The HVAC Factor: Standard Maintenance

By Richard Lantz, ASCS, CVI
From the January/February 2014 issue of Today’s Facility Manager

In 2013, a revised ACR, the Standard for Assessment, Cleaning, and Restoration of HVAC Systems from NADCA (National Air Duct Cleaners Association) was released to the industry. This standard has evolved from procedural based guidelines, standards of care, and research originating from NADCA, along with associated organizations. It is based on reliable principles, review of applicable industry literature and information, and practical experience. It focuses on preventing job related hazards, such as exposure to workers and occupants, as well as cross-contamination to the indoor environment. The ACR Standard is a performance standard that also provides facility managers (fms) the minimum air conveyance system cleaning procedural requirements.

The newly revised ACR 2013 delivers a condensed procedural document that can be referenced by fms during an HVAC restoration project. The text has been formatted in a clear and concise manner and has been realigned to follow the flow of an actual HVAC assessment, cleaning, and restoration job. This provides fms the opportunity to locate the information they need quickly and easily.

Why should fms have their HVAC systems cleaned? The short answer is simple: because these get dirty over time, which negatively affects performance and have the potential to contain large amounts of potentially hazardous dust and particulates. A building’s air conveyance system acts as its respiratory system. Dirt, dust, debris, and microbial growth that accumulate inside of air ducts, on cooling coils, and on reheat coils are “out of sight”, hence “out of mind” and can “congest” the air conveyance system. This makes it difficult for the building to “breathe” properly and function efficiently.

According to the U.S. Department of Energy, 25% to 40% of the energy used for heating or cooling is wasted. Contaminants in a heating and cooling system cause it to work harder and shorten the life of the system. Although filters are used, the heating and cooling system still gets dirty through normal use. When an HVAC system is clean, it doesn’t have to work as hard to maintain the desired temperature.

Proper cleaning of the cooling coils and reheat coils alone can increase airflow by as much as 75%. An ASHRAE study concluded that maintaining HVAC system cleanliness could reduce average operating expenses by 10% to 25%. With energy costs rising every year, it is more important than ever for fms to ensure HVAC equipment is maintained and operating at peak efficiency.

Through normal occupation in a building, users generate a great deal of contaminants and air pollutants, such as dust, dander, and chemicals. These contaminants are pulled into the HVAC system and recirculated five to seven times per day, on average. Over time, this recirculation causes a buildup of contaminants in the ductwork. While a contaminated HVAC system doesn’t necessarily mean unhealthy air, the situation may be contributing to larger health issues or harboring contaminants that could cause serious problems for people with respiratory health conditions, autoimmune disorders, or some environmental allergies.

Often HVAC system components collect significant amounts of debris and particulate during construction activities or remodeling within a facility. NADCA recommends that newly installed systems or those undergoing renovation be protected and verified clean before the system is permitted to operate.

The ACR 2013 standard provides practical and reliable information for: assessing new and existing HVAC systems; evaluating and verifying the cleanliness of HVAC system components; preventing job related hazards; and guiding the cleaning and restoration of HVAC systems to a specific level of cleanliness.

Fms should assure that those responsible for cleaning their air conveyance systems to ACR 2013 are properly trained and qualified and possess relevant knowledge and experience before performing work. Industry certifications such as the NADCA Air Systems Cleaning Specialist (ASCS) or equivalent certification, may demonstrate minimum qualifications. Fms might refer to the ACR standard to review what information their service providers should provide them. This includes scope of work, methods of cleaning, project schedule, communication plan, product submittals, and safety plan.


The updated ACR 2013 standard helps fms to assess new and existing HVAC systems; evaluate and verify the cleanliness system components; and guide the cleaning and restoration of their systems to a specific level of cleanliness. Educating themselves on what service providers should deliver will maximize their investment.

Lantz is the general manager of Air Duct Cleaners of Virginia, an indoor air quality and environmental cleaning firm with offices in Chesapeake, VA and Durham, NC. He is a National Air Duct Cleaners Association (NADCA) certified Air Systems Cleaning Specialist (ASCS) and Certified Ventilation Inspector (CVI).


  1. Whoa, what is this? An actual article on HVAC and maintenance? I thought I was the only one that did that stuff lol.

    Great pieces of advice in here with regards to the new standard as well as maintenance practices. Too many times proper maintenance gets brushed to the side, one of my biggest pet peeves. When pm’s gets blown off, problems start to happen.

    My first Chief Engineer used to have a $5, $25, $100 analogy. Facilities can change the $5 belt to keep the fan running smoothly. If you ignore say a bad belt, eventually you might be replacing a $25 bearing. Ignore that bearing and you might be spending $100 for a new fan since you wrecked the shaft.

    Coil maintenance is vital as well as like cleaning the tubes on a chiller, ultimately it increases the efficiency of the plant as well as please the tenant (and reduce their cost maybe.)

    Anyways, I see your site is about facility management, I just started a site a few weeks ago about building engineering. I subscribed to follow-up comments so we can maybe get a discussion going. Thanks.

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