What Can I Expect During an Air Duct Cleaning?

We have been discussing the topic of air duct cleaning, including the controversies and how to select a reliable service provider, in a couple of recent blogs. In this article, the helpful staff at GAMA Air want to help you with some tips on what to expect from an air duct service provider as well as how to determine whether a thorough job was done.

While it’s true there is much controversy over the need to have your air ducts cleaned, if you decide to have your ducts cleaned, the following is a list of things you should expect the service provider to do:

  • Open all of the access ports or doors to allow the entire system to be cleaned and inspected.
  • Inspect the heating and cooling system before cleaning to be sure that there are no asbestos-containing materials (for example in the insulation, register boots, etc.). [Asbestos-containing materials require specialized procedures and should not be disturbed or removed except by specially trained and equipped contractors.]
  • Use vacuum equipment that exhausts particles outside of the home. Or if using a vacuum that exhausts inside the home, it should be high-efficiency particle air (HEPA) vacuuming equipment.
  • Provide protection for carpet and household furnishings during cleaning.
  • Use care when brushing the duct surfaces and always in conjunction with contact vacuum cleaning to dislodge dust and other particles.
  • Use only soft-bristled brushes for fiberglass duct board and sheet metal ducts internally lined with fiberglass. (Although flex duct can also be cleaned using soft-bristled brushes, it may be more economical to simply replace accessible flex duct.)
  • Use care to protect the duct work, and seal and re-insulate any access holes that were used so they are airtight.
  • Follow NADCA's standards for air duct cleaning and NAIMA's recommended practice for ducts containing fiber glass lining or constructed of fiber glass duct board.

Did the Duct Cleaner Do a Thorough Job?

So, the service provider has finished cleaning the air ducts and you’re wondering if they did a thorough job. Of course, a visual inspection is the best way to verify the cleanliness of your heating and cooling system. So, some service providers will use remote photography to document conditions inside ducts and the cleanliness afterward. All portions of the system that you can see should be clean and without debris. Below is a Post-Cleaning Consumer Checklist which can help you determine that a thorough job has been done. You can go over the list with the service provider and ask him to show you each component of your system to verify that the job was performed satisfactorily. Do not consider the job done until you can answer “Yes” to each of the questions.

Post-Cleaning Consumer Checklist:


1.       Did the service provider obtain access to and clean the entire heating and cooling system, including ductwork and all components (drain pans, humidifiers, coils and fans)?

2.       Has the service provider adequately demonstrated that duct work and plenums are clean? (A plenum is a space in which supply or return air is mixed or moves – this may be a duct, joist space, attic and crawl spaces, or a wall cavity.)


3.       Is the heat exchanger surface visibly clean?

Cooling Components

4.       Are both sides of the cooling coil visibly clean?

5.       If you point a flashlight into the cooling coil, does light shine through the other side? (If it does not then the coil is not clean.)

6.       Are the coil fins straight and evenly spaced (not bent over and smashed together)?

7.       Is the coil drain pan completely clean and draining properly?


8.       Are the blower blades clean and free of oil and debris?

9.       Is the blower compartment free of visible dust or debris?


10.     Is the return air plenum free of visible dust or debris?

11.     Do filters fit properly and are they the proper efficiency as recommended by the HVAC system manufacturer?

12.     Is the supply air plenum (directly downstream of the air handling unit) free of moisture stains and contaminants?

Metal Ducts

13.     Are interior ductwork surfaces free of visible debris? (Select several sites at random in both the return and supply sides of the system.)

Fiber Glass

14.     Is all fiber glass material in good condition (free of tears and abrasions and; well adhered to the underlying materials)?

Access Doors

15.     Are newly installed access doors in sheet metal ducts attached with more than just duct tape (e.g., screws, rivets, mastic, etc.)?

16.     With the system running, is air leakage through access doors or covers very slight or non-existent?

Air Vents

17.     Have all registers, grilles and diffusers been firmly reattached to the walls, floors and/or ceilings?

18.     Are the registers, grilles and diffusers visibly clean?

System Operation

19.     Does the system function properly in both the heating and cooling modes after cleaning?

So there you are, a few consumer protection measures of can take to be sure you get your money’s worth. But if you still have doubts about this issue, we’d be happy to provide some advice. Please give us a call at (323) 655-6126 or use our online form to schedule a check-up on your system.

Do you have other questions that you’re eager to get a response on? You’re at the right place! Fill out the form on our Ask an Expert page, and the resident expert at GAMA Air will get back to you quickly with an answer.

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