Why the Ducted Heating and cooling ducts

needs to be cleaned:

Maintaining clean ducted heating and cooling ducts is an important part of sustaining acceptable indoor air quality. When a heating and cooling system is a source of contaminants introduced into engaged spaces, properly performed system cleaning services should take place to lessen or remove contaminant introduction.

Contaminants in the systems may take many forms. Common contaminants include dust particles, lively bacterial or fungal development, and debris from rusted system components, man-made vitreous fibers, mold spores, and other items.

Some of common contaminants in the ducted system

Experience has shown that very few (if any) ducted systems are free of all particulate. In fact, particle deposition on component surfaces starts before the system is even installed. Airborne particles in factory settings and assembly areas are likely to settle on air-handling components and fiber glass insulation, as well as stick to the surface of metal components.

The original installation process will subject the system to even more contamination. Building sites contain a significant amount of airborne concrete dust, plaster dust, sand particles, biological particulate aerosols and many other airborne contaminants in the air. These particles often inhabit on or inside the system during construction.

After the ducted system is installed and its function begins, the particulate buildup process continues throughout the life of the system. Poor design, installation and maintenance practices, low-efficiency air filtration, air flow bypass, inadequate or intermittent preventative maintenance

Practices, humid conditions, and many other factors will result in contaminated systems. Ducted systems may also serve to convey and re-allocate unwanted particles from other sources in the building.

Ducted systems should be regularly inspected for cleanliness by visual means.

The need for more regular cleanliness inspections is subject to many environmental, mechanical and human factors. Geographic regions with climates having elevated humidity, for example, will necessitate heating and cooling system inspections on a more regular basis, due to the increased potential for microbial amplification.

If the inspection of a ducted unit’s air-handling apparatus reveals contamination, then supply and return ductwork must be inspected during that same time.  

Visual inspection for cleanliness should be included as part of the ducted heating and cooling preventive maintenance schedule and should include all components of the system. The necessary frequency of inspection will vary depending on building use, occupant load, environmental location, and adjacent environment. In general, most systems should be inspected annually for cleanliness.

Conditions Requiring Cleaning

It is highly suggested heating and cooling system cleaning be performed when any of the following conditions are found during the Systems Cleanliness Inspection.

System Contamination

If significant buildup of contaminants or debris is visually observed within the ducted system, then cleaning is necessary. Similarly, if confirmation of active fungal colonization is visually observed or established by diagnostic methods, then cleaning is required.

If the system discharges visible particulate into the occupied space, or a contribution of airborne particles from the system into the indoor air is confirmed, then cleaning is extremely recommended.

Compromised Performance

Cleaning is highly recommended for heat exchange coils, cooling coils, air flow control devices, filtration devices, and air-handling equipment determined to have restrictions, blockages, or contamination deposits that may cause system performance inefficiencies, air flow deprivation that may significantly affect the design intent of the system.

Indoor Air Quality Management

Indoor air quality management plans that include sporadic cleaning and maintenance are highly recommended to minimize recurring contamination within ducted systems. It is highly recommended that particular thought be given to buildings or residences with sensitive populations such as individuals with compromised immune systems, and particular environment or buildings with sensitive building contents or critical processes.

Ducted Heating and Cooling System Cleaning

The system includes all core surfaces of the facility’s air distribution system that service conditioned spaces and/or occupied zones. This includes the entire heating, air-conditioning and ventilation system from the points where air enters the system, to the final point of discharge prior to entering the conditioned environment. The return air grilles, return air ducts to the AHU, the interior surfaces of the AHU, mixing boxes, coil compartment, condensate drain pans, humidifiers and dehumidifiers, supply air ducts, fans, fan housings, fan blades, air wash systems, spray eliminators, turning vanes, filters, filter housings, reheat coils, flexible ductwork and supply diffusers are all considered part of the system. The system may also include other components such as dedicated exhaust and ventilation components and make-up air systems.

Environmental Engineering Controls

To the extent feasible, engineering controls must be used to assure worker safety and health, and to prevent cross-contamination. These engineering controls may include, but are not limited to source control, isolation barriers, pressure differentials, dust suppression methods, HEPA vacuuming and filtration, detailed cleaning, temperature and humidity control, and a hygienic approach.

Duct Pressurization

Heating and cooling ducts must be kept at an suitable pressure differential relative to adjacent indoor occupant spaces during all cleaning procedures and as may be required during assessment activities. It is highly recommended pressure differential be achieved through the use of a negative air machine or HEPA filtered vacuum collection equipment.

Pressurization differential requirement applies to projects taking place within all building use classifications. It must be possible to demonstrate and document pressurization differential procedures.

Power Washing, Steam Cleaning and Wet Cleaning

Power washing, steam cleaning, or any other form of wet process cleaning of the system components must not damage the components. It is highly recommended that cleaning agents or water not be applied to porous system components.  

Cleaning the Duct Systems

Duct systems must be cleaned to remove all visible contaminants and be capable of passing cleanliness verification tests. Inaccessible areas must be accessed by service openings constructed in the system that are large enough to accommodate mechanical cleaning procedures.

Mechanical Cleaning Method

When cleaning ducted heating and cooling systems using mechanical cleaning methods designed to dislodge and remove contaminants from within the system components.

We, Dust Busters Australia, will clean your entire air duct system, not just the portions that you can see, or that are obvious. We know that even a single contaminated component can result in re-contamination of the entire system, thus negation any and all benefits of the duct cleaning. We use specialized air duct cleaning tools to dislodge dirt and other debris in ducts, then vacuum them out with a high-powered vacuum cleaner, and also provide hand cleaning and sanitizing.

Our new technical computerized ducted heating and cooling cleaning equipment can do the accurate cleaning job to a high standard. One of the amazing things is that all the cleaning operation can be monitored by computerized control system on the display screen.