NATE Air-to-Air Heat Pump Practice Test
2
A good evacuation of a refrigerant circuit to remove non-condensable will help ensure: - ✔✔ correct
answer Higher efficiency and Capacity.
A condensing unit should be mounted on a slab that is level to allow: - ✔✔ correct answer Accumulated
water to evenly run from the cabin.
Low airflow over a residential split system air conditioning evaporator can cause: - ✔✔ correct answer
Liquid flood-back to the compressor.
Which of the following is the correct sequence of work: - ✔✔ correct answer Attach the gauge manifold,
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
answer Increases.
An oil-separator must be mounted: - ✔✔ correct answer Level.
Which of the following metering devices controls evaporator pressure: - ✔✔ correct answer None of
these.
The purpose of the external equalizer on the thermostatic expansion valve is: - ✔✔ correct answer To
equalize evaporator pressure drop with respect to the TEV.
The higher the MERV rating of a filter-drier, the: - ✔✔ correct answer MERV does not apply to filter-
driers.
Zeolite is used with: - ✔✔ correct answer Refrigerant filter driers.
Vacuum pressures are measured in: - ✔✔ correct answer Microns, Millimeters or Inches of mercury.
, NATE Air-to-Air Heat Pump Practice Test
2
The number 25,400 relates to: - ✔✔ correct answer Microns/Inch.
A general rule of thumb for airflow: - ✔✔ correct answer 400 CFM/Ton.
A double suction riser is used to: - ✔✔ correct answer Improve oil return as system capacity changes.
A service technician measures a return air temperature of 80 degrees and a supply air temperature of 55
degrees. What, if anything, may be wrong with this air residential split system air conditioning unit? -
✔✔ correct answer Low airflow through evaporator.
The normal compression ratio for a typical comfort air conditioning application should be in the range of:
- ✔✔ correct answer 2.75 to 3.75.
All else being normal, if a system shows a high, low-side superheat with higher condenser sub-cooling,
what is the most likely problem? - ✔✔ correct answer A partial refrigerant restriction.
All else being normal, if a system shows a low, low-side super heat with a high condenser sub-cooling,
what is the likely problem? - ✔✔ correct answer Refrigerant overcharge.
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 answer Refrigerant undercharge.
A grille equipped with a damper control is called: - ✔✔ correct answer Register.
A pressure relief valve is... - ✔✔ correct answer Direct pressure acting.
A parallel compressor system in which both the crankcase oil level and refrigerant gas pressure are
equalized is a: - ✔✔ correct answer Double pipe crankcase equalizer system.
2
A good evacuation of a refrigerant circuit to remove non-condensable will help ensure: - ✔✔ correct
answer Higher efficiency and Capacity.
A condensing unit should be mounted on a slab that is level to allow: - ✔✔ correct answer Accumulated
water to evenly run from the cabin.
Low airflow over a residential split system air conditioning evaporator can cause: - ✔✔ correct answer
Liquid flood-back to the compressor.
Which of the following is the correct sequence of work: - ✔✔ correct answer Attach the gauge manifold,
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
answer Increases.
An oil-separator must be mounted: - ✔✔ correct answer Level.
Which of the following metering devices controls evaporator pressure: - ✔✔ correct answer None of
these.
The purpose of the external equalizer on the thermostatic expansion valve is: - ✔✔ correct answer To
equalize evaporator pressure drop with respect to the TEV.
The higher the MERV rating of a filter-drier, the: - ✔✔ correct answer MERV does not apply to filter-
driers.
Zeolite is used with: - ✔✔ correct answer Refrigerant filter driers.
Vacuum pressures are measured in: - ✔✔ correct answer Microns, Millimeters or Inches of mercury.
, NATE Air-to-Air Heat Pump Practice Test
2
The number 25,400 relates to: - ✔✔ correct answer Microns/Inch.
A general rule of thumb for airflow: - ✔✔ correct answer 400 CFM/Ton.
A double suction riser is used to: - ✔✔ correct answer Improve oil return as system capacity changes.
A service technician measures a return air temperature of 80 degrees and a supply air temperature of 55
degrees. What, if anything, may be wrong with this air residential split system air conditioning unit? -
✔✔ correct answer Low airflow through evaporator.
The normal compression ratio for a typical comfort air conditioning application should be in the range of:
- ✔✔ correct answer 2.75 to 3.75.
All else being normal, if a system shows a high, low-side superheat with higher condenser sub-cooling,
what is the most likely problem? - ✔✔ correct answer A partial refrigerant restriction.
All else being normal, if a system shows a low, low-side super heat with a high condenser sub-cooling,
what is the likely problem? - ✔✔ correct answer Refrigerant overcharge.
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 answer Refrigerant undercharge.
A grille equipped with a damper control is called: - ✔✔ correct answer Register.
A pressure relief valve is... - ✔✔ correct answer Direct pressure acting.
A parallel compressor system in which both the crankcase oil level and refrigerant gas pressure are
equalized is a: - ✔✔ correct answer Double pipe crankcase equalizer system.
