HVAC NATE Heat Pump
On an R-22 system, line diameters and lengths are typically specified
for a vapor
pressure drop that does not exceed what? correct answers 6-
7PSI or 6F
What is the primary purpose of using flux when soldering copper or
brass parts?
correct answers Prevent
Oxidation
The water that results from a defrost cycle of an air to air heat
pump(runoff)
correct answers must?
Drain off and away from the
outdoor coil.
Why must the runoff be drained off and away from the outdoor coil?
correct answers
Excessive ice can build up on the bottom of the coil and can reduce
capacity.
What is the component that reduces sound transmission and prevents
water leaks
package heat of pump
a installed on a roof? correct answers
Curb Gasket
Why do you need to add a control for a heat pump indoor coil that is
installed
fuel on a fossil
furnace? correct answers So the heat pump and furnace do not
operate
same at the
time in normal
heating.
What happens when you energize a hermetic refrigeration compressor and
the
is insystem
a deep vacuum? correct answers Motor windings could become
damaged.
What needs to happen in order to consider an evacuation to be
complete?
answers correct
System should be evacuated to a vacuum of 500 Microns
or below.
A system is supplied from the factory with charge for a 15 foot line set.
The data
shows theplate
required system charge to be 5 pounds 10 ounces. The line set
uses liquid
inch a 3/8 line and is 25 feet long. The manufacturer's instruction sheet
ounces
specifiesof0.6
refrigerant to be added for each added foot of refrigerant line
length.refrigerant
much How is needed to completely charge the system? correct
answers 6lbs
Where are drive slips typically installed? correct answers On the
shorter sides of
rectangular
duct.
What is a necessary check to properly set a heat anticipator? correct
answerscircuit
control Heating
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
What ambient.
is this temperature referred to as? correct answers
Coil TD.
, What is the smallest refrigerant leak that an electronic leak detector should
be sensing?
of capable correct answers .o5oz per
year.
When checking the pressures in an operating system with a manifold
gauge set, will
refrigerant oil in a hose will have an effect on the gauge? correct
answers No
What is the absolute pressure at sea level if a gauge pressure is 35
psig? correct
answers
49.7psia
100,000 BTUH output
furnace.
Return air temp is
65F.
Supply air is
135F.
What is the CFM? correct answers
1323CFM
What is the best method of repair when a residential supply diffuser is noisy
because
a of
loose vane? correct answers Replace the
diffuser.
When performing preventive maintenance on a heat pump what should the
technician
check and why? correct answers Outdoor fan. To be certain it runs
freely with no
bindin
g.
What is the effect of 170 volts supplied to a 208/230 volt compressor?
correctcause
Would answers
the current to increase and the motor may trip on
overload.
On a service call for a cooling problem with a heat pump, your inspections
find that
line a liquid
has condensation on it. What is most likely to cause this?
correct answers
Restriction in the liquid
line.
What is a reason for cool air complaints when a heat pump is operating in
the heating
cycle? correct answers Excessive supply air
velocities.
The following measurements are recorded on an operating heat pump
system.
pump is The heat with the compressor only with no
operating
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
• CFM
1228
On an R-22 system, line diameters and lengths are typically specified
for a vapor
pressure drop that does not exceed what? correct answers 6-
7PSI or 6F
What is the primary purpose of using flux when soldering copper or
brass parts?
correct answers Prevent
Oxidation
The water that results from a defrost cycle of an air to air heat
pump(runoff)
correct answers must?
Drain off and away from the
outdoor coil.
Why must the runoff be drained off and away from the outdoor coil?
correct answers
Excessive ice can build up on the bottom of the coil and can reduce
capacity.
What is the component that reduces sound transmission and prevents
water leaks
package heat of pump
a installed on a roof? correct answers
Curb Gasket
Why do you need to add a control for a heat pump indoor coil that is
installed
fuel on a fossil
furnace? correct answers So the heat pump and furnace do not
operate
same at the
time in normal
heating.
What happens when you energize a hermetic refrigeration compressor and
the
is insystem
a deep vacuum? correct answers Motor windings could become
damaged.
What needs to happen in order to consider an evacuation to be
complete?
answers correct
System should be evacuated to a vacuum of 500 Microns
or below.
A system is supplied from the factory with charge for a 15 foot line set.
The data
shows theplate
required system charge to be 5 pounds 10 ounces. The line set
uses liquid
inch a 3/8 line and is 25 feet long. The manufacturer's instruction sheet
ounces
specifiesof0.6
refrigerant to be added for each added foot of refrigerant line
length.refrigerant
much How is needed to completely charge the system? correct
answers 6lbs
Where are drive slips typically installed? correct answers On the
shorter sides of
rectangular
duct.
What is a necessary check to properly set a heat anticipator? correct
answerscircuit
control Heating
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
What ambient.
is this temperature referred to as? correct answers
Coil TD.
, What is the smallest refrigerant leak that an electronic leak detector should
be sensing?
of capable correct answers .o5oz per
year.
When checking the pressures in an operating system with a manifold
gauge set, will
refrigerant oil in a hose will have an effect on the gauge? correct
answers No
What is the absolute pressure at sea level if a gauge pressure is 35
psig? correct
answers
49.7psia
100,000 BTUH output
furnace.
Return air temp is
65F.
Supply air is
135F.
What is the CFM? correct answers
1323CFM
What is the best method of repair when a residential supply diffuser is noisy
because
a of
loose vane? correct answers Replace the
diffuser.
When performing preventive maintenance on a heat pump what should the
technician
check and why? correct answers Outdoor fan. To be certain it runs
freely with no
bindin
g.
What is the effect of 170 volts supplied to a 208/230 volt compressor?
correctcause
Would answers
the current to increase and the motor may trip on
overload.
On a service call for a cooling problem with a heat pump, your inspections
find that
line a liquid
has condensation on it. What is most likely to cause this?
correct answers
Restriction in the liquid
line.
What is a reason for cool air complaints when a heat pump is operating in
the heating
cycle? correct answers Excessive supply air
velocities.
The following measurements are recorded on an operating heat pump
system.
pump is The heat with the compressor only with no
operating
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
• CFM
1228
