National Air Duct Cleaners Association (NADCA) Practice Test

These questions are part of the practice quiz. Start practicing

• Which NADCA standard is most closely associated with HVAC system assessment, cleaning, and restoration?
• What is typically the first step in NADCA-style inspections?
• How should damp or wet ducts be handled during an assessment?
• What type of evidence is commonly used to verify interior cleanliness after duct cleaning?
• What is a hallmark of NADCA-certified professionals?
• Which of the following is typically included in HVAC inspections?
• To help define the scope of work for HVAC cleaning, which document is typically used?
• Biocides or oxidizers in duct cleaning are appropriate...
• Which set of components is commonly included in an NADCA HVAC system assessment?
• Which component is explicitly listed as part of the AHU cleanliness inspection?
• What should post-cleaning verification consist of?
• What verification methods are commonly used after cleaning to confirm cleanliness?
• How do duct size and air velocity influence cleaning technique?
• Which condensate-related parts are included in the AHU cleanliness inspection?
• What factors influence the decision to perform duct cleaning?
• What is the purpose of borescope verification in post-cleaning?
• Which item should be included in the scope of work regarding cleaning?
• Routine HVAC Inspection is:
• Containment during duct cleaning is intended to...
• Which mil thickness is specified for containment barriers' fire retardant polyethylene sheeting?
• What is the appropriate approach to coil cleaning when determining if it is required?
• An area of the HVAC system in contact with the air stream capable of penetration by either water or air is known as
• Turning vanes are rarely found in which type of system?
• Name a primary equipment type used to maintain negative pressure during cleaning?
• A fresh air intake provides air to which part of the system?
• What is the primary purpose of service openings and access doors during duct cleaning?
• What is a typical recommended maintenance interval for duct cleaning in residential settings?
• Which deodorizing practice aligns with NADCA guidance?
• What should be included in a client-facing service report?
• Beyond the immediate service, what should the client report include to support ongoing system care?
• Which item is not typically included in AHU cleanliness inspections?
• Which statement correctly identifies a coil-related component included in the AHU inspection?
• What considerations are unique to cleaning ductboard (fiberglass) ducts compared with sheet metal ducts?
• Which option best represents a cross-contamination prevention measure?
• What is the recommended approach if residual dirt remains after cleaning?
• Which statement best describes the status of engineering controls on HVAC cleaning projects?
• Which PPE combination is commonly required for duct cleaning work?
• A project requires chemical application within an HVAC system. What are the possible risks associated with chemical products?
• Under what circumstances should a duct cleaning project be deferred or stopped?
• Which elements are typically included in a NADCA system map?
• What is a post-cleaning verification report and what should it include?
• Information collected from an HVAC inspection shall be
• In a commercial project, power washing equipment can be used for cleaning ______.
• What type of ductwork is made with asbestos?
• How does NADCA define cleaning versus restoration?
• What items are typically documented in a NADCA cleaning report?
• How should consumer-grade tools be treated in professional duct cleaning work?
• What is the importance of a customer-facing cleaning report?
• What is the purpose of containment setup during cleaning?
• Which statement best captures the purpose of a pre-cleaning survey?
• Which HVAC components are commonly targeted for cleaning under NADCA guidelines?
• What should be done if a duct system shows leaks during cleaning?
• What is the purpose of post-cleaning verification?
• Which of the following is commonly included in an NADCA HVAC assessment?
• How do cleaning and sanitizing differ in HVAC systems?
• How should a NADCA professional respond if mold growth is observed inside the duct system?
• Where should documentation from a duct cleaning project be retained and shared?
• How should a NADCA-certified technician handle disputes about scope or charges?
• Why is client sign-off on the scope and results important?
• What is the purpose of using negative air machines with HEPA filtration during cleaning?
• Which types of debris are commonly found in ducts and considered contaminants?
• How should moisture be managed when performing wet cleaning of ducts to avoid mold growth?
• What is static pressure and why is it relevant to duct cleaning?
• Why is excessive internal pressure during cleaning potentially harmful?
• The purpose of a damper in an HVAC system is to adjust:
• Mold contamination conditions reaching Condition 2 or 3 indicate cleaning is necessary.
• A high efficiency gas furnace was in use during a home renovation project. HVAC system cleaning is required if which of the following is found?
• Which of the following is a key safety requirement to protect occupants during duct cleaning?
• After cleaning, service openings and access doors should be?
• If mold remediation is performed according to ANSI/IICRC Standard S520, what is required for HVAC components?
• During and after HVAC cleaning, NADCA recommends what minimum number of air changes per hour?
• What types of documentation are commonly collected to verify containment and cleanliness after duct cleaning?
• Which statement best describes the scope of cleaning typically performed during a standard duct cleaning service?
• In NADCA terms, which statement describes the difference between the duct cleaning and system cleaning?
• If a building has 20 units, how many should be inspected during a routine HVAC system inspection?
• How is the effectiveness of coil cleaning measured?
• Bioaerosols are defined as:
• What is the purpose of maintaining negative pressure in the duct cleaning work area?
• Turning vanes are rarely found in which type of system?
• According to NADCA, the NADCA standard level 1 containment requires:
• If thermal lining or fiberboard has become water soaked, what is the recommended action?
• What is 'dirt loading' and how is it used in planning a cleaning project?
• Which practice is recommended as a condition to achieve LEED certification for a building?
• How should duct cleaning projects be coordinated with other trades?
• Which practice helps prevent debris leakage and cross-contamination during duct cleaning?
• What types of PPE are commonly required for duct cleaning work?
• What is a typical indicator that the AHU interior requires cleaning?
• If asbestos-containing material is suspected in ductwork, what is the appropriate course of action?
• Access openings should be removed to minimize damage by following which practice?
• What is a common post-cleaning verification method used by NADCA professionals?
• Turning vanes are used to
• Which sealing element around closures is included in AHU cleanliness inspection?
• If cleaning or coating will not restore fibrous glass materials, what is recommended?
• Why is lockout/tagout important in duct cleaning operations?
• What is the recommended handling of collected debris?
• If a dampener must be opened, what is the first step?
• What is the primary objective of the NADCA ACR Standard for assessment, cleaning, and restoration of HVAC systems?
• Which statement best describes dirt loading in planning a duct cleaning project?
• When is the time to perform an Inspection?
• NADCA recommends ambient air cleaning during and after HVAC cleaning. How many air changes (min) are recommended?
• During a typical duct cleaning service, which HVAC components are most commonly accessed and cleaned?
• What should verification include to demonstrate completion of cleaning?
• How does NADCA guidance inform chemical use in HVAC cleaning?
• What is the purpose of a decontamination or cleanup phase after cleaning?
• What is a consequence of using consumer-grade tools in professional duct cleaning work?
• Which statement best describes a proper verification outcome?
• What is the typical sequence of operations in a duct cleaning project?
• What is the primary purpose of containment and barriers during a duct cleaning project?
• How can a contractor minimize the risk of damaging ductwork or components during cleaning?
• What is the purpose of providing verification photos along with the written report after cleaning?
• What is the typical NADCA cleaning sequence?
• Which condition is a typical sign that a duct system may require cleaning beyond routine service?
• What is the typical role of a NADCA-certified technician during an inspection?
• Which system related to moisture is included in the AHU cleanliness inspection?
• What is the purpose of pre-cleaning documentation (photos, measurements, and system maps)?
• What is the role of photographs in the cleaning process?
• What is the purpose of a containment plan in the duct cleaning scope?
• What is the difference between cleaning ductwork and cleaning coil/air-handling components?
• If suspect microbial growth or other biological activity is identified in the HVAC system, it is recommended that
• Dislodged contaminants shall be captured with what?
• Which item is not explicitly listed as a NADCA-cleanable component in the provided scope?
• ANSI/ASHRAE/ACCA Standard 180 provides the Standard Practice for which topic?
• Why is a safety plan important in a duct cleaning project?
• Which NFPA standard addresses the installation of air-conditioning and ventilating systems?
• What does system mapping in NADCA assessment primarily involve?
• Which component is commonly associated with condensate management issues in HVAC systems?
• What is the purpose of air duct liner?
• The supply ductwork may need to be cleaned if:
• Which device should be used to capture dust during duct cleaning and prevent spread?
• Which training or credentials do NADCA members typically hold?
• On HVAC cleaning and restoration projects, the use of engineering controls is considered
• Is a single cleaning tool sufficient for all ducts?
• What is the purpose of post-cleaning verification in the NADCA sequence?
• HVAC system component cleaning is recommended when one or more conditions exist. Which of the following best reflects this guidance?
• To verify that a fiberglass duct has been installed correctly, which standard should be consulted?
• Containment's role during cleaning?
• What steps should be taken to minimize loosened fiberglass particles from being released into occupied space?
• How should coil cleaning be approached?
• Which statement about the Safety Data Sheet (SDS) is accurate?
• Which of the following has an adverse influence on a building's indoor environment when performing an inspection?
• On HVAC cleaning projects, the use of engineering controls is considered to be
• Which items are typically included in closing documentation for NADCA-compliant projects?
• If mold is observed, what sequence should a NADCA professional follow?
• What is the purpose of pre- and post-cleaning photos and measurements?
• Which item list describes elements that should be included in a scope-of-work document?
• Which factor would suggest duct cleaning may be necessary due to renovations or contamination history?
• The AHU cleanliness inspection includes which of the following coil components?
• Safety Data Sheet (SDS) is used for documenting
• Which tool is commonly used to visually inspect the interior of ducts without heavy disassembly?
• Which of the following best describes a post-cleaning verification report?
• What is the role of a HEPA-filtered vacuum in duct cleaning?
• Containment barriers should be built utilizing ______ mil fire retardant polyethylene sheeting or equivalent.
• Which of the following shall be included in a scope of work?
• Which type of insulation is explicitly listed as part of the AHU cleanliness inspection?
• How do dry cleaning and wet cleaning methods differ in HVAC duct work?
• Which factors influence the selection of cleaning tools (brushes, agitation devices, air whips) during duct cleaning?
• Which statement about engineering controls per NADCA/ACR is correct?
• Level 1 containment, as per NADCA, requires which pressure condition?
• Which surfaces are recommended to be vent cleaned in conjunction with mechanical methods?
• What filtration level is typically used on negative air machines?
• When you encounter inaccessible duct sections during an assessment, what is the recommended course of action?
• Which NADCA standard governs professional cleaning of HVAC systems?
• What is a negative air machine and what does it do?
• Which component used to control air flow is included in AHU cleanliness inspection?
• Which statement best describes when a duct cleaning project should be deferred or stopped due to moisture control?
• What is the proper method for storing and disposing of debris collected during duct cleaning?
• Which item is explicitly included in the AHU cleanliness inspection scope?
• Which standard should be referenced to determine the presence of fire-related particulate after a fire in a structure?
• How should contractors communicate limitations or residual dirt to clients?
• How should access openings (grilles/diffusers) be removed to minimize damage?
• Why is containment and negative pressure used during duct cleaning?
• Under what circumstance should the scope of work be revised?
• What indicates that cleaning is complete during verification?
• The inspection may cover which of the following unit components?
• What should be included in a pre-cleaning plan?
• How should a contractor verify that post-cleaning conditions meet client expectations?
• NADCA suggests mold remediation should be performed in accordance with which standard?
• Why is sealing HVAC components during cleaning important?
• In relation to noise control, which feature is inspected in the AHU?
• What is the required overlap for access panels to comply with NADCA standards?
• What is the role of quality control in NADCA cleaning projects?
• Which statement reflects a post-cleaning verification practice?
• Which of the following is NOT a typical use of a Safety Data Sheet (SDS)?
• What is the recommended method for cleaning a 2x2 foot diffuser when proper access is provided?
• If the inspector and or others may have been exposed to hazardous materials, what should be done?
• How should a cleaning crew address occupant comfort and noise during a project?
• Which cleaning consideration is particularly important for ductboard systems?
• Which item is NOT typically documented in a NADCA cleaning report?
• Why is it important to document access routes and containment entry/exit points?
• Should technicians rely on a single universal tool for every duct type?
• Which of the following should appear in an HVAC inspection report regarding cleaning?
• Service openings shall NOT
• A vertical cut can be used in the containment side wall which will provide access into the containment area if:
• What factor may require adjustments to the planned cleaning approach due to internal duct features?
• In the containment access, if a zipper is not available, what alternative access method is described?
• The AHU cleanliness inspection may include which evaporative technology component?
• Post-cleaning verification results should confirm which of the following?
• Why is routine maintenance important for maintaining duct cleanliness?
• Which standard guides mold remediation practices in NADCA guidelines?
• Which of the following may be used as supplementary verification after cleaning to confirm cleanliness?
• According to NADCA/ACR, a contaminant is defined as?
• How should occupants' safety be addressed when deodorizers are requested?
• What is a typical sign that a duct system may require cleaning beyond routine service?
• What action is required if moisture intrusion or visible mold is discovered inside ductwork?
• Which elements should be included in a formal duct cleaning quote?
• What safety precautions are necessary when working near electrical components inside an air handler?
• What type of building should have its HVAC system inspected every 2 years?
• What is the proper initial action when asbestos-containing insulation is encountered in ductwork?
• Which services are generally excluded from NADCA's HVAC cleaning scope?
• Given proper access which is the correct method for cleaning a 2x2 foot commercial diffuser?
• Which statement best describes post-cleaning verification documentation?
• Performing HVAC System Component Inspections Include:
• Which set of documents is essential to prove compliance with NADCA standards?
• What describes the tool-use approach for duct cleaning?
• What type of information should an HVAC inspection report include?
• Materials used in duct access doors shall be classified for flammability as determined by
• Which statement about dampers is true when performing maintenance safety?
• What is the primary purpose of capturing dislodged contaminants during HVAC cleaning?
• How should containment barriers be maintained to minimize cross-contamination during cleaning?
• Which statement about scope of work is accurate?
• HVAC Pre Inspection Is:
• Which of the following can be used to develop scope of work?
• Installation of access panels in an HVAC system which meets NADCA standards shall overlap the duct by?
• How should supply and return air be protected during cleaning?
• Which items should be protected in the environment around the work zone?
• What distinguishes visible contamination from hidden contamination in ducts?
• Which of the following relates to the air-moving components of an AHU in the cleanliness inspection?
• Which gasket-related element is part of AHU cleanliness inspection?
• How should mold or water damage discovered within ducts be addressed?
• Water in the condensate pan may indicate which problem?
• How does NADCA define a 'clean' system after cleaning?
• How should mastics or joint sealants found in ducts be treated during cleaning?
• Name two acceptable cleaning methods for metal ductwork?
• By policy, what action should be taken if moisture intrusion or visible mold is found inside ductwork?
• Which factor could prompt more frequent duct cleaning?
• Which organization provides standards for ductwork installation, including S180?
• Which of the following should be included in a scope of work?
• What type of information is typically included in the equipment list portion of a NADCA cleaning report?
• What are potential risks of using aggressive chemical cleaners in ducts?
• Is clothes dryer vent cleaning included within NADCA’s standard scope?