Why Are There Little Black Plugs On My Air Ducts?

Small Black Circular Plug on Air Duct
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If you are down in your crawlspace, unfinished basement or utility room, you may see plugs in your air ducts or ventilation trunk lines. These plugs come usually in silver or black. The plastic plugs fit into one-inch holes that were drilled into your ducts during air duct cleaning.

Are The Plugs On My Air Ducts Helpful Or Harmful?

When air ducts are cleaned properly, a technician will drill one-inch holes on supply ducts and trunk lines to insert pneumatic agitation tools. The tools can be whips or nozzle tools with multiple rear or forward-facing jets. The agitation tools can be mounted on flexible air hoses or bendable rods that fit together in sections.  

When you see these plugs or caps, it is a good sign. It means there is a high likelihood your ducts have been cleaned in the past by a skilled air duct technician. It is also helpful because when you have them cleaned again, the technician will likely not have to drill new holes. The old plugs are simply removed and discarded. An expert technician will install new plugs into the holes to ensure a tight seal on your ventilation system.

What Are Those Square Plates On My HVAC System?

You may also notice square plates that have been screwed into your supply and return trunk lines. The bigger plates were where the vacuum truck suction hose was installed. The smaller plates cover the holes where the technician may have inserted a rotary brush tool. The smaller hole usually four inches in diameter is also a great place for the technician to insert a camera for before and after pictures.

Why Planet Duct Is The Best Air Duct Cleaner | Get A Free Estimate

As an air duct technician, I often hear customers throughout El Paso County say their air ducts were professionally cleaned in the past. When I notice that there are no plugs on the ductwork, it is a clue that the service was not completed by a professional. Unfortunately, many carpet cleaning companies will claim to clean ducts, but their carpet cleaning machine was not made for duct cleaning. They may be able to agitate the dirt in the duct, but the suction from their truck is inadequate to remove the debris.

The absence of access holes on a duct system that was allegedly cleaned is a red flag to a professional duct cleaner. When we do not see duct plugs, it tells us that the cleaning was not done to the NADCA (National Air Duct Cleaners Association) standard. The standards are in place to ensure that cleaning is done correctly. It is also established to ensure the health and safety of building occupants and workers.                                    

The exception to the rule is finished basements where the ducts are not visible. Because the ducts are not fully visible, we cannot drill the one-inch access holes. We can still clean the truck lines from the utility room.  However, to clean the supply ducts we would instead need to send a forward-facing nozzle tool down through each one of the supply ducts in each room. Doing this may require the removal of screwed on vents which will take more time. If this was necessary, we would need to get customer approval first as many duct vents have been painted over.

At Planet Duct, it concerns us when we speak to neighbors throughout Colorado Springs and learn that their air ducts were not professionally cleaned. It is important to beware of poorly trained air duct cleaning technicians with cheap equipment, because they end up costing you more without really improving your quality of air. We believe in educating our community so that everyone is taken care of. Our team has been thoroughly trained, NADCA certified, and only uses the very best air duct cleaning equipment to improve your home’s air quality. Contact us to learn more, get a free online estimate, or simply ask about all of the components of your HVAC system to learn more.