Importance of Duct Cleaning

Over time, dirt, dust, pet dander, debris, and more accumulate in air ducts. And since the HVAC system works basically as a whole-home vacuum, all of that is recirculated through homes when the HVAC system runs, reducing IAQ.

“Cleaning your air ducts helps remove these pollutants, leading to cleaner air and a healthier living environment,” said John Kovacs, vice president of sales at Rotobrush. “For individuals with allergies, asthma, or other respiratory conditions, air duct cleaning can help reduce the presence of allergens and irritants in the home. This can alleviate symptoms and improve overall comfort.”

Clean ducts can improve the overall cleanliness of a home, Kovacs said. Moisture trapped in air ducts can lead to mold growth, which also negatively impacts IAQ and poses health risks. Duct cleaning can not only prevent mold from developing and spreading throughout a home, it can also help remove odor-trapping particles from things like mold, pets, or smoking, or cooking, and leave the home smelling cleaner.

It’s no secret that a clean and maintained HVAC system can help prevent breakdowns and costly repairs, making the equipment last longer. To maximize this, regular maintenance has to include air duct cleaning.

“When duct systems are designed, they're designed with certain ‘laws’ in mind, if you will … and duct design requires ducts to be a certain size in order to carry the specified volume of air,” said Justin Tarr, owner of Daffy Ducts in Atlanta.

AIR FLOW: The smoother the air ducts, the cleaner the airflow, and the better the IAQ. (Courtesy of Daffy Ducts)

As air moves through the ducts, it interacts with surfaces. The smoother the duct, the more easily air can move throughout it.

“Let’s say your return side is designed to be 10 inches in diameter, and there’s two inches of surface coating consisting of [dirt, dust, debris] that’s built up over several years; now the airflow through that duct only has an eight-inch opening now,” Tarr said.

If air is still flowing sufficiently, it’s meeting resistance, because it’s not flowing through a smooth interior.

“When all that happens, the system has to work harder and struggle to try to pull in the air that is designed to pull in, to be able to push that back out the other side, which reduces the lifespan of the actual equipment,” Tarr said.

When an HVAC system doesn’t have to work as hard to push air through clogged ducts, there is less strain on its components, Kovacs said. This extends the lifespan of the equipment by reducing the frequency of repairs and replacements (also reducing the frequency of those associated costs for HVAC contractors).

A more efficient HVAC system also requires less energy to function, which can lead to lower utility bills for homeowners. A reduced workload for the HVAC system — in this case specifically, cleaner ducts for easier airflow — can contribute to overall energy and cost savings.

“When air ducts are clogged with dust and debris, your HVAC system has to work harder to maintain the desired temperature,” Kovacs said. “This can lead to increased energy consumption and higher utility bills. Cleaning the ducts ensures that air can flow freely, improving the efficiency of your HVAC system.”

Knowing Ducts

There are a few misconceptions regarding duct cleaning that could be said to be hindering its success, such as how to thoroughly clean ducts and how often to clean them.

THE RIGHT WAY: When ducts are properly cleaned, the process should be lengthy. (Courtesy of Ductz)

“You can clean just your trunk and branch lines, but you should also be cleaning the blower motor, the drain pan, the evaporator coil, your registers — you should be cleaning all the components as well, to make sure that the entire system is clean, not just your ducts,” said Jessica Wicks, brand president of Ductz. “Because if you don’t, as soon as you power that system back on, you’re just going to re-contaminate.”

While duct cleaning can improve IAQ by removing contaminants from the ductwork that would otherwise be recirculated, it’s not a be-all, end-all solution. It’s only one part of providing a healthy IAQ to homeowners. It’s also not a “one and done.” Dust, debris, mold, and the like develop over time, so periodic cleaning may be necessary.

“Especially if there are specific circumstances like home renovations, pest infestations, or water damage,” Kovacs said.

Because there are so many factors at play that could affect how dirty each homeowner’s duct system is, there is no real recommendation for how often a homeowner should clean their ducts.

The National Air Duct Cleaners Association (NADCA) does, however, have a recommended inspection schedule. To maintain an efficient HVAC system, NADCA recommends getting air ducts inspected once a year, and cleaned as needed.

“NADCA does say, residentially, you should have the air handler checked yearly, and that's often done right by your HVAC contractor,” said Wicks. “And then every two years, you should have your supplies and return assessed. As a homeowner, you can do that if you're noticing that your return registers are caked and filled with debris. That means there's a lot of debris in your ductwork, and then you should have us come out and take a look.”

Another thing that NADCA does is define what “clean” really is, according to its Assessment, Cleaning, and Restoration (ACR) standard.

“One consistent requirement is ensuring that there's some type of negative pressure setup with the [duct] system for proper containment of any debris or microbial contamination that is lifted up into the air stream from the air side surfaces of the duct,” Tarr said. “Placing it under negative pressure and utilizing multiple different types of vacuums is critical in proper containment of those items.”

Having air ducts cleaned is a rather lengthy process; it takes time to do it the right way.

“When you have a service of that magnitude … it should take several hours, it should be a process where they're blocking off the supply and blocking off the return, cleaning the air handler separately, where the registers are washed as well,” Wicks said. “If someone says they are going to come in and do it in 45 minutes, it's not being taken care of properly.”

Offering Duct Services

Duct cleaning makes the job of an HVAC contractor/technician that much easier, as it prolongs to lifespan of equipment and enhances the livability of their homeowners.

As far as in what capacity they should offer it, HVAC contractors have a couple of standard options. They could offer duct cleaning services themselves, ensuring their technicians are trained on what to clean and how to clean it. Or they could partner with a duct cleaning company.

In Tarr’s personal opinion, HVAC contractors should partner with a professional duct cleaning company — or partner to subcontract, or partner to refer. He’s seen too many HVAC companies dive in without being well-versed in proper cleaning techniques or equipment, leading them to get into the market and then get back out. For some, it wasn’t consistent enough work to invest in as a service; for others, it required another level of management, supervision, and oversight on something that really wasn't a specialization for HVAC, leading to additional expenses.

“Duct cleaning is a niche in and of itself, so I think that HVAC contractors should find a good, reputable company to work with on doing duct cleaning,” he said. “When they find a good company that they can refer to their homeowners or work with to subcontract, then they know they're working with somebody that [provides duct cleaning] day-in and day-out, understands all the ins and outs, and isn’t going through all of the potential turnover, recruiting, and onboarding situations that happen in duct cleaning,” Tarr said.

HVAC contractors looking for a reputable duct cleaning company to partner with can start through NADCA — then, of course, shop around to find the duct cleaning company that’s the best fit for their company’s values, goals, and mission.

HVAC contractors who do opt to offer duct cleaning services themselves, and do so effectively, report more control over the quality and consistency of the service, an additional revenue stream, and enhanced customer trust.

“It provides an additional source of income, enhancing the overall profitability of the business,” Kovacs said. “This service also allows the contractors to offer a full duct cleaning at the same time as an equipment change-out to ensure the brand-new coils that were just installed do not become the filters for the dirty air ducts.”

Kovacs also said that contractors who offer the service can bundle duct cleaning with other services like HVAC maintenance, repairs, or installations, offering package deals that provide value to their customers.

However contractors choose to offer duct cleaning, they’ll see a number of benefits to their business by doing so. They’ll increase customer satisfaction, as their customers won’t have to look elsewhere for this added service, increasing retention and allowing them to win more change-out bids. It’s also a great market differentiation, compared to those who don’t offer duct cleaning, and improves the company image.

“Being a one-stop shop for HVAC and duct cleaning services can build stronger long-term relationships with customers … Being known as a comprehensive HVAC service provider can enhance the contractor’s reputation in the market,” Kovacs said.