Air Duct Cleaning Methods Explained

Air duct cleaning services have been available since the 1900’s.  Over the years there have been numerous changes in technologies and industry standards.  Air duct cleaning method advancements have improved the quality and safety of the air duct cleaning process.  Before agreeing to clean your air ducts, you should learn about the different air duct cleaning methods.

Source Removal

Source removal is the recommended air duct cleaning method.  Source Removal, is the mechanical cleaning of system components to remove dirt and debris.  Dust and other particle debris tend to stick or statically cling to the interior of air ducts.  Source removal requires two key elements:

Mechanical agitation:

which loosens the debris from the walls of the air ducts and HVAC components.


which safely removes the debris from the HVAC system to levels that are acceptable to industry standard.

Air Duct Cleaning Methods

Steam Air Duct Cleaning:

Steam Air Duct Cleaning methods utilize a wand that delivers a high temperature & high pressure steam to agitate the debris from the walls of the air ducts as the air ducts are drawn into negative pressure by a vacuum.

Steam cleaning and other methods involving moisture should not be used on any kind of duct work.  Modern HVAC components are highly dependent on electronic components to make them efficient; the introduction of moisture will damage system components.

Truck Mounted Vacuum Cleaning:

Truck mounted vacuum methods utilize a vacuum that is powered through the PTO shaft of an operating vehicle.  Truck mounted vacuum cleaning technology is based on the volume of air being drawn.  The truck mounted vacuum draws a volume of air typically ranging between 10,000 to 15,000 cubic feet of air per minute.  A vacuum hose is attached from the truck to the trunk lines of the ventilation system.  As the ventilation system is drawn into a vacuum, either rotary brushes or air lines are inserted into air vent registers to agitate debris to the collection point.

While once a widely used air duct cleaning method, industry professionals are veering away from a truck mounted and gas powered vacuums because of the high probability of cross contamination.  Truck mounted vacuums draw vehicle exhaust and debris into the ambient air while in operation.

Point of Contact Air Duct Cleaning:

Point of contact methods are currently the safest and most effective air duct cleaning method.  A point of contact air duct cleaning method utilizes a portable HEPA filtered vacuum and an agitation device to simultaneously to clean the air ducts.  Portable HEPA vacuum cleaning technology is based on the velocity of air being drawn.  High velocity of vacuum allows for greater lift of the debris, and the HEPA filter prevents the potential of cross contamination.

Though point of contact air duct cleaning methods are currently the safest and most effective means of cleaning air ducts, new and innovative air duct cleaning technologies are always in development.

Air Duct Cleaning Tools

Qualified air duct cleaning contractors employ a variety of different power, pneumatic and hand tools when cleaning air ducts.  While there are numerous types of equipment used in the air duct cleaning industry, the job site to a large extent, defines what air duct cleaning tools will be used.

Breaking Contaminants Loose

Properly cleaning HVAC systems requires removing the sources of contamination from the walls of the air ducts.  Just as there are numerous types and sizes of air ducts, they are numerous air duct cleaning tools used to loosen debris from the walls of the air ducts.

  • Mechanical Agitation: Mechanical air duct cleaning tools are typically brushes powered through an electric motor, and are generally used for sheet metal air ducts.  Mechanical air duct cleaning tools are primarily used for more aggressive cleaning applications.
  • Pneumatic Agitation: Pneumatic air duct cleaning tools utilize compressed air to agitate debris from the walls of the air ducts.  There are numerous pneumatic air duct cleaning tools that can be used such as air whips, compressed air nozzles, or skipper balls.  Pneumatic air duct cleaning tools are primarily used to clean sensitive materials such as internally lined fiberglass air ducts, fiberglass duct board, and flex line air ducts.
  • Hand-brush & Contact Vacuuming: When accessible, hand brushing and contact vacuuming with a HEPA filtered hand vacuum is always the most effective method of cleaning.

Collection of Contaminants

A vacuum is the most commonly used air duct cleaning tool in the air duct cleaning industry.  The most important consideration for every ventilation cleaning project is the prevention of cross contamination. During air duct cleaning, the entire HVAC system is placed under negative pressure (vacuum) to collect loosened debris and prevent the spread of contaminants.  There are two main types of collection devices:

  • Truck Mounted Vacuums: Truck Mounted Vacuums are gas powered vacuums that are powered through the PTO of an operating vehicle.  The amount of vacuum typically ranges from 10,000 – 15,000 cfm.  Because of the high volume of air the Truck Mounted Vacuum draws, they have a high propensity for drawing vehicle exhaust and contaminants within the workspace.
  • Portable HEPA filtered Vacuums: In most instances, portable HEPA filtered vacuums are the most effective vacuum collection device.  HEPA filtered vacuums have a high velocity of vacuum draw allowing for greater lift of the debris and can often be brought to the contaminant source.  HEPA filters prevent contaminants from being dispersed from the vacuum exhaust and prevent the potential of cross contamination.