Nate Heat Pump
R-22 vapor line diameters and lengths are typically specified for a - ANS-Vapor pressure
drop that does not exceed 6 - 7 psi or 6°F
The primary purpose of using flux when soldering copper or brass parts is to -
ANS-Prevent oxidation
The water that results from a defrost cycle of an air to air heat pump (runoff) must -
ANS-Drain off and away from the outdoor coil to prevent excessive ice can build up on
the bottom of the coil and reduce capacity
The component used to reduce sound transmission and prevent water leaks of a
packaged heat pump installed on a roof is - ANS-The curb gasket
On some installations, a heat pump indoor coil can be installed on an existing, operable,
fossil fuel furnace.
When this type of installation is done you need to add a control so that - ANS-The
furnace and heat pump do not operate at the same time in normal heating
When under a deep vacuum, a hermetic refrigeration compressor's motor windings
could be - ANS-Damaged if energized
In order for an evacuation to be considered complete - ANS-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 - ANS-The total refrigerant charge for the
system would be
6 pounds
Drive slips are typically installed on the - ANS-Shorter sides of rectangular duct
To properly set a heat anticipator it is necessary to - ANS-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 -
ANS-This temperature difference is referred to as coil TD
The smallest refrigerant leak that an electronic leak detector should be capable of
sensing is - ANS-0.05 oz. per year
When checking the pressures in an operating system with a manifold gauge set -
ANS-Refrigerant oil in a hose will have no effect on the gauge reading
At sea level, a gauge pressure of 35 psig
is equal to an - ANS-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 - ANS-The CFM would be 1323
A residential supply diffuser that is noisy because of a loose vane is best serviced by -
ANS-Replacing the diffuser
When performing preventive maintenance on a heat pump the technician should check
the outdoor fan to be certain that the - ANS-Fan runs freely with no binding
What is the effect of 170 volts supplied to a 208/230 volt compressor - ANS-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 - ANS-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 -
ANS-Excessive supply air velocities
The following measurements are recorded on an operating heat pump system. The heat
pump is operating with the compressor only with no auxiliary heat
~Heat pump only supply air temperature 92°F
~Heat pump only return air temperature 70°F
~Outdoor temperature 54°F
~Supply air temp. /auxiliary heat ON 115°F
~Return air temp. /auxiliary heat ON 70°F
R-22 vapor line diameters and lengths are typically specified for a - ANS-Vapor pressure
drop that does not exceed 6 - 7 psi or 6°F
The primary purpose of using flux when soldering copper or brass parts is to -
ANS-Prevent oxidation
The water that results from a defrost cycle of an air to air heat pump (runoff) must -
ANS-Drain off and away from the outdoor coil to prevent excessive ice can build up on
the bottom of the coil and reduce capacity
The component used to reduce sound transmission and prevent water leaks of a
packaged heat pump installed on a roof is - ANS-The curb gasket
On some installations, a heat pump indoor coil can be installed on an existing, operable,
fossil fuel furnace.
When this type of installation is done you need to add a control so that - ANS-The
furnace and heat pump do not operate at the same time in normal heating
When under a deep vacuum, a hermetic refrigeration compressor's motor windings
could be - ANS-Damaged if energized
In order for an evacuation to be considered complete - ANS-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 - ANS-The total refrigerant charge for the
system would be
6 pounds
Drive slips are typically installed on the - ANS-Shorter sides of rectangular duct
To properly set a heat anticipator it is necessary to - ANS-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 -
ANS-This temperature difference is referred to as coil TD
The smallest refrigerant leak that an electronic leak detector should be capable of
sensing is - ANS-0.05 oz. per year
When checking the pressures in an operating system with a manifold gauge set -
ANS-Refrigerant oil in a hose will have no effect on the gauge reading
At sea level, a gauge pressure of 35 psig
is equal to an - ANS-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 - ANS-The CFM would be 1323
A residential supply diffuser that is noisy because of a loose vane is best serviced by -
ANS-Replacing the diffuser
When performing preventive maintenance on a heat pump the technician should check
the outdoor fan to be certain that the - ANS-Fan runs freely with no binding
What is the effect of 170 volts supplied to a 208/230 volt compressor - ANS-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 - ANS-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 -
ANS-Excessive supply air velocities
The following measurements are recorded on an operating heat pump system. The heat
pump is operating with the compressor only with no auxiliary heat
~Heat pump only supply air temperature 92°F
~Heat pump only return air temperature 70°F
~Outdoor temperature 54°F
~Supply air temp. /auxiliary heat ON 115°F
~Return air temp. /auxiliary heat ON 70°F
