NATE heat pump questions and answers 2025\2026
A+ Grade
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
A+ Grade
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
