NATE EXAM CORE ESSENTIALS 121
COMPREHENSIVE STUDY GUIDE 2026 HVAC
AND REFRIGERATION SYSTEM PRINCIPLES
◉ d (all of the above: clear, complete, concise)
Answer: It is important to be ____ in filling out service orders so that
office staff, other technicians, and customers will know what work
you completed on the job.
a. clear
b. complete
c. concise
d. all of the above
◉ d (Refrigerant)
Answer: When explaining to a customer that you have adjusted the
system charge, which of the following terms is most appropriate?
a. Freon
b. Gas
c. Juice
d. Refrigerant
,◉ a (can help you diagnose the problem)
Answer: Listening carefully to what a customer is telling you ____.
a. can help you diagnose the problem
b. is a waste of time
c. is not necessary
d. often will only confuse you
◉ b (listen to the customer first, then ask questions)
Answer: When you arrive at a service call and meet the customer,
you should ____.
a. ask questions first, then listen to what the customer has to say
b. listen to the customer first, then ask questions
c. avoid discussion with the customer
d. remind the customer that you are the professional and get on with
your work
◉ b (1,600 ft3)
Answer: What is the volume of a room that measures 10 ft by 20 ft
with an 8-ft ceiling?
,a. 800 ft3
b. 1,600 ft3
c. 2,400 ft3
d. 3,200 ft3
◉ b (1,200 CFM)
Answer: What is the CFM requirements for an 1,800-ft2 house with
8-ft ceilings, if five air changes per hour are needed?
a. 400 CFM
b. 1,200 CFM
c. 1,600 CFM
d. 2,400 CFM
◉ c (1,600 CFM)
Answer: What is the CFM requirement for an 2,400-ft2 house with 8-
ft ceilings, if five air changes per hour are needed?
a. 400 CFM
b. 1,200 CFM
c. 1,600 CFM
, d. 2,400 CFM
◉ a (79 in2)
Answer: What is the cross-sectional area of a 10-in round metal
duct?
a. 79 in2
b. 200 in2
c. 314 in2
d. 418 in2
Note: Area of a circle = π x radius^2
◉ d (1,800 ft/min)
Answer: How fast does air with a velocity pressure of 0.20 in. w.g.
move through a round duct?
a. 400 ft/min
b. 1,200 ft/min
c. 1,600 ft/min
d. 1,800 ft/min
COMPREHENSIVE STUDY GUIDE 2026 HVAC
AND REFRIGERATION SYSTEM PRINCIPLES
◉ d (all of the above: clear, complete, concise)
Answer: It is important to be ____ in filling out service orders so that
office staff, other technicians, and customers will know what work
you completed on the job.
a. clear
b. complete
c. concise
d. all of the above
◉ d (Refrigerant)
Answer: When explaining to a customer that you have adjusted the
system charge, which of the following terms is most appropriate?
a. Freon
b. Gas
c. Juice
d. Refrigerant
,◉ a (can help you diagnose the problem)
Answer: Listening carefully to what a customer is telling you ____.
a. can help you diagnose the problem
b. is a waste of time
c. is not necessary
d. often will only confuse you
◉ b (listen to the customer first, then ask questions)
Answer: When you arrive at a service call and meet the customer,
you should ____.
a. ask questions first, then listen to what the customer has to say
b. listen to the customer first, then ask questions
c. avoid discussion with the customer
d. remind the customer that you are the professional and get on with
your work
◉ b (1,600 ft3)
Answer: What is the volume of a room that measures 10 ft by 20 ft
with an 8-ft ceiling?
,a. 800 ft3
b. 1,600 ft3
c. 2,400 ft3
d. 3,200 ft3
◉ b (1,200 CFM)
Answer: What is the CFM requirements for an 1,800-ft2 house with
8-ft ceilings, if five air changes per hour are needed?
a. 400 CFM
b. 1,200 CFM
c. 1,600 CFM
d. 2,400 CFM
◉ c (1,600 CFM)
Answer: What is the CFM requirement for an 2,400-ft2 house with 8-
ft ceilings, if five air changes per hour are needed?
a. 400 CFM
b. 1,200 CFM
c. 1,600 CFM
, d. 2,400 CFM
◉ a (79 in2)
Answer: What is the cross-sectional area of a 10-in round metal
duct?
a. 79 in2
b. 200 in2
c. 314 in2
d. 418 in2
Note: Area of a circle = π x radius^2
◉ d (1,800 ft/min)
Answer: How fast does air with a velocity pressure of 0.20 in. w.g.
move through a round duct?
a. 400 ft/min
b. 1,200 ft/min
c. 1,600 ft/min
d. 1,800 ft/min
