View Full NADCA ASCS Exam Dumps and Practice Test Dumps.

Question 61. What is the minimum containment level for HVAC cleaning projects

1. Level 3
2. Level 4
3. Level 1
4. No containment

Correct Answer: 3. Level 1

Explanation:

Level 1 containment is the minimum level of containment required for HVAC system component cleaning projects under NADCA guidance. It includes placing the system or work area under negative pressure, using protective coverings where necessary, maintaining cleaning tools and equipment properly, and controlling cross contamination. Containment helps prevent loosened dust and debris from escaping into occupied areas while cleaning is performed. More protective containment measures may be necessary when project conditions justify them, but Level 1 establishes the basic controls expected during ordinary HVAC cleaning activities.

Question 62. What additional feature distinguishes Level 2 containment

1. Temporary barriers
2. Higher refrigerant pressure
3. Larger filters
4. Permanent duct removal

Correct Answer: 1. Temporary barriers

Explanation:

Level 2 containment adds temporary barriers while also including the requirements established for Level 1 containment. These barriers provide greater separation between the work area and surrounding spaces when project conditions require additional contaminant control. The appropriate containment level should be based on the nature of the contamination, building occupancy, potential exposure, and project requirements. Containment is intended to prevent cleaning activities from creating a new indoor environmental problem. Technicians should establish the required controls before disturbing contaminants inside the HVAC system.

Question 63. What efficiency is required for HEPA filtration used by indoor exhausting vacuum equipment

1. 75 percent at 5 microns
2. 85 percent at 1 micron
3. 95 percent at 10 microns
4. 99.97 percent at 0.3 micron

Correct Answer: 4. 99.97 percent at 0.3 micron

Explanation:

NADCA specifies that vacuum collection equipment exhausting within the building envelope must use HEPA filtration with a collection efficiency of 99.97 percent at a particle size of 0.3 micron. This filtration requirement helps prevent fine particles removed from the HVAC system from being released back into occupied indoor areas. Vacuum collection equipment is an important part of source removal cleaning because it captures debris loosened through agitation. When exhaust remains indoors, high efficiency filtration provides an essential engineering control for protecting the indoor environment during cleaning.

Question 64. What must be verified during negative pressure cleaning

1. Outdoor temperature
2. Pressure differential
3. Building occupancy count
4. Refrigerant charge

Correct Answer: 2. Pressure differential

Explanation:

The pressure differential between the portion of the HVAC system being cleaned and surrounding indoor spaces must be verified during the cleaning project. Continuous negative pressure helps prevent loosened particulate matter from escaping from the duct or component into occupied areas. NADCA specifically requires verification at representative locations rather than assuming that connecting a vacuum automatically creates sufficient pressure everywhere. Proper verification confirms that the collection equipment and project setup are performing as intended throughout the cleaning process.

Question 65. How should contaminated material be handled before leaving the building

1. Properly contained
2. Spread out to dry
3. Returned to the duct
4. Mixed with clean equipment

Correct Answer: 1. Properly contained

Explanation:

Contaminated materials removed from HVAC components should be properly contained before they are transported out of the building. This requirement helps prevent cross contamination of occupied areas, hallways, elevators, and other spaces between the work location and the disposal point. If material is considered hazardous, additional handling and disposal requirements may apply according to relevant regulations. Proper containment is therefore part of the complete source removal process. Removing debris from ductwork is not sufficient if that same material is then allowed to contaminate another part of the building.

Question 66. What minimum air cleaning rate is recommended for ambient HEPA air scrubbers

1. One air change per hour
2. Two air changes per hour
3. Four air changes per hour
4. Twelve air changes per hour

Correct Answer: 3. Four air changes per hour

Explanation:

NADCA recommends that ambient air cleaning with HEPA filtered air scrubbers provide a minimum of four air changes per hour when used as a supplemental engineering control. Ambient air cleaning can help reduce airborne particles generated during HVAC cleaning and restoration activities. It is considered supplemental because it does not replace source removal or negative pressure within the system. Contaminants still need to be physically removed from HVAC surfaces. Air scrubbers help manage particles that may become airborne within the work environment during and immediately after cleaning activities.

Question 67. What should be available if negative pressure equipment fails

1. Extra duct insulation
2. Redundant equipment
3. Additional refrigerant
4. Larger supply registers

Correct Answer: 2. Redundant equipment

Explanation:

NADCA recommends having redundant equipment available on site in case equipment maintaining negative pressure fails. Loss of negative pressure can allow loosened contamination to migrate from the HVAC system into surrounding indoor spaces. Backup equipment allows technicians to restore the required pressure control quickly and reduce the chance of cross contamination. This recommendation demonstrates why equipment planning is part of project safety and engineering controls. A technician should consider not only normal operation but also how the project will remain controlled if critical cleaning equipment unexpectedly stops working.

Question 68. What should protective coverings safeguard during cleaning

1. Refrigerant lines only
2. Outdoor landscaping
3. Roof drainage
4. Floors equipment and furniture

Correct Answer: 4. Floors equipment and furniture

Explanation:

Level 1 containment includes the use of clean protective coverings where needed to protect floors, equipment, furniture, and other surfaces around the work area. HVAC cleaning can disturb large quantities of particulate material, and tools or hoses can also affect nearby finishes and contents. Protective coverings should extend beyond the immediate work area when necessary. The purpose is to prevent the cleaning process from damaging or contaminating parts of the building that were not originally affected. Containment and housekeeping are therefore important components of professional HVAC cleaning practice.

Question 69. Where should service openings preferably be made when existing access is available

1. Through existing suitable openings
2. Through flexible duct walls
3. Through electrical panels
4. Through fire dampers

Correct Answer: 1. Through existing suitable openings

Explanation:

Where possible, technicians should use suitable existing openings such as supply diffusers, return grilles, duct end caps, and existing service openings to gain access for inspection and cleaning. Additional openings may be created when necessary to reach internal surfaces effectively. Using existing access can reduce unnecessary alteration of the HVAC system while still allowing proper cleaning. Any new access opening must be created and closed in a way that preserves structural, thermal, and functional integrity and does not adversely affect airflow.

Question 70. What is prohibited in flexible ductwork

1. Air movement
2. Visual inspection
3. Existing connections
4. Creating service openings

Correct Answer: 4. Creating service openings

Explanation:

NADCA states that service openings should not be made in flexible ductwork. Flexible ducts differ from rigid metal duct systems and can be damaged if technicians cut access holes into their walls. Cleaning methods therefore need to account for the construction and condition of the flexible duct. Technicians should use appropriate existing access points and methods that do not compromise the duct material. If flexible duct is damaged or cannot be restored effectively, replacement may be more appropriate than creating unauthorized access that weakens the system.

Question 71. What must be avoided when creating access in fibrous glass duct systems

1. Metal fasteners
2. Exposed fibrous glass edges in the airstream
3. Existing inspection points
4. External identification labels

Correct Answer: 2. Exposed fibrous glass edges in the airstream

Explanation:

Service openings in fibrous glass systems must be created and closed so that fibrous glass edges are not left exposed to the internal airstream. Any insulation removed during access creation should also be repaired or replaced with material of the same thickness so thermal and vapor barrier characteristics are maintained. Poor access construction can degrade insulation performance and expose damaged material to moving air. NADCA therefore requires technicians to consider both access needs and the long term condition of the fibrous glass system when performing cleaning work.

Question 72. What rating standard should materials closing a drilled service opening satisfy

1. UL 181 requirements
2. Plumbing code only
3. Roofing standards
4. Electrical motor standards

Correct Answer: 1. UL 181 requirements

Explanation:

NADCA requirements state that materials used to close drilled one inch service openings should meet UL 181 requirements related to flame spread and smoke generation. These openings may be created for inspection or certain cleaning procedures, but they must be closed with materials suitable for HVAC duct applications. Using inappropriate plugs or materials can create durability, leakage, or fire performance concerns. Proper closure is part of restoring the HVAC system after access has been created and helps ensure that cleaning does not leave the duct system in a degraded condition.

Question 73. What should never result from wet cleaning

1. Cleaner surfaces
2. Debris removal
3. Damage to HVAC components
4. Wastewater collection

Correct Answer: 3. Damage to HVAC components

Explanation:

Wet cleaning, power washing, steam cleaning, and other wet processes must not damage HVAC system components or cause later damage. Water can affect electrical devices, insulation, porous materials, finishes, and other sensitive parts of an HVAC system if used incorrectly. Technicians should determine whether a component is suitable for wet cleaning before applying water or cleaning solutions. Appropriate collection and drying methods are also important. The cleaning method should improve the condition of the component without creating corrosion, moisture problems, electrical hazards, or structural deterioration.

Question 74. Where should water or cleaning agents generally not be applied

1. Smooth metal drain pans
2. Electrical or porous components
3. Suitable washable coils
4. Approved nonporous surfaces

Correct Answer: 2. Electrical or porous components

Explanation:

NADCA commercial cleaning guidance states that cleaning agents or water should not be applied to electrical, fibrous glass, or other porous HVAC system components. These materials can be damaged by moisture or can retain cleaning solutions in ways that create additional problems. Wet methods are better suited to compatible nonporous components when proper containment and extraction are available. Before selecting any cleaning process, the technician should identify the component material, contamination type, manufacturer requirements, and potential for damage. The safest effective method should be selected for each surface.

Question 75. What must vacuum collection equipment have enough capacity to maintain

1. Negative pressure in the cleaning area
2. Higher refrigerant pressure
3. Increased indoor humidity
4. Maximum supply temperature

Correct Answer: 1. Negative pressure in the cleaning area

Explanation:

Vacuum collection equipment should have sufficient capacity to maintain the portion of the HVAC system being cleaned under negative pressure. This pressure relationship helps contain loosened debris and prevents contaminants from migrating into adjacent occupied areas. Equipment capacity must therefore match the system section, duct size, leakage, access setup, and cleaning method. Simply connecting a vacuum does not guarantee that adequate negative pressure exists. The pressure differential should be verified during the project so technicians know that contaminant control remains effective while agitation and source removal are taking place.

Question 76. What is the purpose of visual inspection equipment during cleaning

1. Increase blower speed
2. Measure refrigerant level
3. Add antimicrobial products
4. Monitor contamination and cleaning progress

Correct Answer: 4. Monitor contamination and cleaning progress

Explanation:

Visual inspection equipment allows technicians to examine areas inside HVAC systems that may be difficult to see directly. These devices can be used before cleaning to evaluate contamination, during cleaning to monitor progress, and afterward to help evaluate the result. Examples can include cameras and other optical inspection tools. Inspection equipment supports more informed cleaning decisions because technicians can identify where contamination remains instead of relying only on assumptions. NADCA identifies inspection tools as an important category of equipment used during HVAC inspection, maintenance, and restoration projects.

Question 77. What is the main purpose of access tools

1. Measure humidity
2. Create entry points for inspection and cleaning
3. Test refrigerant pressure
4. Measure electrical current

Correct Answer: 2. Create entry points for inspection and cleaning

Explanation:

Access tools are used to create entry points into HVAC system components so technicians can inspect and clean internal surfaces. Access can range from small openings used for optical inspection to larger service panels that allow cleaning tools or personnel to reach internal areas. NADCA identifies access tools as an important category of HVAC cleaning equipment. Any opening created must be appropriate for the system material and must later be closed correctly so structural integrity, thermal performance, airflow, and safety are preserved.

Question 78. What should be considered before choosing a cleaning tool

1. Building paint color
2. Customer furniture style
3. Component material and condition
4. Outdoor landscaping

Correct Answer: 3. Component material and condition

Explanation:

Cleaning tools should be selected according to the HVAC component material, construction, condition, contamination, and accessibility. A method that works effectively on sheet metal could damage flexible duct, insulation, coatings, or delicate components. NADCA requires cleaning procedures to avoid damaging system components or negatively altering system integrity. Proper tool selection therefore requires understanding both the contamination and the surface being cleaned. The objective is to remove contaminants effectively while preserving the component so it remains suitable for continued HVAC operation after the work is complete.

Question 79. What is NADCA promoting when it identifies source removal as the acceptable cleaning approach

1. Physical removal of contamination
2. Covering contamination with paint
3. Increasing duct pressure
4. Leaving settled debris in place

Correct Answer: 1. Physical removal of contamination

Explanation:

NADCA states that its mission includes promoting source removal as the acceptable method of HVAC system cleaning. Source removal physically loosens and captures contaminants rather than simply covering them or moving them to another location. Mechanical agitation and vacuum collection are commonly combined so debris is separated from surfaces and removed from the system. This approach also requires proper pressure control and containment to prevent contaminants from escaping into occupied areas. The end goal is a system that achieves the specified cleanliness level after the contamination has actually been removed.

Question 80. What is the primary purpose of the current ACR Standard

1. Establish practices for HVAC assessment cleaning and restoration
2. Set refrigerant prices
3. Design building foundations
4. Regulate electrical utilities

Correct Answer: 1. Establish practices for HVAC assessment cleaning and restoration

Explanation:

ACR, The NADCA Standard, provides a recognized procedural framework for assessing, cleaning, and restoring HVAC systems. The current 2025 edition includes guidance on engineering controls, containment, component inspections, scope development, equipment use, negative air pressure, cleaning methods, and cleanliness verification. It is intended for contractors, facility managers, specifiers, and others responsible for HVAC system hygiene. The Standard establishes consistent expectations so cleaning and restoration work can be planned and evaluated according to recognized industry practices rather than relying entirely on individual contractor preferences.