Those reputable companies that do provide duct-cleaning services tell a different story. They talk of extensive training, investment in proper equipment, and personnel who are certified to a rigorous standard. They also talk of happy customers who have been thrilled with their newly cleaned systems.

Assessing The Situation

Cleaning a homeowner’s ductwork isn’t an automatic process. For those contractors who belong to NADCA and adhere to the organization’s “Assessment, Cleaning, and Restoration of HVAC Systems (ACR 2002)” standard, the word “assessment” is the most important.

“We require our members to do an assessment and an inspection of the system to determine its cleanliness. They don’t just go out and clean. They take a look to ensure that it needs to be done, and if the system is dirty, they’ll clean it,” says Aaron Mindel, NADCA executive director, Washington.

Contractors adhering to ACR 2002 look for ductwork contaminants such as dust particles, mold spores, debris from rusted HVAC components, artificially made vitreous fibers, sand, and other particulates.

First Call Heating and Cooling, Portland, Ore., is a full service mechanical contracting firm. The company started offering duct cleaning in 1996, when customers started expressing an interest in improving their air quality and equipment life span. The company became a member of NADCA for credibility purposes.

“As a member of NADCA, we are required to maintain continuous educational credits and follow a stringent standard and code of ethics,” says Laura Dalby, IAQ supervisor, First Call Heating and Cooling. “Following NADCA ACR 2002, along with continuous educational courses is how we learn and continue to perform professional ventilation cleaning.”

Dalby notes that there are times they arrive on the scene to clean the ductwork, only to find it doesn’t need cleaning. “We’ve found ducts that are considered clean. That might occur, for example, when contractors have protected the ductwork during construction, or the customer contracted a qualified contractor to clean them in the past. HVAC systems need proper maintenance and efficient air filters to assist in keeping them clean.”

Other times Dalby says their technicians have found disconnected ductwork, areas where water intrusion has occurred, or where rodents have used the ductwork as a place to live. “A lot can be found by crawling in the crawl space or attic areas,” she says.

Benefits Are Many

Mindel says there is a definite benefit to cleaning ductwork, especially when it’s obvious to see that the system is covered in debris or contaminants. “It is definitely a worthwhile investment that will increase a system’s longevity, efficiency, and lead to cleaner air. There are ‘blow-and-go’ companies out there that are doing haphazard or questionable work, but not NADCA members. They’re committed to a higher standard and to do the work so that it actually has positive benefit and is a useful maintenance tool.”

Rick Crickenberger, salesman, Dusty Ducts, Forest, Va., says his company does a lot of HVAC cleaning work on the commercial-industrial side, as well as in the residential market. “My customers are the ones who tell us they either feel better or they’ve noticed a reduction in the dust in their house.” Customer testimonials confirm that cleaner coils and ducts help the system function better and provide a healthier indoor air environment.

He has seen ducts that were completely restricted with debris. “While the customer knows that they may have a problem with their air conveyance system, many times they are unaware of severe airflow restrictions and contamination issues. We are able to see the unseeable and then show our customers how to remedy the problem. That’s when our job is especially gratifying.”

Dalby adds that duct cleaning is definitely necessary, asking, “What if a customer doesn’t dust their house or office? How much dirt and debris will have settled?”

In new construction, in particular, she notes, the register openings are often used as dustpans. “We have found old lunch remnants, drywall pieces blocking airflow, and ductwork that is disconnected or was never installed. Duct cleaning done by a qualified contractor can remove built-up contaminants and improve indoor air quality.”

Crickenberger adds that in any industry there are going to be people who may not have customers’ best interests at heart and duct cleaning is no different. As the president of NADCA, Crickenberger says adhering to the NADCA standard is vital to maintaining a high industry standard. It also serves to separate the reputable contractors from the “blow and go” companies.

Duct Cleaning Requirements

Cleaning ductwork involves more than just vacuuming out the system. Simply put, NADCA’s ACR 2002 requires that the ducts be put under negative pressure in order to build containment. This keeps contaminants from blowing out into the environment. Then the system is agitated and any loosened debris are vacuumed out.

The actual cleaning procedure differs based on the type of ductwork. “With metal duct, you can hand clean it and use air whips and brushes inside it. For flex duct, the same methods can be used but extra caution should be taken, because you don’t want to damage the duct itself. If you’ve got fiberboard, again, you have to be careful because it’s a little more fragile than metal ductwork,” says Mindel. “What we’ve done is create a standard for cleanliness, and our members use different equipment and procedures to comply with the standard.”

The cleaning procedure goes beyond ductwork. Under the NADCA standard, the assessment procedure should also take into account all the components in the air-handling unit, including filters and filter bypass, heating and cooling coils, condensate pans, condensate drain lines, humidification systems, acoustic insulation, the fan and its compartment, dampers, door gaskets, and general unit integrity.

“That’s one of the main misconceptions,” says Mindel. “When you say ‘duct cleaning,’ people think you’re only cleaning the ducts. Our standards require that they clean the ventilation system and that includes system components as well.”

He stresses that cleaning the whole system has benefits from an air quality standpoint, as well as an efficiency standpoint. “If you look at a system that is covered in debris or contaminants, or has an inch of dust built up all the way around the duct system, it’s reducing the efficiency of the system. Just from an air quality standpoint, you want to get that out of the system, so it’s not blowing through anymore. And if the system is dirty, coils are blocked or have microbial growth on them, it’s taking more air to push through the system, and that costs money.”

Dalby and other contractors insist that properly cleaning the ducts and other HVAC equipment results in cleaner air and better efficiencies. “Duct cleaning is beneficial in all parts of the country. Dirt, dust, and debris are everywhere,” notes Dalby.

Publication date: 09/29/2003