NATE Air Conditioning and Heat Pump Questions With Correct Answers(Guaranteed Success)
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Course
NATE
Institution
NATE
NATE Air Conditioning and Heat Pump Questions With Correct Answers(Guaranteed Success)
Which of the following factors affects a customers level of comfort? - correct answer...All of the above
A cooling load calculation estimates the sensible heat gain of the structure. The cooling-only system...
NATE Air Conditioning and Heat Pump
Questions With Correct
Answers(Guaranteed Success)
Which of the following factors affects a customers level of comfort? - correct
answer...✔✔All of the above
A cooling load calculation estimates the sensible heat gain of the structure. The cooling-
only system should be within _____% of this calculated value. - correct answer...✔✔
+15%
The maximum sensible cooling capacity of a heat pump should be within ______% of
the calculated sensible heat gain of a structure with a large heating load. - correct
answer...✔✔+25%
The combined output of a heatpump and its auxiliary heat should not exceed the
calculated heat loss of a home by more than ____%. - correct answer...✔✔15%
What amount of auxiliary electronic heat is needed when the output of a heat pump on a
design day equals 18,800 Btuh and the heat loss of a home is 29,700 Btuh? - correct
answer...✔✔3.2 kWh
The three processes that transfer heat energy are conduction, convection, and
_________. - correct answer...✔✔Radiation
Heat transfer that occurs when substances of different temperatures are in contact with
each other is called _______. - correct answer...✔✔conduction
What effect does raising the pressure in a sealed system have on refrigerant? - correct
answer...✔✔The boiling point increases
What is the primary danger to people near an accidental refrigerant release or spill? -
correct answer...✔✔suffocation caused by the heavier refrigerant displacing oxygen in
the air
The maximum temperature at which refrigerant may be stored is ______ F when the
container is no more than ____% full of liquid by volume.; - correct answer...✔✔125 F,
80%
Boiling of the refrigerant occurs in which system component? - correct answer...✔✔
Evaporator
AGRADESOLUTIONS
,Why is superheat necessary in a system that utilizes hermetic compressors - correct
answer...✔✔It ensures that dry vapor reaches the compressor so that mechanical
damage does not occur
When the heat load on an evaporator increases, what is the effect on the system? -
correct answer...✔✔Suction pressure and discharge pressure both increase
What type of energy is transferred when work is done in the condenser? - correct
answer...✔✔Both latent and sensible heat energy
What is the primary function performed by a thermal expansion valve? - correct
answer...✔✔It maintains the correct superheat in the suction vapor leaving the
evaporator
Which component pumps refrigerant through the system and raises the vapor
temperature? - correct answer...✔✔compressor
How are hermetic compressor motors cooled? - correct answer...✔✔With suction vapor
drawn from the evaporator
Heat pump compressors sometimes run hotter than compressors used in cooling-only
units because heat pump compressors _____. - correct answer...✔✔exhibit low
refrigerant density at low suction pressures during the heating cycle
When is crankcase heat most needed? - correct answer...✔✔When the compressor is
off
Work done on the refrigerant in the condenser is transferred as ____. - correct answer...
✔✔Both sensible and latent heat
Why are more circuits needed in the outdoor coils used in heat pumps than in the
condenser coils used in cooling-only units? - correct answer...✔✔To keep the pressure
drop across the outdoor coil low
What is they typical water flow rate per ton of cooling for water-source heat pumps
operating in closed loop systems? - correct answer...✔✔3.0 gpm per ton
What tool should be used to shorten a capillary tube? - correct answer...✔✔A triangular
or knife-edge file
Which pressure in a TEV is opening pressure? - correct answer...✔✔bulb pressure
What effect does a low refrigerant charge have on reversing valve operations? - correct
answer...✔✔It increases the chance that the reversing valve will not be able to transfer
properly
AGRADESOLUTIONS
, When adding a heat pump to an existing fossil-fuel furnace, an installer must do all of
the following except ______. - correct answer...✔✔Make sure that the new number of
fins per inch of the new coils equals that of the replaced coils
What is the purpose of a receiver? - correct answer...✔✔It store liquid refrigerant
What is the typical storage life of modern refrigerants? - correct answer...✔✔Modern
refrigerants have an indefinite storage life
Which of the following should be used to leak-test refrigerant tubing? - correct answer...
✔✔Dry Nitrogen
Of the motors commonly used in HVACR systems, which type has the lowest starting
torque? - correct answer...✔✔Shaded-pole motor
What is the typical phase angle for a split-phase motor? - correct answer...✔✔30
What determines the staging of a two-speed compressor in a heat pump application? -
correct answer...✔✔Deviation from setpoint of the thermostat
The NEC approves a _____ dual-element time-delay fuse as overcurrent protection for
a 20 A motor. - correct answer...✔✔60-A
Voltage supplied to a motor may vary from the rated voltage by _____%. - correct
answer...✔✔+10%,-10%
What is one of the most Important reasons for using electronic controls in HVACR
systems? - correct answer...✔✔they make decisions based on many inputs
Hard-start kits are often needed on ______. - correct answer...✔✔reciprocating
compressors used with TEVs
A 24-V transformer with a 40-VA rating can operate safely with a current of _____. -
correct answer...✔✔1.67 A
Some electromechanical thermostats must be connected to both sides of the
transformer in order to power the _______. - correct answer...✔✔display lights on the
subbase
A cooling anticipator in the control circuits is connected in _____ with the _____ switch
of the thermostat. - correct answer...✔✔parallel, cooling
According to Ohm's Law, what will happen if the voltage to a heater element is
increased by 10%? - correct answer...✔✔The current draw will increase by 10%
AGRADESOLUTIONS
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