Air duct cleaning is generally available in various tiers or levels of service, ranging from a simple cleaning to comprehensive and something in between—“good, better, and best,” if you will. With a diversity of tools and techniques available, choosing the one that's right for you can be confusing. Here we'll break down the options available and which level of service is most appropriate for a given situation.
Standard Air Duct Cleaning
A standard air duct cleaning is a rudimentary cleaning—the “minimalist” approach. All air duct cleanings will consist of at least a vacuum and air pressure. The vacuum is inserted into the main trunk lines in order to create negative pressure in the ductwork system. Standard practice would then be to use air wands to blow high-pressured air into each of the vents in the branch lines to force debris toward the vacuum. Sometimes this process is helped along by air snakes or skipper balls in the main trunk. These tools consist of a metal ball at the end of an air hose that is fed toward the end of the line. Once engaged, air is forced out of tiny holes in the ball, blasting debris toward the vacuum as the tool is pulled toward the technician.
A standard cleaning might be an appropriate choice if your home’s ducts are well-maintained and cleaned regularly, as it removes small amounts of superficial debris; it is not effective for large amounts of debris or stubborn debris that clings to the sides of the ducts, like, for example, pet dander or drywall dust. It is important to remember that the only physical contact of the ductwork in the standard duct cleaning process is the sliding of the skipper ball across the bottom of the main trunks. The sides, corners, and top of the mains and the entirety of the branch lines remain untouched, but for air pressure.
Advanced Air Duct Cleaning
This mid-level cleaning is a more appropriate starting point in most cases, especially if you’re not sure how long it’s been since your home’s air ducts have been cleaned. It includes the vacuum and air pressure of the traditional cleaning but adds an additional measure in the form of an agitator—a tool designed to physically loosen debris and move it toward the vacuum, used in the main supply and the main return. Perhaps the most familiar agitation tool is the rotary brush--a round brush, attached to a cable, that spins inside the duct and brushes the top, bottom, and sides. Another popular agitator—and arguably more effective—is a multi-tentacled air whip (some brand names include the Octopus Predator or the Viper Clean Sweep). When engaged, the tool’s tentacles thrash vigorously every which way inside the ducts to knock debris loose and send it toward the vacuum.
Though the agitation tool renders the advanced a more thorough cleaning than the basic in terms of the trunk lines, the branch lines are typically limited to cleaning with high-pressured air, as they are in the basic cleaning. This advanced level of service is appropriate when most of the debris in the ductwork is located in the main supply and the main return lines. It should be noted that for some duct cleaning companies, this is their highest level of service.
Ultimate Air Duct Cleaning
Typically each level of service builds on the previous. So just as the advanced includes the process of the standard cleaning and adds the agitation tool in the main trunks, the ultimate or top-level cleaning includes all of the features of the advanced, with the addition of the use of an agitator in not only the main trunk lines but the branch lines (or vents) as well. Sometimes this tool is a smaller version of the agitator used in the mains (e.g. a Viper Microline), the size of which obviates the need to remove any register covers, and sometimes the same agitator is used as is in the main trunks, requiring removal of all register covers.
Because in this process an agitator is physically contacting all surface areas of the ductwork, it is the most thorough process available. This level of cleaning is appropriate on taking new ownership of a home, if pets are present, after new construction or remodeling has occurred, or if the homeowner just wants peace of mind that the ducts are as clean as they can be. Typically companies add on extras at this level of service, such as a furnace cleaning, sanitizer, before and after photos, etc.
When in doubt, have the technician assess
With all that said, if you’re not sure which level of duct cleaning your home needs, and you don’t want to spend more than you have to, most companies have a process whereby the technician can assess the condition of your ducts and make a recommendation before work begins. One of the considerations he’ll take into account is how many stories the home is; that is, how many stories up do the trunk lines extend before they feed into the branch lines and reach each of the rooms. If this is a great distance, you may want to use more than high-pressured air to clean the branch lines.
Another fairly reliable (and easy) method for determining how dirty your ducts are is to look inside the vents themselves. If there is a buildup of debris visible when you remove your register covers, it is a fairly safe assumption that the rest of your ducts have a similar buildup. A lack of buildup in the vents would suggest that the majority of debris is located in the main trunks, and the lower or mid-tier cleaning may suffice.
An experienced technician will be eager to share his knowledge and help you understand the reasons for his recommendation. Ultimately the choice is yours, but an understanding of the different processes involved, as well as knowledge of the setup and history of your home's HVAC system, will help to appropriately set expectations.
Wanna dig deeper? Download our free tipsheet: 10 Questions to Ask Before Hiring an Air Duct Cleaning Company.
Many thanks to our technicians Roy S and Ben S for lending their expertise to this article.