The business of cleaning air ducts is a messy one. Because of the HVAC system's tight, enclosed spaces coupled with moving parts, it's not a welcome environment for small creatures. Sensitive readers may want to skip this article.
With that said, sometimes it's better to let the technicians do the talking, so here they are:
Steve E: "We were in the process of cleaning a cold air return located in a customer's basement bedroom. Attempting to place a whip into the vent, I had difficulty moving it entirely into the cavity above to reach the trunk line. Several attempts later, I decided to reach in with my hand, and I quickly pulled out a revolver-style handgun that had been hanging on a nail lodged into the wall. When we notified her of our discovery, very nonchalantly this customer replied, 'Oh yeah, I had a crazy ex-boyfriend at one time who used to hide guns all over this house—don't be surprised if you find more!'"
Dave C: "These pictures are just an example of some of the things we see in venting. The first one is a dozen cookies, a PBJ sandwich, and toys that a small child put in the vent. The customers had been complaining of a weird smell in the house."
DC: "In newly constructed homes we often find 'cutoffs' in the vents, such as Sheetrock, 2x4 ends, nails . . . and garbage."
DC: "This customer was getting ready for work and had a diamond earring sitting on the end of the counter. She heard it fall into the vent but couldn't reach far enough down to grab it. I was about an eighth of an inch from not getting it, but in the end I did."
DC: "Never put mouse traps near vents! In this case a mouse got caught and dragged the trap further into the vent, then got away. It died further down the vent."
Ben S: "Commercial ducts are a lot larger than residential ducts, so discoveries there get a lot weirder. At a college in Minneapolis, a homeless person had bent back a fresh-air grate that led into the duct system and had been living there for many weeks. During that time they acquired a full bedroom set, a couch, and a five-gallon bucket for use as a bathroom. The occupant was not present when we made the discovery, so we are unaware of where they relocated to."
BS: "At a technical college, when cleaning out the exhaust system for the bathrooms, below the exhaust fans we found 24 decapitated birds. It appeared they had flown into the fan, as their bodies were severed from their heads, and some of the bodies remained on the roof."
BS: "At a correctional facility, while cleaning out supply vents that feed into the inmate cells, we found contraband that they had stuck down the vents before their cells were raided. We found prophylactics, used needles, homemade knives, razor blades. homemade alcohol, etc."
Seized by a sudden urge to have your air ducts cleaned? Learn more about the process on our air duct cleaning service pages.
Wanna dig deeper? Download our free tipsheet: 10 Questions to Ask Before Hiring an Air Duct Cleaning Company.
Many thanks to our technicians Ben S, Dave C, and Steve E for lending their expertise to this article.
Technician experience matters.
It seems like a simple job, air duct cleaning—some DIY folks even do it with a vacuum and a leaf-blower, right? The truth is, the HVAC system and its associated ductwork are complicated and diverse. Their condition and cleanliness are vital to your air quality and home comfort and therefore should not be entrusted to a novice.
An experienced tech makes judgments based on observation.
An experienced technician can quickly assess, with a visual inspection, how dirty the ducts are and even how well they were cleaned previously. This would be achieved by a brief visual inspection of the furnace, removal of the filter and peering up the return plenum, as well as a quick look inside the return vents on the main level. He'll also check to see if access holes for the tools and vacuum were cut in the appropriate places and sufficient for the configuration/extent of the home's ductwork. He'll know, based on experience, what questions to ask the homeowner to determine the appropriate level of cleaning.
A savvy tech will be able to spot an inferior duct cleaning job and appropriately counsel the homeowner. For example, our technician Dave C. points out that sometimes he enters a home to find that an access panel is too small to have accommodated an industrial vacuum and that likely an under-powered one was utilized (e.g. a shop-vac), suggesting an insufficient cleaning. Or perhaps on an expansive duct system he'll observe only a few duct plugs, suggesting that access points for the tools were not numerous enough to accomplish a thorough clean of the entirety of the system. A tech who observes the absence of an access hole in the supply line would reasonably conclude that only the returns were cleaned. Similarly, the absence of duct plugs in the ductwork in the mechanical room would suggest that the vents were merely blown out, leaving the main trunks uncleaned, and worse, the furnace and filter (rather than a vacuum) to catch the onslaught of debris. The observations of an experienced tech will help him to better educate and advise the homeowner.
An experienced tech chooses the right tool and method for the job.
Perhaps most importantly, an experienced technician will be better equipped to select the most appropriate tool and method for a particular job. Duct cleaning is not one-size-fits-all. For a straightforward residential system configuration with no air-flow issues, obstructions, or contamination, an inexperienced tech may well do a sufficient job. Throw a few curve balls, however, such as transite ducts or a system with cables running through it, and what might otherwise have been a fine result will be far inferior.
In a commercial duct cleaning setting this experience is even more critical, as these systems are vastly more complex (and costly). Commercial Project Manager Ben S. emphasizes the importance of tech experience in making sure commercial jobs run smoothly, where strict lockout-tagout policies need to be applied as well as strict adherence to OSHA procedures. A savvy commercial tech will not only ensure that all proper procedures are followed but that the most effective cleaning method for the diversity of commercial systems is utilized.
An experienced tech understands his limitations.
While a seasoned technician is adept at trouble-shooting, having a vast pool of knowledge and experience to draw from for each new experience, he also understands that sometimes more than a cleaning is needed to solve a problem.
Air-flow issues are a good example. Duct cleaners are often called upon to solve issues of insufficient air flow in a home. Sometimes these can quickly be attributed to damper issues or a clogged A-coil, but often they cannot (leaks or holes in the system are often to blame), and a repair company must be summoned.
One of our technicians, Nick M., recently went to a job in an older home in Richfield, Minnesota, where the homeowner was experiencing severe allergies and hoped an air duct cleaning would ameliorate her symptoms. Our technician quickly ruled out a sufficient cleaning based on his visual observation of the ductwork setup: 70% of the return ducts were covered in Sheetrock, preventing appropriate access (even though they had had their ducts cleaned on a previous occasion). Nick informed the homeowner he would not be able to do a proper cleaning as a result. The homeowner opted to have access cut into the Sheetrock and the duct itself, and the installation of a vent. Now they have a functioning return in their basement, as well as an appropriate access point for cleaning.
So go ahead and cut corners and costs on tasks you're not heavily invested in, or on those affecting minor systems or equipment, but trust your HVAC system only to someone who's been around the furnace a few times, or preferably, many more than that.
Wanna dig deeper? Download our free tipsheet: 10 Questions to Ask Before Hiring an Air Duct Cleaning Company.
The A-coil (or evaporator coil) gets its name from its triangular shape and is a critical component of your HVAC system. It is usually located above the furnace. All the air that circulates through your system passes through the A-coil before it exits the supply vents into the desired rooms, whether your system is heating or cooling. For this reason, it is highly susceptible to buildup of dust, dirt, and contaminants. Keeping the A-coil clean of buildup is one of the most important things you can do for your HVAC system. When it is dirty or clogged, air flow is greatly compromised, causing your system to work much harder to achieve the desired temperature.
What are the signs of a clogged A-coil?
Of course the surest sign of a clogged coil is its visual appearance, in cases where it is accessible and not encased. (The one pictured above is a casualty of "filter bypass," with all manner of debris, including dog hair, bypassing the air filter and adhering directly to the coil.) Even the thinnest layer of grime covering its fins will significantly decrease air flow. One of the first indications a homeowner will usually have of a dirty A-coil is diminished air flow from the air vents (though this could also be caused by a damper control issue). An increase in monthly heating/cooling costs often accompanies a dirty A-coil as well, as the system must work harder and use more energy to reach the target temperature.
What causes a clogged A-coil?
The A-coil will naturally dirty over time, since it is consistently exposed to the air being circulated by the blower. There are, however, several key factors that will contribute to its becoming dirtier than usual, or becoming dirty more quickly than usual, and most of these are filter-related. A too-cheap air filter will often allow particles too large to pass through, resulting in more debris becoming clogged between the fins of the coil. An incorrectly sized or ill-fitting filter can allow for filter bypass, when debris is able to sneak around the filter and directly into the components of your furnace, particularly the A-coil. Of course, many a technician has opened up a furnace to find no filter at all, which is obviously extremely detrimental to the furnace components, which must be clean of debris in order to effectively transfer heat and use energy efficiently.
How is an A-coil cleaned?
A-coils are situated on top of the furnace and are often "hidden" behind a panel and may or may not be reasonably accessible. Before cleaning, an access point is created directly above the coil so the technician can look from above to see where he can safely cut to access the side of the coil without puncturing any of the copper lines. Once access is created there, the technician can cut access into the underside of the coil, where the cleaning tools will be inserted. Tools used will vary depending on the job but generally include high-pressured air wands, an air whip (such as the Viper), an industrial-strength vacuum, a three-inch round dust-brush head, and sometimes non-rinsing coil cleaner.
How much does an A-coil cleaning cost?
Coil cleanings vary widely in price, mostly due to issues of accessibility, but how dirty the coil is will affect the price as well. Most companies will bid A-coil cleanings rather than advertise set prices, because the nature of the job will differ greatly from one unit to another.
It's well worth keeping in mind that whatever you spend to get your coil cleaned will easily be recovered in the form of increased energy efficiency, lower heating and cooling costs, and increased lifespan of your unit.
Many thanks to our technician Ben S for lending his expertise to this article.