Learn why you should consider having your ducts cleaned.

Being out of sight, the interior of duct systems is also out of mind. Tens of millions of people around the world live and work in structures with mechanical heating, ventilation, and air conditioning (HVAC) systems that are designed to provide air at comfortable temperature and humidity levels, free of harmful concentrations of air pollutants.

Indoor air pollution is one risk that you can do something about.

Biological pollutants are living organisms. Two conditions are essential to spawn active biological growth:nutrientsandmoisture. Dust in duct systems, being organic, is an ideal nutrient source. And duct systems inherently have various areas where moisturemay occur to create microbiological amplification sites; cooling coils, condensate collectors, humidification devices, sections of ductwork with improperly installed or damaged insulation (either internal or external) allowing the formation of condensation when warm moist air comes in contact with cool duct surfaces. An inefficient system can allow moisture to “sheet” off the coil and enter the air stream instead of properly draining into the condensate collector. This “sheeting” will moisten or out-right soak the internal fibrous glass insulation that is typically downstream from the coil chamber.

Many homeowners and building managers have become aware of the potential IAQ benefits of duct cleaning. However, before you contract duct cleaning, it is important to know that it is NOT a regulated service. Without professional specifications or guidelines, opportunistic contractors can take advantage of client naivete by performing a superficial cleaning. The National Air Duct Cleaners Association (NADCA)* provides standards and guidelines for the industry. NADCA also created and administers an examination that certifies individuals, who pass, as Air Systems Cleaning Specialists (ASCS).
Many duct cleaning companies are either unaware of or ignore the findings of an Environmental Protection Agency (EPA) study on duct cleanings’ effectiveness.

The salient point in the EPA published report, based upon scientific data, bluntly states,“ . . brushing is necessary to effectively clean the (duct) surfaces.”(EPA-600/R-97137). Yet many companies do not use brushes in their process.

Americlean Services Corporation (ASC) is a certified member of NADCA with several NADCA certified Air System Cleaning Specialists (ASCS) on staff. Our process for both residential and commercial applications, utilizes mechanically powered brushes in conjunction with high pressure air devices. However, by definition, “duct cleaning” is simply that, cleaning “ducts”. The literal definition does not include; registers, diffusers, grilles, louvers, boots, turning vanes, dampers, plenums, mixing chambers, return air chambers, air handlers, supply fans, coils, condensate collectors, filter racks, distribution boxes, or any other devices that are part of the HVAC duct system through which air passes. The National Air Duct Cleaners Association realized this misnomer. In the creation of their standard 01 – 92, “Mechanical Cleaning of Non-Porus Air Conveyance System Components” they succinctly define a professional Scope of Work for “duct cleaning.”

Air Conveyance System (ACS): The air conveyance system is any interior surface of a building's air distribution system for conditioned spaces and/or occupied zones (See ASHRAE 62 -–1989). This includes the entire air moving system from the points that the air enters the system to the points where the air is discharged from the system. The return air grilles, air ducts, (except ceiling plenums) to the air handling unit (AHU), the interior surface of the AHU, mixing box, coil compartment, condensate drain pan, humidifiers and dehumidifiers, supply air ducts, fans, fan housings, fan blades, air wash systems, spray eliminators, turning vanes, filters, filter housings, reheat coils, and supply diffusers are all considered part of the ACS.

HVAC systems naturally accumulate particulate matter over extended periods of time, not overnight. Proportionally, as the accrual of debris increases, the quality of the air decreases. If ignored and not maintained this accumulated melange of dust will cause a transgression of the system’s designed efficiency. Decreased air movement, or ventilation, is another contributor to poor Indoor Air Quality.

HVAC systems naturally accumulate particulate matter over extended periods of time, not overnight. Proportionally, as the accrual of debris increases, the quality of the air decreases. If ignored and not maintained this accumulated melange of dust will cause a transgression of the system’s designed efficiency. Decreased air movement, or ventilation, is another contributor to poor Indoor Air Quality.

Common indoor dust is composed of separate, distinct particles which are predominantly organic matter such as; fungi and bacteria spores (seeds), dust mites, insect body parts, human and animal dander and hair; all of which accumulate in HVAC duct systems. As a collection site for these biological contaminants, an HVAC system, over time, becomes an ideal incubation environment, or fertile breeding ground, for active microbiological growths. These biological agents are known to cause three types of diseases:

Hypersensitivity: Allergic reactions happen after a person is exposed, overtime, to molds, mildew, fungal spores, pollen, dust mites, and other organic matter. When inhaled, the bodies of some people treat these as foreign invaders, producing hay fever-like symptoms and asthma.

Infections: A classification of spores from specific microbes, called pathogens cause known diseases, some of which are fatal.

Toxicosis:Some microbiological growths in either the growth or decay stages produce chemical toxins causing sickness or death.




Moisture mixed with ambient duct dust equals a probable microbiological IAQ problem. And worst of all it is not openly visible and evident as a source of contamination. Remember, duct systems are out of sight and out of mind.

* National Air Duct Cleaners Association (NADCA) 815 K Street, N.W., Suite 503, Washington, D.C. 20005, 202-737-2926

The Duct Cleaning Process 1. An access opening is created in the plenum, or in the main duct line next to the furnace. 2. Highly trained, experienced technicians connect the hose from a HEPA filtered high velocity vacuum to the access opening next to the furnace. 3. Each register on the wall, floor, and ceiling is carefully removed and cleaned using a hand held HEPA filtered vacuum. (The EPA and NADCA contend that it is impossible to clean a duct system without removing all the registers) 4. Vent openings are temporarily sealed off to eliminate the threat of dust in the home and to concentrate the vacuum's negative air pressure.

5. An electric rotary brush is used to dislodge the contaminants accumulated on the inner duct surface. (An EPA report, based upon scientific data, bluntly states, “ . . brushing is necessary to effectively clean the (duct) surfaces.” EPA-600/R-97-137. Yet many companies do not use brushes in their process.) 6. An air-washing device is inserted to push the remaining debris toward the vacuum. 7. The fan blower compartment, plenum and coil are cleaned with high pressure air and vacuumed.

8. A pre-cut sheet metal plate is screwed in place and sealed with metal tape on the access opening previously made. 9. Finally, through our ductscope or fiber optic video camera, we re-inspect the air duct system in order to verify its cleanliness. During, and after, the cleaning process, we encourage you to see for yourself the cleanliness of your air ducts.

IS THIS A DUSTY PROCESS?

No. Americlean's vacuums use HEPA filters to insure that 99.97% of particulate matter is contained within the vacuum.

IS CUTTING A HOLE NEEDED?

Yes. It is the only way to capture the debris before it reaches the furnace and its delicate components. Access openings are standard practice in the industry.

IS BRUSHING NECESSARY?

Yes. Americlean's patented electric rotary brushes are long and flexible enough to clean any duct configuration. Chimney sweep brushes cannot do the job. Vacuuming alone removes only 40% of the debris. No matter how powerful the machine is, only internal agitation will remove the remaining contaminants. An EPA study (EPA-600/R-97-137) said: "brushing is necessary to effectively clean the duct..."

IS SANITIZING A GOOD IDEA?

Many clients ask about the application of a santizing chemical as a normal function while cleaning ductwork. And some duct cleaning contractors routinely offer sanitizing for free. If microbial growth is suspected in a duct system, Americlean recommends a micro-biologist perform testing. The application of a sanitizing agent is not recommended as a general practice unless microbial growth is visually evident or a professional biological assessment has been performed. Sanitizing agents applied to the interior of a duct system must be registered with the EPA because these chemicals are classified as pesticides (toxic chemicals). Dust in a duct system consists predominantely of organic based matter. This is a nutrient source for biological growth and sustenance. If the food source is removed by professional cleaning methods the application of a sanitizer as a precautionary measure is redundant. Virginia, Maryland, Washington D.C., Northern Virginia, Fairfax, Arlington, Alexandria, Mclean, Tyson's Corner, Sterling, Dulles, Ashburn, Herndon, Woodbridge, Manassas, Centreville, Haymarket, Leesburg, Winchester, Front Royal, Annandale, Merrifield, Quantico, Stafford, Warrenton, Prince William, Columbia, MD, DC,  VA