NAFA CAFS TEST EXAM FULLY SOLVED & UPDATED 2026(LATEST VERSION VERIFIED FOR
ACCURACY)/NEWEST UPDATE!!!
Question 1
Which of the following are the three primary types of media used specifically for gas-phase or
molecular contaminant control?
A) Activated carbon, fiberglass, and polyester
B) Active carbon, chemically treated carbon, and potassium permanganate
C) HEPA media, ULPA media, and Super ULPA media
D) Synthetic fibers, metal mesh, and foam
E) Cotton-polyester blends, pleated paper, and active carbon
Correct Answer: B) Active carbon, chemically treated carbon, and potassium permanganate
Rationale: Contaminate control for gases requires molecular filtration. Active carbon
(adsorption), chemically treated carbon (chemisorption), and potassium permanganate
(oxidation) are the standard media types used to remove odors and gaseous pollutants.
Question 2
How is "residence time" defined in the context of molecular filtration?
A) The time a technician spends replacing a filter pack
B) The total lifespan of a filter before it reaches final resistance
C) The time it takes air to cross a distance equal to the media thickness without accounting for
resistance
D) The time it takes for a manometer to reach zero after a system shutdown
E) The interval between the initial and final pressure drop readings
Correct Answer: C) the time it takes air to cross a distance equal to the thickness of the filter
without accounting for the resistance of the media through which it travels
Rationale: Residence time is a critical calculation in gas-phase filtration because it
determines how long the gaseous contaminants are in contact with the media to allow for
physical or chemical removal.
Question 3
Which of the following is NOT one of the variations of the contamination control principle?
A) Cleaning the air required by the specific process
B) Blanketing the product with cleaned air
C) Offering enough air flow to move contaminated air away from the product
D) Recirculating contaminated air to increase media temperature
E) Controlling the source of the contaminant through filtration
Correct Answer: D) Recirculating contaminated air to increase media temperature
Rationale: The three pillars of contamination control are cleaning the air for the process,
protecting the product with a "blanket" of clean air, and using dilution or exhaust to pull
contaminants away. Recirculating contaminated air for temperature purposes is not a
control principle.
, 2
Question 4
In air filtration, "removal efficiency" is best described as:
A) The total weight of dust captured by the filter
B) The fraction of the contaminant removed once it makes contact with the media
C) The speed of the air moving through the filter face
D) The percentage of the budget allocated to energy costs
E) The physical thickness of the media fibers
Correct Answer: B) The fraction of the contaminate that once in contact with the media is
removed by either physical or chemical means
Rationale: Efficiency measures the effectiveness of the media in stopping particles or gases
from passing through. It is typically expressed as a percentage of the total challenge
presented to the filter.
Question 5
What determines the "Capacity" of a filter media?
A) The size of the room the filter is cleaning
B) The amount of contaminant the media is capable of removing before needing replacement
C) The maximum velocity the motor can produce
D) The distance between the ionizer and the collector plates
E) The number of pleats per linear foot
Correct Answer: B) The amount the media is capable of removing - this determines the life
of the filter
Rationale: Capacity refers to the "holding power" of the filter. Once a filter reaches its
capacity, the pressure drop usually becomes too high, signaling the end of the filter's service
life.
Question 6
What are the two primary filter configuration options regarding the air stream?
A) Manual and Automatic
B) Horizontal and Vertical
C) Partial bypass and total retention
D) Single-stage and Triple-stage
E) Electrostatic and Mechanical
Correct Answer: C) partial bypass, total retention
Rationale: Total retention filters process 100% of the air stream, whereas partial bypass
filters allow some air to circumvent the media, often used in specific industrial or
residential retrofits.
Question 7
What is the primary focus of ASHRAE Standard 62.1 and 62.2?
A) Testing the MERV rating of residential filters
, 3
B) Defining ventilation for acceptable indoor air quality (IAQ)
C) Standardizing the size of filter frames
D) Regulating the disposal of hazardous metal working fluids
E) Setting the noise levels for HVAC fans
Correct Answer: B) Ventilation for acceptable indoor air quality to specific minimum
ventilation rates IAQ which will be acceptable to humans and are intended to avoid
adverse health effects
Rationale: Standard 62.1 (commercial) and 62.2 (residential) specify minimum ventilation
rates and other measures intended to provide IAQ that is acceptable to human occupants.
Question 8
In the classification of air for ventilation purposes, how many distinct classifications are there?
A) 2
B) 3
C) 4
D) 5
E) 10
Correct Answer: C) 4
Rationale: ASHRAE 62.1 classifies air into four categories based on the level of
contaminants, with Class 1 being the cleanest (re-circulatable) and Class 4 being highly
contaminated (must be exhausted).
Question 9
Which of the following is an application of IAQ testing?
A) Particulate contaminants
B) Gas phase contaminants
C) Systems integrity and comfort parameters
D) All of the above
E) Only A and B
Correct Answer: D) All of the above
Rationale: Comprehensive IAQ testing involves looking at physical particles, chemical
gases, the physical structure of the HVAC system, and human comfort factors like
temperature and humidity.
Question 10
What are the three primary control strategies for managing indoor air quality?
A) Heating, Cooling, and Humidification
B) Filtration, Source Removal, and Dilution
C) Masking, Venting, and Pressurizing
D) Absorption, Adsorption, and Chemisorption
E) Monitoring, Reporting, and Cleaning
ACCURACY)/NEWEST UPDATE!!!
Question 1
Which of the following are the three primary types of media used specifically for gas-phase or
molecular contaminant control?
A) Activated carbon, fiberglass, and polyester
B) Active carbon, chemically treated carbon, and potassium permanganate
C) HEPA media, ULPA media, and Super ULPA media
D) Synthetic fibers, metal mesh, and foam
E) Cotton-polyester blends, pleated paper, and active carbon
Correct Answer: B) Active carbon, chemically treated carbon, and potassium permanganate
Rationale: Contaminate control for gases requires molecular filtration. Active carbon
(adsorption), chemically treated carbon (chemisorption), and potassium permanganate
(oxidation) are the standard media types used to remove odors and gaseous pollutants.
Question 2
How is "residence time" defined in the context of molecular filtration?
A) The time a technician spends replacing a filter pack
B) The total lifespan of a filter before it reaches final resistance
C) The time it takes air to cross a distance equal to the media thickness without accounting for
resistance
D) The time it takes for a manometer to reach zero after a system shutdown
E) The interval between the initial and final pressure drop readings
Correct Answer: C) the time it takes air to cross a distance equal to the thickness of the filter
without accounting for the resistance of the media through which it travels
Rationale: Residence time is a critical calculation in gas-phase filtration because it
determines how long the gaseous contaminants are in contact with the media to allow for
physical or chemical removal.
Question 3
Which of the following is NOT one of the variations of the contamination control principle?
A) Cleaning the air required by the specific process
B) Blanketing the product with cleaned air
C) Offering enough air flow to move contaminated air away from the product
D) Recirculating contaminated air to increase media temperature
E) Controlling the source of the contaminant through filtration
Correct Answer: D) Recirculating contaminated air to increase media temperature
Rationale: The three pillars of contamination control are cleaning the air for the process,
protecting the product with a "blanket" of clean air, and using dilution or exhaust to pull
contaminants away. Recirculating contaminated air for temperature purposes is not a
control principle.
, 2
Question 4
In air filtration, "removal efficiency" is best described as:
A) The total weight of dust captured by the filter
B) The fraction of the contaminant removed once it makes contact with the media
C) The speed of the air moving through the filter face
D) The percentage of the budget allocated to energy costs
E) The physical thickness of the media fibers
Correct Answer: B) The fraction of the contaminate that once in contact with the media is
removed by either physical or chemical means
Rationale: Efficiency measures the effectiveness of the media in stopping particles or gases
from passing through. It is typically expressed as a percentage of the total challenge
presented to the filter.
Question 5
What determines the "Capacity" of a filter media?
A) The size of the room the filter is cleaning
B) The amount of contaminant the media is capable of removing before needing replacement
C) The maximum velocity the motor can produce
D) The distance between the ionizer and the collector plates
E) The number of pleats per linear foot
Correct Answer: B) The amount the media is capable of removing - this determines the life
of the filter
Rationale: Capacity refers to the "holding power" of the filter. Once a filter reaches its
capacity, the pressure drop usually becomes too high, signaling the end of the filter's service
life.
Question 6
What are the two primary filter configuration options regarding the air stream?
A) Manual and Automatic
B) Horizontal and Vertical
C) Partial bypass and total retention
D) Single-stage and Triple-stage
E) Electrostatic and Mechanical
Correct Answer: C) partial bypass, total retention
Rationale: Total retention filters process 100% of the air stream, whereas partial bypass
filters allow some air to circumvent the media, often used in specific industrial or
residential retrofits.
Question 7
What is the primary focus of ASHRAE Standard 62.1 and 62.2?
A) Testing the MERV rating of residential filters
, 3
B) Defining ventilation for acceptable indoor air quality (IAQ)
C) Standardizing the size of filter frames
D) Regulating the disposal of hazardous metal working fluids
E) Setting the noise levels for HVAC fans
Correct Answer: B) Ventilation for acceptable indoor air quality to specific minimum
ventilation rates IAQ which will be acceptable to humans and are intended to avoid
adverse health effects
Rationale: Standard 62.1 (commercial) and 62.2 (residential) specify minimum ventilation
rates and other measures intended to provide IAQ that is acceptable to human occupants.
Question 8
In the classification of air for ventilation purposes, how many distinct classifications are there?
A) 2
B) 3
C) 4
D) 5
E) 10
Correct Answer: C) 4
Rationale: ASHRAE 62.1 classifies air into four categories based on the level of
contaminants, with Class 1 being the cleanest (re-circulatable) and Class 4 being highly
contaminated (must be exhausted).
Question 9
Which of the following is an application of IAQ testing?
A) Particulate contaminants
B) Gas phase contaminants
C) Systems integrity and comfort parameters
D) All of the above
E) Only A and B
Correct Answer: D) All of the above
Rationale: Comprehensive IAQ testing involves looking at physical particles, chemical
gases, the physical structure of the HVAC system, and human comfort factors like
temperature and humidity.
Question 10
What are the three primary control strategies for managing indoor air quality?
A) Heating, Cooling, and Humidification
B) Filtration, Source Removal, and Dilution
C) Masking, Venting, and Pressurizing
D) Absorption, Adsorption, and Chemisorption
E) Monitoring, Reporting, and Cleaning
