NYC Health HVAC Technician Exam
Practice Questions And Correct Answers
(Verified Answers) Plus Rationale 2026
Q&A| Instant Download Pdf
1. During a routine inspection of a hospital's central chilled water system,
an HVAC technician notices that the evaporator leaving-water
temperature is increasing while compressor amperage remains below
normal and suction pressure is unusually low. Which condition is the
most likely cause of these combined symptoms?
A. Overcharged refrigerant system causing high condenser pressure
B. Condenser water flow is excessive
C. Refrigerant undercharge or significant refrigerant leak
D. Expansion valve stuck fully open
Rationale: A refrigerant undercharge commonly results in low suction
pressure, reduced evaporator capacity, low compressor load, and warmer
,chilled water temperatures. An overcharged system generally produces
higher head pressure and increased compressor loading rather than the
observed conditions.
2. A hospital HVAC technician is assigned to troubleshoot a variable air
volume (VAV) air-handling unit serving patient rooms. Several rooms
report insufficient airflow, yet the supply fan is operating normally and
the building automation system indicates that static pressure is below
the setpoint. What should be the technician's first corrective action?
A. Replace all VAV box actuators immediately.
B. Increase chilled water flow to the cooling coil.
C. Inspect the supply duct system, static pressure sensor, and fan control
sequence before replacing components.
D. Close all return air dampers.
Rationale: Low static pressure may result from duct leakage, faulty
sensors, improper fan speed control, or open dampers. A systematic
diagnosis prevents unnecessary replacement of functioning equipment.
3. A centrifugal fan operating in a hospital air-handling unit develops
excessive vibration shortly after a new motor installation. Which
condition should the technician investigate first?
A. Dirty air filters only
B. Improper motor and fan shaft alignment or incorrect belt tension
,C. Low refrigerant charge
D. Closed chilled water valve
Rationale: Misalignment and improper belt tension are common causes of
excessive vibration after motor replacement. Correct alignment extends
bearing life and improves equipment reliability.
4. In a hospital operating room, maintaining positive air pressure is
primarily intended to:
A. Reduce building energy consumption.
B. Prevent excessive humidity.
C. Prevent contaminants from entering the operating room from adjacent
spaces.
D. Increase return air velocity.
Rationale: Positive pressure ensures clean filtered air flows outward
whenever doors are opened, reducing the likelihood of airborne
contaminants entering sterile environments.
5. A technician observes frost forming only near the inlet of an
evaporator coil while the remainder of the coil remains warm. Which
condition most likely explains this observation?
A. Overcharged refrigeration system
B. High condenser water temperature
C. Restricted refrigerant flow caused by a partially blocked metering device
, or filter-drier
D. Excessive airflow across the evaporator
Rationale: A refrigerant restriction causes rapid pressure reduction near
the inlet, producing localized freezing while the remainder of the
evaporator receives insufficient refrigerant.
6. Which instrument is most appropriate for accurately measuring the
velocity of conditioned air leaving a supply diffuser?
A. Clamp-on ammeter
B. Micrometer
C. Refrigerant scale
D. Anemometer
Rationale: An anemometer is specifically designed to measure air velocity,
allowing technicians to calculate airflow and verify system performance.
7. The primary purpose of a condensate trap installed on the drain line of
a draw-through air-handling unit is to:
A. Increase refrigerant pressure.
B. Lubricate the condensate pump.
C. Prevent air from being drawn into the drain line while allowing
condensate to drain properly.
D. Increase cooling capacity.
Practice Questions And Correct Answers
(Verified Answers) Plus Rationale 2026
Q&A| Instant Download Pdf
1. During a routine inspection of a hospital's central chilled water system,
an HVAC technician notices that the evaporator leaving-water
temperature is increasing while compressor amperage remains below
normal and suction pressure is unusually low. Which condition is the
most likely cause of these combined symptoms?
A. Overcharged refrigerant system causing high condenser pressure
B. Condenser water flow is excessive
C. Refrigerant undercharge or significant refrigerant leak
D. Expansion valve stuck fully open
Rationale: A refrigerant undercharge commonly results in low suction
pressure, reduced evaporator capacity, low compressor load, and warmer
,chilled water temperatures. An overcharged system generally produces
higher head pressure and increased compressor loading rather than the
observed conditions.
2. A hospital HVAC technician is assigned to troubleshoot a variable air
volume (VAV) air-handling unit serving patient rooms. Several rooms
report insufficient airflow, yet the supply fan is operating normally and
the building automation system indicates that static pressure is below
the setpoint. What should be the technician's first corrective action?
A. Replace all VAV box actuators immediately.
B. Increase chilled water flow to the cooling coil.
C. Inspect the supply duct system, static pressure sensor, and fan control
sequence before replacing components.
D. Close all return air dampers.
Rationale: Low static pressure may result from duct leakage, faulty
sensors, improper fan speed control, or open dampers. A systematic
diagnosis prevents unnecessary replacement of functioning equipment.
3. A centrifugal fan operating in a hospital air-handling unit develops
excessive vibration shortly after a new motor installation. Which
condition should the technician investigate first?
A. Dirty air filters only
B. Improper motor and fan shaft alignment or incorrect belt tension
,C. Low refrigerant charge
D. Closed chilled water valve
Rationale: Misalignment and improper belt tension are common causes of
excessive vibration after motor replacement. Correct alignment extends
bearing life and improves equipment reliability.
4. In a hospital operating room, maintaining positive air pressure is
primarily intended to:
A. Reduce building energy consumption.
B. Prevent excessive humidity.
C. Prevent contaminants from entering the operating room from adjacent
spaces.
D. Increase return air velocity.
Rationale: Positive pressure ensures clean filtered air flows outward
whenever doors are opened, reducing the likelihood of airborne
contaminants entering sterile environments.
5. A technician observes frost forming only near the inlet of an
evaporator coil while the remainder of the coil remains warm. Which
condition most likely explains this observation?
A. Overcharged refrigeration system
B. High condenser water temperature
C. Restricted refrigerant flow caused by a partially blocked metering device
, or filter-drier
D. Excessive airflow across the evaporator
Rationale: A refrigerant restriction causes rapid pressure reduction near
the inlet, producing localized freezing while the remainder of the
evaporator receives insufficient refrigerant.
6. Which instrument is most appropriate for accurately measuring the
velocity of conditioned air leaving a supply diffuser?
A. Clamp-on ammeter
B. Micrometer
C. Refrigerant scale
D. Anemometer
Rationale: An anemometer is specifically designed to measure air velocity,
allowing technicians to calculate airflow and verify system performance.
7. The primary purpose of a condensate trap installed on the drain line of
a draw-through air-handling unit is to:
A. Increase refrigerant pressure.
B. Lubricate the condensate pump.
C. Prevent air from being drawn into the drain line while allowing
condensate to drain properly.
D. Increase cooling capacity.
