Numerous Benefits Blow Through Clean HVAC Systems

In order to maintain acceptable indoor air quality levels, it is commonly recommended that mold, fungi, dust and other contaminants be cleaned out of the heating, ventilation and air-conditioning (HVAC) system. Cleaning HVAC systems provides many benefits. It lessens the likelihood of indoor air pollution in the building and may help to alleviate health and comfort complaints by occupants. In addition, clean HVAC systems can save customers money as they perform more efficiently, decreasing energy costs, and, most important, well-maintained mechanical components are more likely to last longer, reducing the need for costly HVAC system replacement or repairs.

Prior to the start of any cleaning, however, a thorough inspection of the system should be performed by a properly trained and certified HVAC inspector. This inspection will determine if a system needs cleaning and, if so, it will help to pinpoint what areas need particular attention. An inspection can also alert facilities managers to physical degradation of key HVAC system components and, the information gained can allow a facility manager to establish benchmarks that illustrate the HVAC system’s cleanliness and how it has been maintained.

What is the best way to clean a system?
If it is determined that the system needs cleaning, a specification should be drawn up detailing the work that is to be performed and the methods by which it will be completed. Until 1989, there were no industry guidelines setting forth the most effective methods for cleaning, but that changed with the formation of the National Air Duct Cleaners Association (NADCA). The organization creates standards and guidelines, but does not endorse or recommend any single method of cleaning or type of equipment. Rather, NADCA recommends the use of source-removal methods and equipment designed to clean HVAC systems according to Standard ACR 2002.

One factor that often dictates the type of cleaning methods to employ is the region or climate in which the project occurs. Regions with high humidity levels often see greater levels of microbial contamination, which can require more aggressive cleaning techniques.

Another factor is the type of ductwork found within the system. Less abrasive techniques such as contact vacuuming are used on fiberglass-lined or flexible ductwork, while air whips and brushes are generally used on standard, sheet-metal ductwork.

Selecting the HVAC cleaning method to be employed on any given project is an important factor toward the successful completion of the job. In some cases, customers may wish to specify the use of specific methods and/or equipment. However, it is often better for the contractor — an expert in HVAC cleaning — to choose the methods and equipment. The customers can negotiate an expected level of cleaning as well as a verification method.

Regardless of what cleaning methods or equipment are used, there is no guarantee or proof of success without some form of cleanliness verification. NADCA Standard ACR 2002 defines three separate cleanliness verification methods: Visual Inspection, Surface Comparison Testing and the NADCA Vacuum Test. At least one of these methods can be incorporated into any project specification.

Rick Crickenberger is president of the National Air Duct Cleaners Association. His company, Dusty Ducts, has been a member of the association since 1991.