NATE Heat Pump
R-22 vapor line diameters and lengths are typically specified for a vapor pressure drop that
does not exceed... - ANS6-7 psi or 6°F
The primary purpose of using flux when soldering copper or brass parts is to... - ANSPrevent
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... - ANSPrevent excessive ice can build up on the bottom of the
coil and reduce capacity
The component used to reduce sound transmission and regent water leaks of a packaged heat
pump installed on a roof is... - ANSThe 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... - ANSAdd a control so that 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... -
ANSBe damaged if energized
In order for evacuation to be considered complete, a heat pump refrigerant circuit should be
evacuated to a vacuum pressure of... - ANS500 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 o be 5 pounds 10oz. The line set uses a 3/8 inch liquid line and is 25
feet long. The manufacturer's instruction she specifies 0.6 oz of refrigerant to be added for... -
ANSeach added foot of refrigerant line length so the total regrigerrant charge for the system
would be 6 pounds
Drive slips are typically installed on... - ANSthe shorter sides of rectangular duct
To properly set a heat anticipator it is necessary to check... - ANSthe 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... - ANScoil TD
The smallest refrigerant leak that an electronic leak detector should be capable of sensing is... -
ANS0.05 oz. per year
, When checking the pressure in an operating system with a manifold gauge set... -
ANSrefrigerant oil in a hose will have no effect on the gauge reading
At sea level a gauge pressure of 35 psig is equal to ... - ANSan 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... - ANS1323
A residential supply diffuser that is noisy because of a loose vane is best serviced by... -
ANSreplacing the filter
When performing preventive maintenance on a heat pump the technician should... - ANScheck
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 ... - ANSwould cause a
current increase and the motor may trip on overload
On a service call for a cooling problem with a heat pump, your inspection find a liquid line that
has condensation on it. The most likely cause would be... - ANSthe liquid linen is restricted
A reason for cool air complaints when a heat pump is operating in the heating cycle is... -
ANSexcessive 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 / aux heat on 115(F)
- Return air temp / auxillary heat on 70(F)
- CFM 1228
The heating capacity of the unit in BTUh would be... - ANS29,177 BTUh
A dirty or clogged air filter in an operating heat pump system can... - ANSbe caused by
inadequate heating
To minimize noise problems in residential duct systems, what is the range (recommended to
maximum) of design air velocity in the rectangular main supply trunk... - ANSis 700 to 900 fpm
Proper ductwork connections and sealing is critical to good system performance...
Conditions are:
- Return side air leak of 15% in a ventilated attic
R-22 vapor line diameters and lengths are typically specified for a vapor pressure drop that
does not exceed... - ANS6-7 psi or 6°F
The primary purpose of using flux when soldering copper or brass parts is to... - ANSPrevent
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... - ANSPrevent excessive ice can build up on the bottom of the
coil and reduce capacity
The component used to reduce sound transmission and regent water leaks of a packaged heat
pump installed on a roof is... - ANSThe 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... - ANSAdd a control so that 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... -
ANSBe damaged if energized
In order for evacuation to be considered complete, a heat pump refrigerant circuit should be
evacuated to a vacuum pressure of... - ANS500 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 o be 5 pounds 10oz. The line set uses a 3/8 inch liquid line and is 25
feet long. The manufacturer's instruction she specifies 0.6 oz of refrigerant to be added for... -
ANSeach added foot of refrigerant line length so the total regrigerrant charge for the system
would be 6 pounds
Drive slips are typically installed on... - ANSthe shorter sides of rectangular duct
To properly set a heat anticipator it is necessary to check... - ANSthe 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... - ANScoil TD
The smallest refrigerant leak that an electronic leak detector should be capable of sensing is... -
ANS0.05 oz. per year
, When checking the pressure in an operating system with a manifold gauge set... -
ANSrefrigerant oil in a hose will have no effect on the gauge reading
At sea level a gauge pressure of 35 psig is equal to ... - ANSan 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... - ANS1323
A residential supply diffuser that is noisy because of a loose vane is best serviced by... -
ANSreplacing the filter
When performing preventive maintenance on a heat pump the technician should... - ANScheck
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 ... - ANSwould cause a
current increase and the motor may trip on overload
On a service call for a cooling problem with a heat pump, your inspection find a liquid line that
has condensation on it. The most likely cause would be... - ANSthe liquid linen is restricted
A reason for cool air complaints when a heat pump is operating in the heating cycle is... -
ANSexcessive 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 / aux heat on 115(F)
- Return air temp / auxillary heat on 70(F)
- CFM 1228
The heating capacity of the unit in BTUh would be... - ANS29,177 BTUh
A dirty or clogged air filter in an operating heat pump system can... - ANSbe caused by
inadequate heating
To minimize noise problems in residential duct systems, what is the range (recommended to
maximum) of design air velocity in the rectangular main supply trunk... - ANSis 700 to 900 fpm
Proper ductwork connections and sealing is critical to good system performance...
Conditions are:
- Return side air leak of 15% in a ventilated attic
