NAFA CAFS TEST CERTIFICATION
EVALUATION EXAMS SET SOLVED
QUESTIONS AND VERIFIED DETAILED
ANSWERS
⩥ A micron is approximately ___________ of an inch..
Answer: 1/25,400".
NAFA Guide to Air Filtration, 5th ed. 2014, page 1.2
⩥ Particle counters used to use tungsten light, and were limited to
measuring particle sizes down to 0.3 microns. Newer units, using
___________ as a source of light, have the capability of counting
particles smaller than 0.1 micron..
Answer: Lasers.
NAFA Guide to Air Filtration, 5th ed. 2014, page 1.5
⩥ If you have a 20x24x12 filter, with 48sq. ft. of media, placed in an
airstream of 2000cfm, what would your velocity(fpm) be?.
Answer: 41.66fpm.
,V(fpm)=Q(cfm)/A(Sq. ft. of media)
NAFA Guide to Air Filtration, 5th ed. 2014, page 2.1
⩥ Electronic Air Cleaners are externally powered devices. True or
false?.
Answer: True.
NAFA Guide to Air Filtration, 5th ed. 2014, page 2.3
⩥ The thicker the filter media and the closer the orientation of fibers, the
________ the possibility of collision by a fiber..
Answer: Greater.
NAFA Guide to Air Filtration, 5th ed. 2014, page 2.4
⩥ Impingement filters are frequently treated with adhesives that coat the
fibers and create a bond between the particle and the fiber. True or
false?.
Answer: True.
NAFA Guide to Air Filtration, 5th ed. 2014, page 2.5
, ⩥ A dipole moment is when there is a ________ _____________ of
electrons at ____ _______ of a molecule than there is at ____________..
Answer: Greater concentration.
One end.
Another.
NAFA Guide to Air Filtration, 5th ed. 2014, page 2.6
⩥ The strongest force occurs between particles and fibers that are
___________ ____ _____ ________..
Answer: Approximately the same diameter.
NAFA Guide to Air Filtration, 5th ed. 2014, page 2.6
⩥ What is capacity?.
Answer: The amount of air that a filter can handle. (cfm)
NAFA Guide to Air Filtration, 5th ed. 2014, page 2.7
⩥ What is dust holding capacity?.
Answer: The amount of dust retained by a filter to its final
recommended pressure drop.
EVALUATION EXAMS SET SOLVED
QUESTIONS AND VERIFIED DETAILED
ANSWERS
⩥ A micron is approximately ___________ of an inch..
Answer: 1/25,400".
NAFA Guide to Air Filtration, 5th ed. 2014, page 1.2
⩥ Particle counters used to use tungsten light, and were limited to
measuring particle sizes down to 0.3 microns. Newer units, using
___________ as a source of light, have the capability of counting
particles smaller than 0.1 micron..
Answer: Lasers.
NAFA Guide to Air Filtration, 5th ed. 2014, page 1.5
⩥ If you have a 20x24x12 filter, with 48sq. ft. of media, placed in an
airstream of 2000cfm, what would your velocity(fpm) be?.
Answer: 41.66fpm.
,V(fpm)=Q(cfm)/A(Sq. ft. of media)
NAFA Guide to Air Filtration, 5th ed. 2014, page 2.1
⩥ Electronic Air Cleaners are externally powered devices. True or
false?.
Answer: True.
NAFA Guide to Air Filtration, 5th ed. 2014, page 2.3
⩥ The thicker the filter media and the closer the orientation of fibers, the
________ the possibility of collision by a fiber..
Answer: Greater.
NAFA Guide to Air Filtration, 5th ed. 2014, page 2.4
⩥ Impingement filters are frequently treated with adhesives that coat the
fibers and create a bond between the particle and the fiber. True or
false?.
Answer: True.
NAFA Guide to Air Filtration, 5th ed. 2014, page 2.5
, ⩥ A dipole moment is when there is a ________ _____________ of
electrons at ____ _______ of a molecule than there is at ____________..
Answer: Greater concentration.
One end.
Another.
NAFA Guide to Air Filtration, 5th ed. 2014, page 2.6
⩥ The strongest force occurs between particles and fibers that are
___________ ____ _____ ________..
Answer: Approximately the same diameter.
NAFA Guide to Air Filtration, 5th ed. 2014, page 2.6
⩥ What is capacity?.
Answer: The amount of air that a filter can handle. (cfm)
NAFA Guide to Air Filtration, 5th ed. 2014, page 2.7
⩥ What is dust holding capacity?.
Answer: The amount of dust retained by a filter to its final
recommended pressure drop.
