Letter from the President

Air Duct System Cleaning and Sanitizing Process 

The HVAC system should be mechanically cleaned and sanitized with an EPA (Environmental Protection Agency) registered fungicidal prior to clearance testing. This process should be conducted by a technician qualified under the standards of the National Air Duct Cleaners Association.

Step 1: System Cleaning

1. An 8 to 12 inch hole should be cut in the supply side of your system, more specifically into the main duct. Then attach a large hose from the furnace to your vacuum which then supports negative suction needed to properly clean the system. THIS NEGATIVE SUCTION HELPS TO ASSURE NO DIRT AND DEBRIS WILL ENTER THE HOME. Once the vacuum is turned on, the suction will immediately start removing the loose contaminated debris from the system.

2. All of the vents in the building should be closed off to increase the centralized suction. The technician should also insert foam blocks into the furnace, sectioning off the supply side from the return side. This is an effort to further centralize suction to stop any debris from falling into the heating and cooling elements.

3. At each vent in the main duct 3 types of cleaning methods can take place. They include:

1. Rotary Brush System- A nylon bristled brush is attached to a long plastic covered cable which is attached to a power drill. As the drill is operated the cable is fed into the vent and the bristles rotate, loosening ALL contaminants from the interior duct. The duct size will determine the brush size to be used in the process.

2. Forward Air Wash System- A small plastic attachment used in conjunction with an air hose. It is powered by an air compressor which is set up outside. The air hose is moved forward into the vent as the air forces the debris into the main duct.

3. Reverse Air Wash System- Very similar to the forward air wash system. However, instead of forcing the contaminated debris forward, the reverse air wash system forces contaminants in the opposite direction of the air hose (i.e. if the air hose faces North, the contaminants are forced south).

4. At the main duct which is usually located in the basement, attic, or crawl space, sizable openings are made to further clean the interior duct. This area is where all the large material tends to settle.  

5. Steps 2 through 4 will then be repeated on the return side of the system. 

6. All openings made by the duct cleaning company should be sealed with larger pieces of sheet metal, sheet metal screws and high grade foil tape made especially for this purpose. All openings are standard within the industry and assure a proper cleaning.  Each vent is removed and individually cleaned.  

Step 2: Cleaning the Air Handling Unit (AHU) 

1. The blower assembly (fan) should be removed from the system and broken down into three components to include the motor, the housing and the blades. Each component is cleaned separately outside using rags, brushes, cleaning solutions and compressed air.

2. The blower compartment must be thoroughly vacuumed.

3. Once cleaned, the assembly will be returned to its original working condition.

Step 3: Deodorizing and/or Sanitizing

While the vacuum is still attached to the supply side of the duct system the technician should fog a fine mist of EPA registered disinfectant and deodorizer such as OXINE. Oxine acts to kill mold, mildew, bacteria and fungi that may be present in the duct system. Eliminating the previously named contaminated debris from the interior duct system should effectively aid persons affected by upper respiratory problems, including allergies and asthma.  

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