Browse all practice questions for the NAFA Certified Air Filter Specialist (CAFS) Practice Exam. Search by topic, open any question and review its full explanation, then test yourself in the practice quiz.

CAFS Certification Practice Exam 2026 – Complete Study Resource course image
All questions

These questions are part of the practice quiz. Start practicing

  • What are the main components of a HEPA filter?
  • What role do filtration systems play in indoor air quality control?
  • What is the primary purpose of a plenum in a baghouse system?
  • What is the primary function of ceiling diffusion media?
  • Which of the following can hinder the process of adsorption?
  • What are the two types of cleanroom filters?
  • What is an important consideration in the design of finishing booths?
  • A baghouse is typically composed of which components?
  • Which of the following is NOT a characteristic of impingement filters?
  • Why is industrial finishing employed in manufacturing processes?
  • Which of the following are types of PCO reactors?
  • How can absorption be defined in the context of air filtration?
  • What is the primary purpose of a filter's frame?
  • How is welding smoke typically removed in industrial settings?
  • Which rating is used to quantify the efficiency of an air filter in removing aerosols?
  • Which standard defines the testing method for air filter efficiency?
  • What organization is referred to by the acronym ASHRAE?
  • What is the recommended level of airflow in a cleanroom environment?
  • In terms of filtration media, what does "depth loading" refer to?
  • How is "capacity" defined in the context of air filter media?
  • What kind of particles are HEPA filters specifically designed to capture?
  • How does Ultraviolet Germicidal Irradiation (UVGI) function?
  • Even though smaller than 0.3 microns, HEPA filters can remove?
  • What certification can air filters earn to signify their performance?
  • Which of the following is typically NOT a method of collecting particles in air filtration?
  • How many broad composite categories does ANSI/ASHRAE 52.2 average particles in?
  • How do temperature changes affect air filter performance?
  • For what purpose are high MERV rating filters typically used?
  • What are the two main objectives of dust separation?
  • What is meant by "graduating density" in filter design?
  • How many classifications of air contaminants are recognized?
  • What are the different types of air cleaners?
  • What is one advantage of using electrostatic filters?
  • What can result from running filters to their maximum pressure drop?
  • What generally determines the efficiency of a filter?
  • Which process is defined as the collection of gas molecules on solid surfaces?
  • What maintenance is typically required for electrostatic air filters?
  • What is a HEPA filter's efficiency at capturing 0.3 micron particles?
  • How is the total cost of filtration determined?
  • What does MERV stand for in the context of air filters?
  • What are the main sections of a typical oil mist electrostatic precipitator from inlet to outlet?
  • What happens to filtration efficiency as an air filter becomes clogged?
  • What is meant by a filter's "initial efficiency"?
  • If static pressure goes up, velocity pressure goes?
  • What is the primary focus of total retention filters?
  • What does ASHRAE standard 62.1/62.2 specify?
  • What allows for retrofit without large pressure increases in the system?
  • Which air filter type is typically made of electrostatically charged fibers?
  • What is the name for the issue when a person comes into a building and experiences flu-like symptoms?
  • Which of the following is NOT a method to control molecular contaminants?
  • What should be provided when exhaust air exceeds intake air?
  • What is an aerosol?
  • What is a potential drawback of PCO systems?
  • What are the two types of filter options mentioned?
  • What type of air filter is typically used in industrial settings for heavy-duty particles?
  • What is the minimum efficiency for a Super ULPA filter on MPPS?
  • Which size particles behave like a gas and are affected by Brownian Motion?
  • What unintended consequence can result from underrating a filter?
  • What is a common feature of disposable air filters?
  • What is 1 millionth of a meter commonly referred to as?
  • What is a characteristic of electronic air cleaners?
  • When is a dirty filter most likely to be problematic?
  • What is the main function of the natural ventilation procedure?
  • What type of environment benefits significantly from high-efficiency particulate filters (HEPA)?
  • In which situation is a pleated air filter preferred over a flat filter?
  • Which method is commonly used to measure air filter performance?
  • What is a primary function of an air filter?
  • What are the three procedures for engineers outlined in the ASHRAE standard 62.1?
  • Why is static pressure an important factor in air filtration?
  • What typically happens to filter efficiency as dirt accumulates?
  • What is the main purpose of measuring pressure drop across a filter?
  • In what context is Brownian motion relevant?
  • What is the relationship between airflow rate and filter efficiency?
  • What does MPPS stand for in terms of airborne particles?
  • What is the goal of dilution as a control strategy?
  • How many types of reactor configurations are there in Photocatalytic Oxidation (PCO)?
  • Bacteria reproduce by?
  • What is the minimum efficiency required for demonstrated overspray filter performance?
  • What are the primary principles of particulate air filtration?
  • What is the minimum efficiency required for ULPA filters?
  • How does particle size impact the choice of air filter?
  • A particle size of 1 micrometer is equivalent to how many microns?
  • What type of filters would be most suitable for capturing smoke and VOCs?
  • What is a primary role of an air filter technician?
  • What term describes the rated flow of air through a filter at a specified pressure drop?
  • Which characteristic defines impingement filters?
  • Tuberculosis patients must be kept in rooms that are?
  • What type of system uses UVGI lights effectively?
  • What characterizes a pocket filter?
  • UVGI is most effective on microorganisms within which range of the light spectrum?
  • What common signs suggest that an air filter may need replacing?
  • Which type of air filter is best for individuals suffering from allergies?
  • What role does an air filter play in terms of energy efficiency?
  • What is the primary goal of using MERV ratings?
  • What is a key reason for capturing aerosolized metal working fluids?
  • What is chemisorption?
  • Which type of filter is known for its ability to capture odors and gaseous pollutants?
  • What is measured by a manometer in the filter industry?
  • What are the four principles of air filtration?
  • What is the typical efficiency rating for a MERV 8 filter?
  • What is a key benefit of using an air filter with an antimicrobial coating?
  • What distinguishes hot DOP from cold DOP testing?
  • What are the key principles of airflow in HVAC systems?
  • What does MERV stand for in air filtration?
  • What is the MERV rating of lofted microglass media that is color-coded yellow?
  • How often should disposable air filters generally be replaced?
  • What is the role of pre-filters in an air filtration system?
  • How does surface area impact air filter efficiency?
  • What does ULPA stand for in air filtration?
  • Why must gas turbine supply air be free of 5 micrometer particles?
  • What is a common measurement unit used for assessing air particle sizes?
  • What role do HEPA filters primarily serve in air purification?
  • To be classified as a HEPA filter, what minimum efficiency must it achieve?
  • What is the significance of 'pressure drop' in relation to air filters?
  • A major source of pollution in a building is?
  • How does high initial equipment cost affect the adoption of PCO technology?
  • What percentage of the total cost of a filter is attributed to energy costs?
  • What are the two advantages of Minipleat filters?
  • Which feature of HEPA filters makes them highly effective?
  • Which factor does NOT determine the life of an air filter?
  • Metal working fluids are used to?
  • What is the primary benefit of using high-efficiency filters in residential systems?
  • What does the term "straining" refer to in HVAC systems?
  • What does the term 'final resistance' refer to in filter technology?
  • How does high relative humidity impact the performance of certain air filters?
  • How does the frequency of filter replacement influence air quality?
  • Which of the following factors does NOT affect mechanical filter selection?
  • Testing HEPA filters after installation is called?
  • What is the purpose of a pre-filter in an HVAC system?
  • Which factor contributes to the efficiency of a mechanical filter?
  • What precaution should technicians take before servicing units with installed UV lights?
  • A two-stage air cleaner utilizes which two components?
  • What types of filters are used for mist and smoke removal?
  • When does interception occur in air filtration?
  • Which styles are utilized in dust separation equipment?
  • What are the categories of impingement filters?
  • How does air filter media affect its filtration efficiency?
  • What is referred to as media velocity in air filtration systems?
  • What is a common consequence of inadequate ventilation in offices?
  • Which type of air filter is known for the best efficiency in reducing allergens?
  • What type of particles are most effectively removed by HEPA filters?
  • What testing method is used to best determine filter efficiency?
  • Healthcare facilities follow filter guidelines of?
  • What is the primary function of make up air in an HVAC system?
  • What is the primary purpose of HVAC testing?
  • How do impingement filters function?
  • What aspect does the ANSI/ASHRAE 52.2 test specifically measure in filters?
  • Which of the following best describes chemically treated carbon media?
  • Which characteristic is NOT used to classify microorganisms in air filtration?
  • Which characteristic is NOT associated with HEPA filters?
  • What is the typical size of particles found in outdoor air?
  • What does VOC stand for in air quality terms?
  • Which materials are commonly used for HEPA frames?
  • What is meant by "removal efficiency"?
  • Which of the following describes a variation of the contamination control principle?
  • What does the term "Pressure Drop" refer to in air filter performance?
  • What does pressure drop indicate in a filtration system?
  • What characterizes particulate contamination?
  • What are common applications for Indoor Air Quality (IAQ) testing?
  • What are the two general categories of Enclosed Finish Booths?
  • What factors influence the effectiveness of impingement filters?
  • What does the acronym PCO stand for in air filtration?
  • Which type of filter operates with low pressure drop and high airflow?
  • In terms of air filtration, what does a higher face velocity typically indicate?
  • What type of air filter should be used in a clean room environment?
  • Which two types of gasketing are used for HEPA filters?
  • Which of the following best defines gas?
  • How do mechanical filters effectively remove dust?
  • Which factors affect the design and efficiency of an Electrostatic Precipitator (ESP)?
  • What is the name of the current European Air Filter Standard?
  • What is the main drawback of using fiberglass filters?
  • A breather filter is used to protect the contents of:
  • What is one advantage of PCO technology in air purification?
  • How does the design of extended surface filters impact their performance?
  • Which gas is often considered a trace component in the atmosphere, making up only about 0.04%?
  • What type of air filter is most commonly found in residential HVAC systems?
  • Which condition must be met regarding electrostatic precipitator design?
  • What is defined as the speed of the air as it moves through the filter media?
  • What does the process of dust recovery aim to achieve?
  • What is the process of gas adhering to surfaces known as?
  • What advantage does synthetic air filter media have over fiberglass media?
  • What does the term 'air changes per hour' refer to in filtration?
  • Why is it important to monitor static pressure in an HVAC system?
  • How does filter location impact filter function in HVAC systems?
  • What is a common filter media used in HEPA filters?
  • What environmental factors can affect an air filter's lifespan?
  • What factors should be considered when selecting air filters for a hospital?
  • What is a common challenge when using high-MERV filters in residential HVAC systems?
  • What does the term "residence time" refer to?
  • What standard must baffle grease filters meet?
  • What types of sealants are used in HEPA filters?
  • Why are some air filters labeled as "washable"?
  • Lofted glass media is most commonly found in which style of filter?
  • What are the three types of media commonly used in contaminant control?
  • What is the primary component of the air we breathe?
  • What are the main types of microorganisms relevant in air filtration?
  • What is the primary function of air filters in a HVAC system?
  • What is a key component of a baghouse system?
  • What must airflow through a booth achieve to control VOC vapor concentration?
  • Which of the following describes the types of cleanrooms?
  • What does MERV stand for?
  • Why is it recommended to install UVGI lights downstream of filters?
  • What is the function of the initial resistance in air filters?
  • What is a crucial aspect of adherence in adsorption?
  • The air composition that makes up about 78% of the atmosphere is primarily?
  • What are the size ranges for the E1, E2, and E3 categories in ANSI/ASHRAE 52.2?
  • Which factors significantly affect filter life?
  • What is defined as the pressure required to move air through a filter at a certain airflow?
  • How can humidity levels influence air filter performance?
  • What characterizes the optimum final pressure drop in filtration systems?
  • What does HEPA filter testing measure?
  • What advantage do electrostatic filters have compared to traditional filters?
  • How does an electronic air cleaner collect particles?
  • Which type of air filter is typically used in hospital environments?
  • What is the importance of filter size in HVAC systems?
  • What are the two main methods for molecular contaminant removal?
  • What is one method used to maintain the efficiency of air filters?
  • Why is it important to evaluate filter efficiency at different airflow rates?
  • What are the types of HEPA separator styles?
  • What does a higher MERV rating indicate about an air filter?
  • Which characteristics can make an overspray filter hazardous?
  • Who would primarily benefit from the knowledge of overspray filter characteristics?
  • Impingement filters primarily capture particles based on their:
  • What is a consequence of not changing air filters regularly?
  • What happens to contaminant particles during the straining process?
  • Which type of charging method is NOT considered an active charged media type?
  • What is the main function of an air filtration system?
  • Which factor is essential for the effectiveness of HEPA filters?
  • What does ANSI/ASHRAE 52.2 - 2012 primarily measure?
  • What does UVGI stand for?
  • What does the term "face velocity" refer to?
  • What function does the collecting section of an electrostatic precipitator serve?
  • What are the two main categories of enclosed finishing booths?
  • What are vapors in the context of air quality?
  • What role does airflow play in filter selection?
  • Which phenomenon explains the capture of very small particles through erratic motion?
  • Why is it not possible to test electronic air cleaners for loading using the ASHRAE 52.2 test?
  • What are the strategies employed for controlling air contamination?
  • What types of efficiencies contribute to energy costs in air systems?
  • What is the common dimension for HVAC air filter sizes?
  • Which of the following is a common use for activated carbon filters?
  • Which of the following describes types of metal working fluids?
  • How is the removal of dust performed on an electronic air cleaner?
  • Which type of aerosol is used in the ASHRAE standard dust test?
  • What does "dust holding capacity" indicate?
Subscribe

Get the latest from Examzify

You can unsubscribe at any time. Read our privacy policy