NATE heat pump exam questions with
correct answers
R-22 vapor line diameters and lengths are typically specified for a vapor pressure
drop that does not exceed - correct answer -6-7 psi or 6 degress F
The primary purpose of using flux when soldering copper or brass parts is to
prevent - correct answer -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 - correct answer -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 - correct answer -Curb gasket
When under a deep vacuum, a hermetic refrigeration compressor's motor windings
could be ________ if energized - correct answer -Damaged
In order for an evacuation to be considered complete, a heat pump refrigerant
circuit should be evacuated to a vacuum pressure of - correct answer -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 - correct answer -
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 -
correct answer -Shorter
To properly set a heat anticipator it is necessary to check the - correct answer -
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 - correct answer -Coil
TD (temperature difference)
The smallest refrigerant leak that an electronic leak detector should be capable of
sensing is - correct answer -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 - correct answer -
No effect
At sea level, a gauge pressure of 35 psig is equal to an absolute pressure of -
correct answer -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 - correct
answer -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
- correct answer -Replacing the diffuser
When performing preventive maintenance on a heat pump the technician should
check the outdoor fan to be certain that the fan - correct answer -runs freely with no
binding
What is the effect of 170 volts supplied to a 208/230 volt compressor would cause a
current - correct answer -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 - correct
answer -liquid line is restricted
A reason for cool air complaints when a heat pump is operating in the heating cycle
is - correct answer -excessive supply air velocities
correct answers
R-22 vapor line diameters and lengths are typically specified for a vapor pressure
drop that does not exceed - correct answer -6-7 psi or 6 degress F
The primary purpose of using flux when soldering copper or brass parts is to
prevent - correct answer -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 - correct answer -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 - correct answer -Curb gasket
When under a deep vacuum, a hermetic refrigeration compressor's motor windings
could be ________ if energized - correct answer -Damaged
In order for an evacuation to be considered complete, a heat pump refrigerant
circuit should be evacuated to a vacuum pressure of - correct answer -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 - correct answer -
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 -
correct answer -Shorter
To properly set a heat anticipator it is necessary to check the - correct answer -
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 - correct answer -Coil
TD (temperature difference)
The smallest refrigerant leak that an electronic leak detector should be capable of
sensing is - correct answer -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 - correct answer -
No effect
At sea level, a gauge pressure of 35 psig is equal to an absolute pressure of -
correct answer -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 - correct
answer -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
- correct answer -Replacing the diffuser
When performing preventive maintenance on a heat pump the technician should
check the outdoor fan to be certain that the fan - correct answer -runs freely with no
binding
What is the effect of 170 volts supplied to a 208/230 volt compressor would cause a
current - correct answer -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 - correct
answer -liquid line is restricted
A reason for cool air complaints when a heat pump is operating in the heating cycle
is - correct answer -excessive supply air velocities
