NYC Health + Hospitals Senior HVAC
Technician Examination Practice Exam
2026 | 100 Questions & Answers with
Detailed Rationales | Complete Exam
Prep & Study Guide
1. What is the primary purpose of a refrigeration compressor?
A. Remove moisture from the air
B. Raise the pressure and temperature of refrigerant vapor
C. Reduce condenser pressure
D. Meter liquid refrigerant
Answer: Raise the pressure and temperature of refrigerant vapor
Rationale: The compressor takes low-pressure refrigerant vapor from the
evaporator and compresses it into a high-pressure, high-temperature vapor for
the condenser.
2. Which component meters refrigerant into an evaporator?
A. Receiver
B. Accumulator
C. Expansion valve
D. Condenser
Answer: Expansion valve
,Rationale: The expansion valve regulates refrigerant flow into the evaporator
and creates the pressure drop needed for evaporation.
3. What is the main function of a condenser?
A. Absorb heat from the conditioned space
B. Increase evaporator pressure
C. Reject heat from the refrigerant
D. Meter refrigerant
Answer: Reject heat from the refrigerant
Rationale: The condenser removes heat from high-pressure refrigerant vapor,
causing it to condense into a liquid.
4. What condition generally indicates insufficient evaporator airflow?
A. Low head pressure only
B. Low suction pressure and possible evaporator icing
C. High suction pressure
D. Increased airflow
Answer: Low suction pressure and possible evaporator icing
Rationale: Restricted airflow reduces the heat available to the evaporator,
which can lower suction pressure and cause coil temperatures to fall below
freezing.
5. What does superheat measure?
A. Liquid temperature below saturation
B. Condenser temperature
C. Vapor temperature above its saturation temperature
D. Compressor oil temperature only
Answer: Vapor temperature above its saturation temperature
,Rationale: Superheat is the difference between actual refrigerant vapor
temperature and its saturation temperature at a given pressure.
6. What does subcooling indicate?
A. Vapor temperature above saturation
B. Liquid temperature below its saturation temperature
C. Compressor discharge temperature
D. Air temperature below freezing
Answer: Liquid temperature below its saturation temperature
Rationale: Subcooling is the temperature difference between saturated liquid
temperature and the actual liquid refrigerant temperature.
7. A dirty condenser coil will most commonly cause:
A. Lower condensing pressure
B. Higher condensing pressure
C. Lower discharge temperature
D. Increased condenser airflow
Answer: Higher condensing pressure
Rationale: Dirt restricts heat transfer from the condenser, causing refrigerant
temperature and condensing pressure to rise.
8. What is the purpose of a filter-drier?
A. Increase compressor capacity
B. Remove moisture and contaminants from the refrigerant system
C. Increase suction pressure
D. Add refrigerant oil
Answer: Remove moisture and contaminants from the refrigerant system
Rationale: Filter-driers protect refrigeration components by trapping debris and
absorbing moisture that can cause corrosion, freezing, or chemical damage.
, 9. What is the purpose of an accumulator in a refrigeration system?
A. Store condenser water
B. Increase liquid pressure
C. Prevent liquid refrigerant from entering the compressor
D. Remove air from ductwork
Answer: Prevent liquid refrigerant from entering the compressor
Rationale: An accumulator temporarily holds excess liquid refrigerant and helps
ensure that primarily vapor reaches the compressor.
10.What type of compressor uses pistons moving inside cylinders?
A. Scroll
B. Screw
C. Centrifugal
D. Reciprocating
Answer: Reciprocating
Rationale: Reciprocating compressors use pistons and cylinders to compress
refrigerant vapor.
11.Which compressor uses two spiral-shaped scrolls?
A. Reciprocating
B. Screw
C. Scroll
D. Centrifugal
Answer: Scroll
Rationale: A scroll compressor compresses refrigerant using orbiting and
stationary scroll members.
12.What is the purpose of an evaporator?