TEXAS INDUSTRIAL HVAC CERTIFICATION
EXAM WITH ACTUAL QUESTIONS AND
VERIFIED ANSWERS, PLUS EXPLAINED
RATIONALES/EXPERT VERIFIED FOR
GUARANTEED 100% PASS 2026/LATEST
UPDATE/INSTANT DOWNLOAD PDF
1. In a large industrial chilled water system, the primary purpose of
installing variable frequency drives (VFDs) on centrifugal pump
motors is to:
A. Increase refrigerant pressure
B. Reduce motor speed to match system demand while improving
efficiency
C. Increase pump discharge pressure regardless of load
D. Prevent water hammer by increasing flow
Answer: B. Reduce motor speed to match system demand while
improving efficiency
Rationale: VFDs adjust motor speed according to system demand,
significantly reducing energy consumption because pump power varies
approximately with the cube of speed. Industrial HVAC systems
commonly utilize VFDs to maintain differential pressure while
minimizing electrical costs.
2. A technician measures 480V across a three-phase motor but finds
the motor is not operating. The first electrical measurement should
be:
A. Refrigerant pressure
B. Amp draw with the disconnect open
1
,C. Voltage at each winding and continuity through the overloads
D. Water temperature
Answer: C. Voltage at each winding and continuity through the
overloads
Rationale: Adequate line voltage does not guarantee power reaches the
motor windings. Open overloads, failed contactors, or damaged
windings can interrupt current flow despite correct supply voltage.
3. During compressor analysis, excessively high discharge
temperatures primarily indicate:
A. Floodback
B. Low compression ratio
C. High compression ratio or insufficient suction cooling
D. Excessive oil level
Answer: C. High compression ratio or insufficient suction cooling
Rationale: High compression ratios significantly increase discharge
temperatures. Low suction pressure, dirty condensers, non-
condensables, or inadequate suction gas cooling can all contribute.
4. Which psychrometric process occurs when air passes over a
cooling coil operating below the dew point?
A. Sensible heating
B. Sensible cooling only
C. Sensible cooling and latent cooling
D. Humidification
Answer: C. Sensible cooling and latent cooling
2
,Rationale: When coil temperature falls below the dew point, moisture
condenses from the air while temperature decreases, producing both
sensible and latent heat removal.
5. Oil return problems in industrial refrigeration systems are most
likely caused by:
A. Excessive superheat
B. Low refrigerant velocity in suction piping
C. High condenser pressure
D. High ambient temperature
Answer: B. Low refrigerant velocity in suction piping
Rationale: Oil depends upon refrigerant velocity to return to
compressors. Low load conditions or oversized suction piping may
prevent adequate oil transport.
6. In a shell-and-tube condenser, scaling primarily causes:
A. Lower condensing pressure
B. Improved heat transfer
C. Increased condensing temperature and compressor workload
D. Lower refrigerant temperature
Answer: C. Increased condensing temperature and compressor
workload
Rationale: Scale acts as insulation, reducing heat transfer efficiency.
The refrigerant must condense at higher temperatures and pressures,
increasing compressor energy consumption.
3
, 7. Which safety device prevents compressor damage due to excessive
discharge pressure?
A. Flow switch
B. High-pressure cutout
C. Low ambient control
D. Time-delay relay
Answer: B. High-pressure cutout
Rationale: High-pressure cutout switches immediately stop compressor
operation when discharge pressure exceeds safe operating limits.
8. A star (Y) motor connection primarily reduces:
A. Voltage across each winding during startup
B. Refrigerant flow
C. Oil circulation
D. Condenser capacity
Answer: A. Voltage across each winding during startup
Rationale: Star-delta starters reduce inrush current by lowering voltage
applied to each winding during startup before switching to full-voltage
delta operation.
9. The purpose of compressor crankcase heaters is to:
A. Increase oil viscosity
B. Prevent refrigerant migration into compressor oil
C. Raise discharge pressure
D. Reduce evaporator load
Answer: B. Prevent refrigerant migration into compressor oil
4
EXAM WITH ACTUAL QUESTIONS AND
VERIFIED ANSWERS, PLUS EXPLAINED
RATIONALES/EXPERT VERIFIED FOR
GUARANTEED 100% PASS 2026/LATEST
UPDATE/INSTANT DOWNLOAD PDF
1. In a large industrial chilled water system, the primary purpose of
installing variable frequency drives (VFDs) on centrifugal pump
motors is to:
A. Increase refrigerant pressure
B. Reduce motor speed to match system demand while improving
efficiency
C. Increase pump discharge pressure regardless of load
D. Prevent water hammer by increasing flow
Answer: B. Reduce motor speed to match system demand while
improving efficiency
Rationale: VFDs adjust motor speed according to system demand,
significantly reducing energy consumption because pump power varies
approximately with the cube of speed. Industrial HVAC systems
commonly utilize VFDs to maintain differential pressure while
minimizing electrical costs.
2. A technician measures 480V across a three-phase motor but finds
the motor is not operating. The first electrical measurement should
be:
A. Refrigerant pressure
B. Amp draw with the disconnect open
1
,C. Voltage at each winding and continuity through the overloads
D. Water temperature
Answer: C. Voltage at each winding and continuity through the
overloads
Rationale: Adequate line voltage does not guarantee power reaches the
motor windings. Open overloads, failed contactors, or damaged
windings can interrupt current flow despite correct supply voltage.
3. During compressor analysis, excessively high discharge
temperatures primarily indicate:
A. Floodback
B. Low compression ratio
C. High compression ratio or insufficient suction cooling
D. Excessive oil level
Answer: C. High compression ratio or insufficient suction cooling
Rationale: High compression ratios significantly increase discharge
temperatures. Low suction pressure, dirty condensers, non-
condensables, or inadequate suction gas cooling can all contribute.
4. Which psychrometric process occurs when air passes over a
cooling coil operating below the dew point?
A. Sensible heating
B. Sensible cooling only
C. Sensible cooling and latent cooling
D. Humidification
Answer: C. Sensible cooling and latent cooling
2
,Rationale: When coil temperature falls below the dew point, moisture
condenses from the air while temperature decreases, producing both
sensible and latent heat removal.
5. Oil return problems in industrial refrigeration systems are most
likely caused by:
A. Excessive superheat
B. Low refrigerant velocity in suction piping
C. High condenser pressure
D. High ambient temperature
Answer: B. Low refrigerant velocity in suction piping
Rationale: Oil depends upon refrigerant velocity to return to
compressors. Low load conditions or oversized suction piping may
prevent adequate oil transport.
6. In a shell-and-tube condenser, scaling primarily causes:
A. Lower condensing pressure
B. Improved heat transfer
C. Increased condensing temperature and compressor workload
D. Lower refrigerant temperature
Answer: C. Increased condensing temperature and compressor
workload
Rationale: Scale acts as insulation, reducing heat transfer efficiency.
The refrigerant must condense at higher temperatures and pressures,
increasing compressor energy consumption.
3
, 7. Which safety device prevents compressor damage due to excessive
discharge pressure?
A. Flow switch
B. High-pressure cutout
C. Low ambient control
D. Time-delay relay
Answer: B. High-pressure cutout
Rationale: High-pressure cutout switches immediately stop compressor
operation when discharge pressure exceeds safe operating limits.
8. A star (Y) motor connection primarily reduces:
A. Voltage across each winding during startup
B. Refrigerant flow
C. Oil circulation
D. Condenser capacity
Answer: A. Voltage across each winding during startup
Rationale: Star-delta starters reduce inrush current by lowering voltage
applied to each winding during startup before switching to full-voltage
delta operation.
9. The purpose of compressor crankcase heaters is to:
A. Increase oil viscosity
B. Prevent refrigerant migration into compressor oil
C. Raise discharge pressure
D. Reduce evaporator load
Answer: B. Prevent refrigerant migration into compressor oil
4
