FAQ - Frequently Asked Questions

Duct Cleaning - Frequently Asked Questions

The techniques to perform Air Duct Cleaning are accomplished by following an organized specification specific to a particular HVAC system. Often the method of cleaning is determined based on the accessibility to the inside of the ductwork. Access to the ductwork may be limited because of a solid ceiling, cement floor or old acoustical tiles. There may be an issue with reaching ductwork due to it's being high up off of the ground or in a difficult to access place. We may also find obstacles that need to be addressed and worked around. They may include, sheet metal screws, air flow dampers, turning vanes, reheat coils, fire dampers, fire probes, thermostats. Therefore the equipment that we choose to use may be a combination of various tools, hepa vacuums, pneumatic brushes and air compression to get the desired results for the job.

In the commercial environment it is going to depend upon many factors affecting the building. Is there high usage of the space? What is the space used for? What is the desired level of cleanliness for the space? All of these questions and more should be discussed and a plan can be implemented to best suit the needs for the specific facility. Some homeowners who are sensitive to their indoor environment have us clean their ductwork annually. Most people should have the ductwork in their home cleaned every three years.
NADCA stands for the National Air Duct Cleaners Association, which is a nonprofit trade association that serves the HVAC inspection, cleaning, and restoration association. Founded in 1989, NADCA has more than 1,200 member companies from more than 20 countries, and is the focal point of the global industry. Duct & Vent Cleaning of America, Inc. joined NADCA in February of 1990, only several months after the company and association were both founded.

NADCA sets the standards for air duct cleaning companies. It is required that all members have one staff member who is a certified Air Systems Cleaning Specialist (ASCS).  Its members have signed a Code of Ethics, and they have invested time and resources in training and educating its employees. Members must participate in continuing education and take regular recertification exams. In addition, NADCA members must meet specific insurance requirements. Lastly, cleaning and restoration of your heating and cooling system must be done in accordance to NADCA standards. The current standard, ACR 2021 can be found by clicking here.

Duct & Vent has been a member in good standing since they joined NADCA in February of 1990. In fact, the company’s president Michael Vinick was named the board president of NADCA at the 2015 and 2016 Annual Meetings, and has been an active member of NADCA since his company first joined the association. He has been a board member since 2008, and has also served as the northeast regional coordinator (1995-1998), membership chair (2008-2014), board treasurer (2011-2012), 2nd vice president (2013), and 1st vice president (2014). 

<strong>Michael Vinick at the 2016 NADCA Annual Meeting</strong>
Michael Vinick at the 2016 NADCA Annual Meeting

Duct & Vent Cleaning of America, Inc.  exceeds NADCA required certifications. We have multiple people who are ASCS certified, multiple safety certifications, and have been a consistent NADCA outstanding safety award winner from 2001-2015.  Duct & Vent Cleaning of America, Inc.  conducts weekly safety employee information meetings.  We have continual service personnel assessment and development procedures in place to ensure you are receiving the best services in our industry.

You can see our membership verification by clicking here.




It is the most current internationally recognized assessment, cleaning, and restoration standard for HVAC systems.  Standards are in place for:

  • Assessing new and existing HVAC systems.
  • Evaluating the cleanliness of HVAC system components.
  • Determining the need to clean, and cleaning and restoring systems to a verifiable cleanliness level.
  • Preventing job-related hazards.

To read the latest ACR 2021 NADCA standard, please click here.

Access: The ability to gain entry to the interior of the air duct or HVAC component.

Access Door: Fabricated metal barrier (hatch) by which a service opening is accessed or closed.

Adhered Substance: A material, such as mastic, that is not removable by direct contact vacuuming.

ACGIH: American Conference of Governmental Industrial Hygienists.

Adhered Particulate: Any material not intended or designed to be present in an HVAC system, and which must be dislodged in order to be removed.

Aerosols: Solid or liquid airborne particles.

AIHA: American Industrial Hygiene Association.

Air Duct: A passageway for distribution and extraction of air, excluding plenums not installed in accordance with SMACNA Standards (See ASHRAE Terminology of Heating, Ventilation, Air Conditioning & Refrigeration, 1991).

Air Duct Covering: Materials such as insulation and banding used to cover the external surface of a duct.

Air Duct Lining: Generally refers to fiberglass or other matting affixed to the interior surfaces of the air ducts for thermal insulation and noise attenuation.

Air Filtration Device (AFD): A portable or transportable, self-contained blower assembly designed to move a defined volume of air equipped with one or more stages of particulate filtration. Depending on the mode of use, an AFD that filters (usually HEPA) and re-circulates air is referred to as an "air scrubber." One that filters air and creates negative pressure is referred to as a "negative air machine."

Air-handling Unit (AHU): A packaged assembly, usually connected to ductwork, that moves air and may also clean and condition the air.

Coils: Devices inside an HVAC system that temper and/or dehumidify the air handled by the HVAC system. These include heat exchangers with or without extended surfaces through which water, ethylene glycol solution, brine, volatile refrigerant, or steam is circulated for the purpose of total cooling (sensible cooling plus latent cooling) or sensible heating of a forced-circulation air stream.

Collection Device: A HEPA-filtered machine designed primarily to collect debris, filter particulate and discharge air back to the indoor environment, or a fan driven non-HEPA-filtered machine that is designed to collect debris, and then filter particulate while discharging the air outside the building envelope.

Ductwork: A system of passageways for distribution and extraction of air, excluding plenums not installed in accordance with SMACNA Standards.

EPA: United States Environmental Protection Agency

Duct Access Door: Fabricated metal barrier (hatch) by which a service opening is accessed or closed.

HEPA: High Efficiency Particulate Air. To be called a true HEPA filter, or certified HEPA filter the filter must have a documented filtration efficiency of 99.97% at 0.3 micron-sized particles.

HVAC System: The heating, ventilation, and air conditioning (HVAC) system includes any interior surface of the facility's air distribution system for conditioned spaces and/or occupied zones. This includes the entire heating, air-conditioning, and ventilation system from the points where the air enters the system to the points where the air is discharged from the system.

IAQA: Indoor Air Quality Association

Mold Contaminated: The presence of indoor mold growth and/or mold spores, whose identity, location and amplification are not reflective of a normal fungal ecology for an indoor environment, and which may produce adverse health effects and cause damage to materials, and adversely affect the operation or function of building systems.

Porous HVAC System Surface: Any surface of the HVAC system in contact with the air stream that is capable of penetration by either water or air. Examples include fiberglass duct liner, fiber glass duct board, wood, and concrete.

Thermal Acoustic Materials: HVAC insulation materials designed for sound and temperature control.

UL: Underwriters Laboratories, Inc.

Vacuum Collection Equipment: See "Collection Device."

Visibly Clean: A condition in which the interior surfaces of the HVAC system are free of non-adhered substances and debris.

Visual Inspection: Visual examination with the naked eye of the cleanliness of the HVAC system.

Wet Process Cleaning: Any method of mechanical cleaning of HVAC components that utilizes water and/or liquid chemicals as part of the process (i.e. power washing, steam cleaning, hand washing).

Human Health Concerns, Energy Management and Indoor Environmental concerns will be addressed. Utility bills can be lowered Allergy & Asthma sufferers can be helped. Indoor cleaning can be reduced Remove unwanted indoor pollutants; mold, fungus, bacteria and mites

Can the company show proof of NADCA membership and certification? How long has the Duct Cleaner been in the HVAC system / Air Duct Cleaning business? Can the Duct Cleaner provide you with evidence of the current Worker’s Compensation and General Liability Insurance coverage? Can the Duct Cleaner assure you that their staff has had criminal background checks and pre-employment drug testing program? Does the Duct Cleaner possess the proper licenses and business registrations that are required by your city or state to perform the work they are proposing? Does the Duct Cleaner ensure that all of their field staff have OSHA 10 Hour Safety Training Certification? Can the Duct Cleaner provide you with 3 to 5 customer references with phone numbers for projects of similar size and scope of work which they provided service in the last year? Does the Duct Cleaner have written safety, respiratory, and confined space programs in addition to OSHA compliance reports? Will the Duct Cleaner provide you with a means to conduct a visual inspection at any time during the cleaning? (Mirror and flashlight, camera or other remote visual systems) Will the Duct Cleaning company actually do the work? (Some companies subcontract the work to independent contractors. You will want to apply these guidelines for subcontractors as well.)

According to NADCA, up to 40 pounds of dust is created annually through everyday living in a typical six-room house. Other contaminants and air pollutants such as dander, dust, and chemicals are also generated by normal occupation in a home. Did you know that these contaminants end up in your HVAC system and are re-circulated on average of 5-7 times per day? Over time, these contaminants can be found in your duct work. Those who suffer from autoimmune disorders or respiratory health conditions such as asthma will benefit by breathing cleaner air. Your indoor air quality will improve, and you will feel healthier.
• Can the company show proof of NADCA membership and certification? • Can the Duct Cleaner provide you with assurances that their duct cleaners have had criminal background checks and drug testing? • Will the contractor conduct a thorough inspection of your system at the commencement of performing any work and alert you to any problems? This is required by the current NADCA ACR Standard. • Is the HVAC system fully operational prior to cleaning? • Clean All Supply Air Ductwork • Clean All Return Air Ductwork • Will the contractor provide you with the opportunity to visually inspect their work prior to closing the ductwork upon completion of their work?