NATE Heat Pump Exam 2024 Questions with
100% Correct Answers
R-22 vapor line diameters and lengths are typically specified for a vapor pressure drop that does not
exceed
6-7 psi or 6 degress F
The primary purpose of using flux when soldering copper or brass parts is to prevent
Oxidation
The water that results from a defrost cycle of an air to air heat pump (runoff) must drain off and away
from the outdoor coil to prevent
Excessive ice build up
The component used to reduce sound transmission and prevent water leaks of a packaged heat pump
installed on a roof is the
Curb gasket
When under a deep vacuum, a hermetic refrigeration compressor's motor windings could be
________ if energized
Damaged
In order for an evacuation to be considered complete, a heat pump refrigerant circuit should be
evacuated to a vacuum pressure of
500 microns or below
A system is supplied from the factory with charge for a 15 foot line set. The data plate shows the
required system charge to be 5 pounds 10 ounces. The line set uses a 3/8 inch liquid line and is 25
feet long. The manufacturer's instruction sheet specifies 0.6 ounces of refrigerant to be added for
each added foot of refrigerant line length so the total refrigerant charge for the system would be
6 lbs(25-15=10 10x0.6=6oz 6oz+5lbs 10oz= 5lbs 16oz the equilvalent of 6lbs)
Drive slips are typically installed on the __________ sides of rectangular ducts
Shorter
To properly set a heat anticipator it is necessary to check the
heating control circuit amperage draw
A heat pump operating in normal ice free conditions maintains a certain temperature difference
between the outdoor coil temperature and the surrounding outdoor ambient. This temperature
difference is referred to as
Coil TD (temperature difference)
The smallest refrigerant leak that an electronic leak detector should be capable of sensing is
0.05 oz. per year
, When checking the pressures in an operating system with a manifold gauge set, refrigerant oil in a
hose will have ___ ______ on the gauge reading
No effect
At sea level, a gauge pressure of 35 psig is equal to an absolute pressure of
49.7 psia
A technician measures the return air temperature of a 100,000 Btu output furnace to be 65°F and the
supply side air temperature is 135°F. The CFM would be
1323 (TD= 135-65=70➡️100,000/TDx1.08 ➡️100,000/75.6=1323)
A residential supply diffuser that is noisy because of a loose vane is best serviced by
Replacing the diffuser
When performing preventive maintenance on a heat pump the technician should check the outdoor
fan to be certain that the fan
runs freely with no binding
What is the effect of 170 volts supplied to a 208/230 volt compressor would cause a current
increase and the motor may trip on overload
On a service call for a cooling problem with a heat pump, your inspections find a liquid line that has
condensation on it. The most likely cause would be the
liquid line is restricted
A reason for cool air complaints when a heat pump is operating in the heating cycle is
excessive supply air velocities
A dirty or clogged air filter in an operating heat pump system can cause
inadequate heating
To minimize noise problems in residential duct systems, the range (recommended to maximum) of
design air velocity in the rectangular main supply trunk is
700 to 900 fpm
The effect of adding a charge to sub cooling is
it increases it
When a capillary tube is overcharged you would get a ____ superheat and ____ sub cooling
Low,high
The effect of a low charge on the switchover operations of a reversing valve is
the reversing valves are less likely to transfer
100% Correct Answers
R-22 vapor line diameters and lengths are typically specified for a vapor pressure drop that does not
exceed
6-7 psi or 6 degress F
The primary purpose of using flux when soldering copper or brass parts is to prevent
Oxidation
The water that results from a defrost cycle of an air to air heat pump (runoff) must drain off and away
from the outdoor coil to prevent
Excessive ice build up
The component used to reduce sound transmission and prevent water leaks of a packaged heat pump
installed on a roof is the
Curb gasket
When under a deep vacuum, a hermetic refrigeration compressor's motor windings could be
________ if energized
Damaged
In order for an evacuation to be considered complete, a heat pump refrigerant circuit should be
evacuated to a vacuum pressure of
500 microns or below
A system is supplied from the factory with charge for a 15 foot line set. The data plate shows the
required system charge to be 5 pounds 10 ounces. The line set uses a 3/8 inch liquid line and is 25
feet long. The manufacturer's instruction sheet specifies 0.6 ounces of refrigerant to be added for
each added foot of refrigerant line length so the total refrigerant charge for the system would be
6 lbs(25-15=10 10x0.6=6oz 6oz+5lbs 10oz= 5lbs 16oz the equilvalent of 6lbs)
Drive slips are typically installed on the __________ sides of rectangular ducts
Shorter
To properly set a heat anticipator it is necessary to check the
heating control circuit amperage draw
A heat pump operating in normal ice free conditions maintains a certain temperature difference
between the outdoor coil temperature and the surrounding outdoor ambient. This temperature
difference is referred to as
Coil TD (temperature difference)
The smallest refrigerant leak that an electronic leak detector should be capable of sensing is
0.05 oz. per year
, When checking the pressures in an operating system with a manifold gauge set, refrigerant oil in a
hose will have ___ ______ on the gauge reading
No effect
At sea level, a gauge pressure of 35 psig is equal to an absolute pressure of
49.7 psia
A technician measures the return air temperature of a 100,000 Btu output furnace to be 65°F and the
supply side air temperature is 135°F. The CFM would be
1323 (TD= 135-65=70➡️100,000/TDx1.08 ➡️100,000/75.6=1323)
A residential supply diffuser that is noisy because of a loose vane is best serviced by
Replacing the diffuser
When performing preventive maintenance on a heat pump the technician should check the outdoor
fan to be certain that the fan
runs freely with no binding
What is the effect of 170 volts supplied to a 208/230 volt compressor would cause a current
increase and the motor may trip on overload
On a service call for a cooling problem with a heat pump, your inspections find a liquid line that has
condensation on it. The most likely cause would be the
liquid line is restricted
A reason for cool air complaints when a heat pump is operating in the heating cycle is
excessive supply air velocities
A dirty or clogged air filter in an operating heat pump system can cause
inadequate heating
To minimize noise problems in residential duct systems, the range (recommended to maximum) of
design air velocity in the rectangular main supply trunk is
700 to 900 fpm
The effect of adding a charge to sub cooling is
it increases it
When a capillary tube is overcharged you would get a ____ superheat and ____ sub cooling
Low,high
The effect of a low charge on the switchover operations of a reversing valve is
the reversing valves are less likely to transfer
