;

  • Project design and specification development for hvac system cleaning-restoration;

  • Cleaning, restoration, installation, service, and/or replacement of the various components of commercial and residential hvac systems;

  • Project monitoring;

  • Verification of hvac hygiene and restoration services; and

  • Proactive hvac hygiene maintenance.

The format is a two-part document that will be offered in both printed and CD-ROM media, which incorporate performance standards and procedural guidance for project assessment, design, and implementation.

The final document will combine NADCA’s 1992-01 (cleaning both porous and non-porous) and 1997-05 (access) in the standards section. A newly updated version of “Introduction to Hvac System Cleaning Services” and the “NADCA General Specification” will be included in the guidance section of the document, along with expanded information on properly assessing hvac system hygiene and remediation project design.

A draft version will be released for public review in late summer of 1999, and will be available for downloading from NADCA’s website at www., or by calling headquarters at 202-727-2926.

Sidebar: AQS unveils its newest environmental test chamber

ATLANTA — Air Quality Sciences Inc. announced that it has finished construction and validation of its third large environmental chamber for testing chemical emissions for indoor products.

These chambers measure trace levels of pollutants including volatile organic compounds, particles, formaldehyde, and ozone as they are emitted from products.

Computer models developed by AQS use the emissions data to evaluate risks imposed by emissions from products in commercial and residential environments, the company says.

The latest large chamber is constructed of a polished stainless steel and is designed to offer a chemically pure, yet realistic, environment with airflow patterns and environmental conditions as would be experienced in a real indoor environment.

For more information on environmental chamber testing, contact Marilyn Black or Tony Worthan at 770-933-0638.