NATE Air-to-Air Heat Pump
A good evacuation of a refrigerant circuit to remove non-condensable will
help ensure:
correct answers Higher efficiency and
Capacity.
A condensing unit should be mounted on a slab that is level to allow:
correct answers
Accumulated water to evenly run from the
cabin.
Low airflow over a residential split system air conditioning evaporator
can cause:
correct answers Liquid flood-back to the
compressor.
Which of the following is the correct sequence of work: correct answers
Attach manifold,
gauge the recover refrigerant, replace the filter core, evacuate
the system,
recharge the
system.
As the pressure on the liquid is increased, the vaporization temperature
of the liquid:
correct answers
Increases.
An oil-separator must be mounted: correct
answers Level.
Which of the following metering devices controls evaporator pressure:
None
correct ofanswers
these.
The purpose of the external equalizer on the thermostatic expansion valve
is: correct
answers To equalize evaporator pressure drop with respect to
the TEV.
The higher the MERV rating of a filter-drier, the: correct answers MERV does
notfilter-
to apply
driers.
Zeolite is used with: correct answers Refrigerant
filter driers.
Vacuum pressures are measured in: correct answers Microns, Millimeters or
Inches of
mercury
.
The number 25,400 relates to: correct answers
Microns/Inch.
A general rule of thumb for airflow: correct answers 400
CFM/Ton.
A double suction riser is used to: correct answers Improve oil return as
system capacity
changes
.
, A service technician measures a return air temperature of 80 degrees and
a supply air of 55 degrees. What, if anything, may be wrong with this air
temperature
residential
system split
air conditioning unit? correct answers Low airflow through
evaporator.
The normal compression ratio for a typical comfort air conditioning
application
in the rangeshould be answers 2.75 to
of: correct
3.75.
All else being normal, if a system shows a high, low-side superheat
with highersub-cooling, what is the most likely problem? correct
condenser
answers A partial
refrigerant
restriction.
All else being normal, if a system shows a low, low-side super heat
with a high sub-cooling, what is the likely problem? correct answers
condenser
Refrigerant
overcharg
e.
All else being normal, if a system shows a high, low-side superheat with low
condenser
sub cooling, what is most likely the problem? correct answers Refrigerant
undercharge.
A grille equipped with a damper control is called: correct answers
Register.
A pressure relief valve is... correct answers Direct
pressure acting.
A parallel compressor system in which both the crankcase oil level and
refrigerant
pressure aregas
equalized is a: correct answers Double pipe crankcase
equalizer system.
In a direct expansion chiller used on air conditioning applications, the
refrigerant
what side ofisthe
on tubes? correct answers Inside of
the tubes.
The total minimum open area for air to flow through on a supply air
registeranswers
correct is called:Free
area.
Which type of copper tubing has the thickest wall? correct
answers Type K.
What is the gross weight of a refrigerant cylinder? correct answers The
weight ofplus
cylinder the the weight of the
refrigerant.
What does an anemometer measure? correct answers Feet (time is a
separate
operation, automated for your
convenience).
The term induced draft most likely referes to... correct answers A type of
cooling tower.
What fitting should be used to connect 1/4" copper tuning to a 1/4" internal
pipe thread
opening on a compressor crankcase? correct answers
Half-union.
Which compressor has the fewest moving parts? correct
answers Scroll.
A good evacuation of a refrigerant circuit to remove non-condensable will
help ensure:
correct answers Higher efficiency and
Capacity.
A condensing unit should be mounted on a slab that is level to allow:
correct answers
Accumulated water to evenly run from the
cabin.
Low airflow over a residential split system air conditioning evaporator
can cause:
correct answers Liquid flood-back to the
compressor.
Which of the following is the correct sequence of work: correct answers
Attach manifold,
gauge the recover refrigerant, replace the filter core, evacuate
the system,
recharge the
system.
As the pressure on the liquid is increased, the vaporization temperature
of the liquid:
correct answers
Increases.
An oil-separator must be mounted: correct
answers Level.
Which of the following metering devices controls evaporator pressure:
None
correct ofanswers
these.
The purpose of the external equalizer on the thermostatic expansion valve
is: correct
answers To equalize evaporator pressure drop with respect to
the TEV.
The higher the MERV rating of a filter-drier, the: correct answers MERV does
notfilter-
to apply
driers.
Zeolite is used with: correct answers Refrigerant
filter driers.
Vacuum pressures are measured in: correct answers Microns, Millimeters or
Inches of
mercury
.
The number 25,400 relates to: correct answers
Microns/Inch.
A general rule of thumb for airflow: correct answers 400
CFM/Ton.
A double suction riser is used to: correct answers Improve oil return as
system capacity
changes
.
, A service technician measures a return air temperature of 80 degrees and
a supply air of 55 degrees. What, if anything, may be wrong with this air
temperature
residential
system split
air conditioning unit? correct answers Low airflow through
evaporator.
The normal compression ratio for a typical comfort air conditioning
application
in the rangeshould be answers 2.75 to
of: correct
3.75.
All else being normal, if a system shows a high, low-side superheat
with highersub-cooling, what is the most likely problem? correct
condenser
answers A partial
refrigerant
restriction.
All else being normal, if a system shows a low, low-side super heat
with a high sub-cooling, what is the likely problem? correct answers
condenser
Refrigerant
overcharg
e.
All else being normal, if a system shows a high, low-side superheat with low
condenser
sub cooling, what is most likely the problem? correct answers Refrigerant
undercharge.
A grille equipped with a damper control is called: correct answers
Register.
A pressure relief valve is... correct answers Direct
pressure acting.
A parallel compressor system in which both the crankcase oil level and
refrigerant
pressure aregas
equalized is a: correct answers Double pipe crankcase
equalizer system.
In a direct expansion chiller used on air conditioning applications, the
refrigerant
what side ofisthe
on tubes? correct answers Inside of
the tubes.
The total minimum open area for air to flow through on a supply air
registeranswers
correct is called:Free
area.
Which type of copper tubing has the thickest wall? correct
answers Type K.
What is the gross weight of a refrigerant cylinder? correct answers The
weight ofplus
cylinder the the weight of the
refrigerant.
What does an anemometer measure? correct answers Feet (time is a
separate
operation, automated for your
convenience).
The term induced draft most likely referes to... correct answers A type of
cooling tower.
What fitting should be used to connect 1/4" copper tuning to a 1/4" internal
pipe thread
opening on a compressor crankcase? correct answers
Half-union.
Which compressor has the fewest moving parts? correct
answers Scroll.
