NAFA Certified Air Filter Specialist (CAFS)
Exam 2026 – 250 Actual Questions & Detailed
Solutions | Latest Updated Test Bank + Pass
Guarantee Guide
NAFA CERTIFIED AIR FILTER SPECIALIST (CAFS) EXAM 2026
Questions | Detailed Solutions | Latest Updated Test Bank
QUESTION 1
What does NAFA stand for in the context of air filtration?
A. National Air Flow Association
B. North American Filter Administrators
C. C. National Air Filtration Association
D. National Association of Filter Applicators
E. North American Filtration Authority
CORRECT ANSWER: C. National Air Filtration Association
RATIONALE: NAFA stands for the National Air Filtration Association. It is the primary
professional organization in North America dedicated to the air filtration industry. NAFA
provides education, certification programs (including the CAFS designation), and sets
industry standards for air filter professionals. It was founded to promote best practices in
the design, application, and maintenance of air filtration systems.
QUESTION 2
Which of the following best defines "air filtration"?
A. The process of cooling air to remove moisture
B. The mechanical compression of air to remove gases
C. The addition of chemicals to neutralize airborne pathogens
D. D. The removal of particulate matter and contaminants from an
airstream
E. The redistribution of air pressure in HVAC systems
,CORRECT ANSWER: D. The removal of particulate matter and contaminants from
an airstream
RATIONALE: Air filtration is fundamentally defined as the process of removing
particulate matter, contaminants, aerosols, and other undesirable substances from an
airstream. This is achieved through various mechanical, electrostatic, and chemical
means. The primary goal is to improve air quality for occupant health, protect
equipment, and maintain process integrity in industrial or commercial applications.
QUESTION 3
What is the primary purpose of an air filter in an HVAC system?
A. To regulate the temperature of supply air
B. To increase the velocity of airflow through ducts
C. C. To protect equipment and improve indoor air quality by removing
particles
D. To reduce the humidity levels in conditioned spaces
E. To balance static pressure between supply and return ducts
CORRECT ANSWER: C. To protect equipment and improve indoor air quality by
removing particles
RATIONALE: Air filters in HVAC systems serve two key purposes: first, to protect
mechanical components (coils, fans, heat exchangers) from dust buildup that can
reduce efficiency and cause premature failure; and second, to improve indoor air quality
by capturing particulate contaminants such as dust, pollen, mold spores, and other
allergens before they circulate through the occupied space.
QUESTION 4
Which of the following organizations publishes the MERV rating standard for air filters?
A. EPA (Environmental Protection Agency)
B. ISO (International Organization for Standardization)
C. NAFA (National Air Filtration Association)
D. NIOSH (National Institute for Occupational Safety and Health)
, E. E. ASHRAE (American Society of Heating, Refrigerating and Air-
Conditioning Engineers)
CORRECT ANSWER: E. ASHRAE (American Society of Heating, Refrigerating and
Air-Conditioning Engineers)
RATIONALE: The MERV (Minimum Efficiency Reporting Value) rating system was
developed and is published by ASHRAE under Standard 52.2. ASHRAE Standard 52.2
is titled "Method of Testing General Ventilation Air-Cleaning Devices for Removal
Efficiency by Particle Size." ASHRAE is the recognized authority for HVAC-related
standards in North America, and MERV is their standardized metric for comparing filter
efficiency across manufacturers.
QUESTION 5
What does MERV stand for?
A. Maximum Efficiency Rating Value
B. Minimum Efficiency Reporting Variable
C. C. Minimum Efficiency Reporting Value
D. Measured Efficiency Rating Value
E. Minimum Environmental Rating Verification
CORRECT ANSWER: C. Minimum Efficiency Reporting Value
RATIONALE: MERV stands for Minimum Efficiency Reporting Value. It is a
measurement scale developed by ASHRAE that rates the overall effectiveness of air
filters. The "minimum" in the name refers to the fact that the rating represents the worst-
case performance of the filter across the entire particle size range tested. MERV values
range from 1 (least efficient) to 20 (most efficient), helping consumers and engineers
select the appropriate filter for their application.
QUESTION 6
On the MERV scale, which range is most commonly used in residential HVAC systems?
A. MERV 1–4
B. B. MERV 5–13
C. MERV 14–16
, D. MERV 17–19
E. MERV 20
CORRECT ANSWER: B. MERV 5–13
RATIONALE: Residential HVAC systems typically use filters in the MERV 5–13 range.
MERV 5–8 filters capture larger particles like dust mites, mold spores, and pet dander.
MERV 9–12 filters offer improved efficiency, capturing finer dust and particles. MERV 13
is increasingly recommended for residential use due to its ability to capture fine particles
including some bacteria. Filters above MERV 13 create high pressure drops that most
residential systems cannot handle without modifications.
QUESTION 7
What is the particle size range (in microns) primarily targeted by MERV 8 filters?
A. 0.1–0.3 microns
B. 0.3–1.0 microns
C. C. 3.0–10.0 microns
D. 10.0–25.0 microns
E. 25.0–50.0 microns
CORRECT ANSWER: C. 3.0–10.0 microns
RATIONALE: MERV 8 filters are tested and rated for their ability to capture particles in
the 3.0–10.0 micron size range with a minimum efficiency of 70%. Common particles in
this size range include mold spores, dust mite debris, cement dust, and pet dander.
While MERV 8 filters also capture larger particles with higher efficiency, the MERV
rating itself is based on the particle size range where they perform at their rated
minimum.
QUESTION 8
Which filtration mechanism captures particles primarily through direct interception?
A. Electrostatic attraction
B. Diffusion
C. Gravitational settling
Exam 2026 – 250 Actual Questions & Detailed
Solutions | Latest Updated Test Bank + Pass
Guarantee Guide
NAFA CERTIFIED AIR FILTER SPECIALIST (CAFS) EXAM 2026
Questions | Detailed Solutions | Latest Updated Test Bank
QUESTION 1
What does NAFA stand for in the context of air filtration?
A. National Air Flow Association
B. North American Filter Administrators
C. C. National Air Filtration Association
D. National Association of Filter Applicators
E. North American Filtration Authority
CORRECT ANSWER: C. National Air Filtration Association
RATIONALE: NAFA stands for the National Air Filtration Association. It is the primary
professional organization in North America dedicated to the air filtration industry. NAFA
provides education, certification programs (including the CAFS designation), and sets
industry standards for air filter professionals. It was founded to promote best practices in
the design, application, and maintenance of air filtration systems.
QUESTION 2
Which of the following best defines "air filtration"?
A. The process of cooling air to remove moisture
B. The mechanical compression of air to remove gases
C. The addition of chemicals to neutralize airborne pathogens
D. D. The removal of particulate matter and contaminants from an
airstream
E. The redistribution of air pressure in HVAC systems
,CORRECT ANSWER: D. The removal of particulate matter and contaminants from
an airstream
RATIONALE: Air filtration is fundamentally defined as the process of removing
particulate matter, contaminants, aerosols, and other undesirable substances from an
airstream. This is achieved through various mechanical, electrostatic, and chemical
means. The primary goal is to improve air quality for occupant health, protect
equipment, and maintain process integrity in industrial or commercial applications.
QUESTION 3
What is the primary purpose of an air filter in an HVAC system?
A. To regulate the temperature of supply air
B. To increase the velocity of airflow through ducts
C. C. To protect equipment and improve indoor air quality by removing
particles
D. To reduce the humidity levels in conditioned spaces
E. To balance static pressure between supply and return ducts
CORRECT ANSWER: C. To protect equipment and improve indoor air quality by
removing particles
RATIONALE: Air filters in HVAC systems serve two key purposes: first, to protect
mechanical components (coils, fans, heat exchangers) from dust buildup that can
reduce efficiency and cause premature failure; and second, to improve indoor air quality
by capturing particulate contaminants such as dust, pollen, mold spores, and other
allergens before they circulate through the occupied space.
QUESTION 4
Which of the following organizations publishes the MERV rating standard for air filters?
A. EPA (Environmental Protection Agency)
B. ISO (International Organization for Standardization)
C. NAFA (National Air Filtration Association)
D. NIOSH (National Institute for Occupational Safety and Health)
, E. E. ASHRAE (American Society of Heating, Refrigerating and Air-
Conditioning Engineers)
CORRECT ANSWER: E. ASHRAE (American Society of Heating, Refrigerating and
Air-Conditioning Engineers)
RATIONALE: The MERV (Minimum Efficiency Reporting Value) rating system was
developed and is published by ASHRAE under Standard 52.2. ASHRAE Standard 52.2
is titled "Method of Testing General Ventilation Air-Cleaning Devices for Removal
Efficiency by Particle Size." ASHRAE is the recognized authority for HVAC-related
standards in North America, and MERV is their standardized metric for comparing filter
efficiency across manufacturers.
QUESTION 5
What does MERV stand for?
A. Maximum Efficiency Rating Value
B. Minimum Efficiency Reporting Variable
C. C. Minimum Efficiency Reporting Value
D. Measured Efficiency Rating Value
E. Minimum Environmental Rating Verification
CORRECT ANSWER: C. Minimum Efficiency Reporting Value
RATIONALE: MERV stands for Minimum Efficiency Reporting Value. It is a
measurement scale developed by ASHRAE that rates the overall effectiveness of air
filters. The "minimum" in the name refers to the fact that the rating represents the worst-
case performance of the filter across the entire particle size range tested. MERV values
range from 1 (least efficient) to 20 (most efficient), helping consumers and engineers
select the appropriate filter for their application.
QUESTION 6
On the MERV scale, which range is most commonly used in residential HVAC systems?
A. MERV 1–4
B. B. MERV 5–13
C. MERV 14–16
, D. MERV 17–19
E. MERV 20
CORRECT ANSWER: B. MERV 5–13
RATIONALE: Residential HVAC systems typically use filters in the MERV 5–13 range.
MERV 5–8 filters capture larger particles like dust mites, mold spores, and pet dander.
MERV 9–12 filters offer improved efficiency, capturing finer dust and particles. MERV 13
is increasingly recommended for residential use due to its ability to capture fine particles
including some bacteria. Filters above MERV 13 create high pressure drops that most
residential systems cannot handle without modifications.
QUESTION 7
What is the particle size range (in microns) primarily targeted by MERV 8 filters?
A. 0.1–0.3 microns
B. 0.3–1.0 microns
C. C. 3.0–10.0 microns
D. 10.0–25.0 microns
E. 25.0–50.0 microns
CORRECT ANSWER: C. 3.0–10.0 microns
RATIONALE: MERV 8 filters are tested and rated for their ability to capture particles in
the 3.0–10.0 micron size range with a minimum efficiency of 70%. Common particles in
this size range include mold spores, dust mite debris, cement dust, and pet dander.
While MERV 8 filters also capture larger particles with higher efficiency, the MERV
rating itself is based on the particle size range where they perform at their rated
minimum.
QUESTION 8
Which filtration mechanism captures particles primarily through direct interception?
A. Electrostatic attraction
B. Diffusion
C. Gravitational settling
