Commercial duct cleaning technicians encounter a wide array of HVAC system setups, including different components and various materials. As such, they must have a diversity of tools and methods at their disposal, which they can vary depending on what will be most effective under the given conditions.
Crawl-through duct cleaning
When the ductwork is large enough for a person to fit into, a physical crawl-through will be conducted. Because during the process the technician is in very close proximity to the entire length of the ductwork, this is the most thorough and effective method of commercial duct cleaning available. During a crawl-through, the technician dons protection in the form of a Tyvek suit and a respirator. He enters equipped with a HEPA-filter vacuum with 100 feet of 1 7/8-inch hose and either a 3- or 14-inch dust-brush head. He physically enters the ductwork through a 16-inch access panel, moving methodically through parts of the HVAC system. When he reaches a fire damper or a set of turning vanes, he will create new access on the other side. All access panels will later be thoroughly patched with sheet metal according to NADCA (National Air Duct Cleaners Association) standards.
Tentacled air whips
If the ductwork cannot be cleaned by crawl-through because of its dimensions, a multi-tentacled air whip will be the technician's tool of choice (in the case of Twin Cities Furnace Cleaning, this is the Viper Clean Sweep System). This tool has six 14-inch long tentacles that thrash swiftly and vigorously around inside the ductwork in all directions. This extreme agitation loosens debris, and then a reverse- and forward-skipper ball, alternatively, is used to push debris to the desired location, where the vacuum is situated. This is accomplished by creating a minor access point in the middle of the length of ductwork and sending a back-skipper down one way, then the forward-skipper down the other way, again, toward the vacuum. (The Viper alone will be effective if there is enough suction, but a better practice would utilize the skipper balls in concert with the Viper.)
A rotating brush, or rotary brush, which is essentially a spinning brush-head on the end of a long cable, is a more traditional, less modern tool than the Viper but is still sometimes a better choice for particular conditions. It is often used in transit ductwork, for example, if there's been flooding, or if the transit lines have been compromised by cracks and sand has entered. In this case, the aggressive spinning of the carbide-tipped brush-heads will more effectively dislodge debris. These firmer bristles are also effectively used on uninsulated ductwork, whereas the softer rotary brush bristles are suitable for interior-insulated ductwork. Rotary brush-heads come in 4 sizes (to properly fit the ductwork) in both the hard- and soft-variety bristles.
High-pressured air triggers, etc.
High-pressured air wands or air triggers are a standard tool in any duct cleaning technician's arsenal. Because an agitator (air whip) or contactor (brush) is needed for effective cleaning of ductwork surfaces, air wands are not used alone to clean ducts. Commercially, these are most effective for cleaning components such as reheat coils; after a Viper, or a vacuum with a dust-brush head, has been used to loosen debris, a high-pressured air trigger blows it through the coil to the vacuum. Even something as simple as a foxtail duster is a valuable tool in specific situations, such as cleaning turning vanes and dampers, along with a vacuum.
Of course, the multiplicity of tools and methods available to commercial cleaning technicians is valuable only to the extent that their experience guides them as to which is the proper tool for the given HVAC component/scenario.
Wanna learn more? Have a look at our Commercial Duct Cleaning and Commercial Dryer Vent Cleaning service pages.
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Many thanks to our commercial project manager Ben S. for lending his expertise to this article.
As with air duct cleaning and chimney cleaning, dryer vent cleaning often entails a few surprising and sometimes disconcerting finds. The diversity of these discoveries and the troubleshooting necessary to resolve them benefit our techs in contributing to their arsenal of skills, and our customers in the form of knowledge and advice conveyed by the tech.
What is dryer vent cleaning?
The purpose of cleaning a dryer vent is to ensure that the line of ductwork that runs from the clothes dryer itself to the vent outside the house is completely clear of lint and other debris. Dryer lint is highly flammable, and a clogged vent is a serious fire hazard.
When cleaning a dryer vent, if the technician does not observe air flow from the outside vent, indicating the line is clear and the ducting is properly connected, he’ll look for the source of the problem; in the absence of air flow, he knows the vent line is either clogged or disconnected.
(Want to learn more about the dryer vent cleaning process? Visit our dryer vent cleaning service page.)
How does the technician check for dryer vent disconnects?
One of our technicians, Roy S, recently described how he listens for signs of success or failure.
“I listen, and I can hear my [air] snake go down the vent. If the sound of my snake disappears and all of a sudden there’s nothing, I know my snake has left the vent. When we’re outside cleaning the vent, we can hear it blowing air back at us—we can always hear it. Even if the vent is really dirty, the sound of the snake will get a bit muffled moving past the dirty spots, but we can always hear it. Once the sound cuts out, you know the snake traveled its way through a disconnect.”
He further described how he knows the vent is clear: “When I can hear the motor on the dryer running, that’s how I know everything is clear and there’s no obstruction. Once the line is all clean, you can hear it plain as day. I never leave a job unless I can hear the motor on the dryer.”
This is only one strategy, of course. Different technicians will likely use various strategies, and an experienced technician knows which strategy is most appropriate for the circumstances. (For some foundational knowledge on dryer vent cleaning and how to find an experienced technician/company, download our free tipsheet: 5 Questions to Ask Before Hiring a Dryer Vent Cleaning Company.)
What is a dryer vent disconnect and why is it a problem?In townhomes in particular (for reasons that are unclear), our technicians sometimes find that when a dryer vent runs through the attic, the vent tube is lying on the floor of the attic rather than properly connected to the vent on the roof, spewing its exhaust into the indoor environment of the attic rather than to the outdoors, where it belongs. Obviously this is a very poor practice, as venting a dryer directly into the attic—or anywhere indoors for that matter—can cause a lot of moisture damage to walls, ceilings, and other areas, leading to rotting or mold. In cases where our techs have witnessed this kind of disconnect, customers had often previously noted high levels of moisture or signs of mold in key places, such as the corners of bedrooms and in the attic itself.
Of course, any disconnect needs to be repaired before a proper cleaning can be performed and before the machine is run again. If it is the case that the vent tube is too short, as it is often with the townhome-attic disconnects, it is merely a matter of connecting a new length of flexible ductwork to the old and then connecting it to the outside vent. Sometimes the dryer vent cleaning technician can do this himself, if properly equipped and experienced, and sometimes the customer will be instructed to call a repair company. If the disconnect occurs on a managed multi-unit property, the owners should be made aware, as there are likely other disconnects elsewhere on the property.
Although dryer vent disconnects can cause a lot of damage when left unchecked, once identified, they are often easily repaired/reconnected, and the property owner (and technician) are wiser from the experience.
Wanna dig deeper? Download our free tipsheet: 5 Questions to Ask Before Hiring a Dryer Vent Cleaning Company.
Many thanks to our technician Roy S, for providing the case notes and quotes for this article.
Air duct cleaning technicians discover, as you can imagine, all sorts of strange things in the field—some dangerous, some gross, some merely annoying—but all can be learning experiences. For the tech, this learning comes in terms of increasing their troubleshooting skills and adding to their body of knowledge on how best to handle complex situations. For the customer, the lesson learned is in terms of things not to do, or things to watch out for.
A relatively frequent discovery for our techs, often to the surprise of the homeowner, is the practice of running cables (phone, internet) or cords (appliances, phone) through the air ducts, presumably because they provide an existing and fairly direct conduit that does not require drilling any new holes into walls or floors. If someone needs to run a cable, cord, or wire from one part of the house to another, and Sheetrock or flooring is in the way, well, an air duct may seem like a logical solution.
What’s the problem with running cables through air ducts?
In many cases, it was a previous homeowner who placed the cables or wires in the ducts, and for whatever reason their presence was not noted during the new home inspection, leaving the current homeowner unaware.
The fairly obvious problem with this practice is that the ducts were designed to be conduits for air—not wires. In most locations this would violate code unless very specific conditions were met. But beyond that, the running of cables and cords through air ducts could be disastrous when the ducts are cleaned, particularly if the homeowner and/or technician is unaware of their presence—and especially if a rotating brush is used during the cleaning.
What is the best way to clean air ducts with cables in them?
Now, not to endorse the practice of running cables through ducts, but there is a workaround, if the ducts need to be cleaned and the cables, for whatever reason, cannot be immediately removed: an air whip—and in the case of this particular job and the accompanying photos, specifically, the Viper Clean Sweep.
The reason? A rotary brush sweeps the ducts with a spinning motion, in a single direction, thereby catching up and twisting and mangling any cords or cables it catches, in some cases, as our techs have documented, ripping out wires that were servicing a particular area of the house, taking out appliances, etc. Because the tentacled air whip, or the Viper, works by thrashing and whipping quickly and repeatedly, each time retracting without “grabbing onto” anything, it can clean around any wires or cables without damaging them.
(Interested in learning more about the air duct cleaning process? Visit our air duct cleaning service page.)
First lesson: It’s not wise and would likely violate your local code to use the air ducts as a conduit for running cables, cords, or wires. Second lesson learned: if they are already in place and you, for whatever reason, choose not to remove them but need the ducts cleaned, steer clear of rotating brush methods and opt for an air whip cleaning.
Wanna dig deeper? Download our free tipsheet: 10 Questions to Ask Before Hiring an Air Duct Cleaning Company.
Many thanks to our technician Roy S, for providing the case notes and photos for this article.
If you came across this article as a result of an internet search, you may have noticed there aren't a lot of search results for "furnace duct cleaning." It’s not a conspiracy but rather a matter of diction: the more common term is “air duct cleaning.” The process is also sometimes referred to as “HVAC duct cleaning” or “vent cleaning.”
Furnace duct cleaning—or air duct cleaning—is the process of removing contaminants and debris from the ductwork associated with the HVAC (Heating, Ventilation, and Air Conditioning) system. This ductwork is sometimes referred to as furnace ducts because they originate at the furnace—the heat source—and serve to distribute heated (or, in some cases, cooled) air throughout the building or home, exiting at the vents or diffusers.
What is the process for furnace duct cleaning?
There are a variety of methods for cleaning furnace ducts, but generally the process relies on a dual approach, referred to as the “push and pull method.” The first aspect relies on a powerful vacuum applied near the furnace to create negative pressure, or sucking in of the debris to a containment system, preferably off-site, such as a truck. The second aspect of the service involves the utilization of agitation equipment, such as pneumatic air whips or rotating brushes, which essentially jostle around inside the ducts and loosen any debris, which is then sucked up by the vacuum.
Still have questions about the cleaning process or the various levels available? Visit our air duct cleaning service page.
What is the difference between furnace duct cleaning and air duct cleaning?
In short, nothing at all. Some companies that refer to their service as “furnace duct cleaning” rather than “air duct cleaning” may perhaps do so because they include the furnace as part of the duct cleaning process. Since the furnace and ductwork are all connected and continuously circulate air throughout the system, if one component is dirty and in need of cleaning, the other likely is too—so cleaning the furnace along with the furnace ducts is almost always the best approach (unless, as happens every so often, customers are having their ducts cleaned because they’re getting their furnace replaced). Always check with the company, though, to find out what components are included during the cleaning service, as it is not necessarily standard practice to include the furnace in an air duct cleaning without additional cost.
Where can I find out more?
Now familiar with the lingo, you’ll find a wellspring of information available in a search for “air duct cleaning.” Interested in finding out what tools are used during the process? Check out our blog article, Tools and Equipment Used During Air Duct Cleaning. Want to read about each of the specific levels of service available and the precise process it entails? Visit our air duct cleaning service pages. Considering having the service performed?
Download our free tipsheet: 10 Questions to Ask Before Hiring an Air Duct Cleaning Company.
What is HVAC Cleaning?
HVAC (Heating, Ventilation, and Air Conditioning) cleaning involves the removal of dirt, debris, and contaminants from the individual components of a building’s HVAC system, either in a residential or commercial setting.
In a residential setting, these components would likely include the furnace (including the blower wheel), supply and return ductwork, evaporator coil (A-coil), etc. Commercial components cleaned would include the air handling unit (AHU) or rooftop unit (RTU), supply and return ducts, coils, VAV boxes, supply diffusers and return grilles, etc.
How is the HVAC System Cleaned?
Each of the various HVAC components calls for a different method of cleaning. Air duct cleaning is typically accomplished with the application of high-pressured air and/or whips or brushes that physically sweep debris from the ducts, in combination with negative pressure in the form of a vacuum to capture debris and contain it off-site.
Furnaces are typically cleaned using mostly air pressure, with some parts (e.g. flame sensor) being physically wiped down. For the evaporator coil, light brushing with air pressure (so as not to bend the delicate aluminum fins) and possibly the application of a cleaning solution is typical. In some cases, the coil may be removed completely and washed outside (a process that would command a higher labor cost). The outside AC condenser unit, which also requires routine maintenance, can be cleaned of leaves and other outdoor debris with the application of air pressure and water, often from a garden hose. The homeowner should make sure surrounding foliage is trimmed regularly.
For commercial HVAC cleaning jobs, an on-site assessment will determine the most appropriate cleaning method, which, regarding the ducts, could involve anything from the use of air whips/power brushes and contact vacuuming to a physical crawl-through by the technician. Air handler components may be cleaned with high-pressured air, surface cleaning, or air whips, depending on their size and how much access is available. A walk-in handler would be cleaned using a pressure washer and wet-vac. Grilles, grates, and diffusers are usually hand-wiped and ideally degreased.
Why is HVAC Cleaning Necessary?
It’s all about air flow—to ensure proper operation and efficiency of the HVAC system and all of its parts. If the filter is dirty, air flow is restricted. If the blower wheel is dirty, air flow is restricted—you get the idea. If all the system components are clean (barring any repair issues), you can feel confident your system is running at top efficiency. In a commercial environment, again, having clean VAV boxes, coils, and dampers allows air to flow to its destination unhindered.
But it’s also about indoor air quality. Air moving through a dirty HVAC system is going to pollute the indoor environment. To save your family (or your employees) the discomfort and ill effects of breathing contaminated indoor air, investment should be made in regular system cleaning. Additionally, when the visible components of the system (vent covers, grilles, grates, diffusers) sparkle, occupants can have confidence in the overall cleanliness of the HVAC system and the air it circulates. Many of us have probably experienced the unsettling feeling of wanting to hold our breath at the sight of blowing dust-bunnies clinging to filthy air vents!
When Should the HVAC System be Cleaned?
For commercial cleaning jobs, the suggestion would be every 5 to 10 years. Most commercial cleaning companies will send a technician to the property at no cost to assess the system and discuss project scope and overall cost. For residential jobs, the general guideline would be every one to three years, as well as after any disruptive event such as laying new carpet, polishing/sanding wood, remodeling (particularly if drywall is involved), etc. Basically, conditions that tend to generate debris would warrant more frequent HVAC cleaning. Or, in the frank words of one of our technicians, “If they’re running a cat hotel, they probably want to have their system cleaned yearly.”
A good rule of thumb: if the appearance of the ceiling tiles, vents, or diffusers is unsightly, then it’s fair to question whether the cleanliness of the system is compromised and you should consider having it assessed for cleaning.
How Much Does HVAC Cleaning Cost?
Cost and quality will vary greatly among companies. For residential jobs, furnace cleaning will generally range from $50 to $500, with the (much) higher price range presumably including the evaporator coil—the cleaning of which can be quite labor intensive. For air duct cleaning, HomeAdvisor calculates the range nationally at between $120 and $675. Factors that increase the cost of the service would include having more than one system, the size of the home, and the level of service desired.
The main thing to bear in mind when considering the cost of services is whether there may be any charges you haven’t considered, or, more nefariously, hidden costs. During your conversation with the company while you are in the consideration phase, ask questions designed to flesh out these possibilities, such as “Is there anything that may increase the cost of the service that I haven’t considered?” Or more directly, “Are there any hidden costs?”
On the flip side, ask also if there are any discounts for first-time customers, subscribers to the company newsletter, online booking discount, etc. Many companies offer these types of incentives.
Now that you’re familiar with HVAC basics, feel free to dig deeper by exploring some of our HVAC cleaning service pages, including a detailed description of the cleaning process and pricing.
Many thanks to our technicians Roy S. and Ben S. for lending their expertise to this article.