AL REF Refrigeration Contractor Exam
Questions and Correct Answers (Verified
Answers) Plus Rationale 2027 Q&A|
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1. In refrigeration, what is the primary purpose of the evaporator?
a. To reject heat to the surrounding air
b. To compress refrigerant vapor
c. To absorb heat from the refrigerated space
d. To store liquid refrigerant
Answer: c. To absorb heat from the refrigerated space
Rationale: The evaporator is the component where refrigerant
absorbs heat from the refrigerated space or product. As the
refrigerant evaporates, it changes from a low-pressure liquid or liquid-
vapor mixture into vapor. This heat absorption produces the cooling
effect.
, 2. What is the primary function of the compressor in a vapor-
compression refrigeration system?
a. Reduce refrigerant pressure
b. Increase refrigerant vapor pressure and circulate refrigerant
c. Remove moisture from the refrigerant
d. Convert liquid refrigerant directly into ice
Answer: b. Increase refrigerant vapor pressure and circulate
refrigerant
Rationale: The compressor takes low-pressure refrigerant vapor from
the evaporator and compresses it into a high-pressure, high-
temperature vapor. It also provides the pressure difference necessary
to move refrigerant through the system.
3. Which component rejects heat from the refrigerant to the
surroundings?
a. Evaporator
b. Expansion valve
c. Condenser
d. Accumulator
Answer: c. Condenser
,Rationale: The condenser receives high-pressure, high-temperature
refrigerant vapor from the compressor. Heat is transferred from the
refrigerant to the surrounding air or water, causing the refrigerant to
condense into a liquid.
4. What is the main purpose of a thermostatic expansion valve
(TXV)?
a. Increase compressor discharge pressure
b. Control refrigerant flow into the evaporator
c. Remove oil from the compressor
d. Increase condenser airflow
Answer: b. Control refrigerant flow into the evaporator
Rationale: A TXV meters refrigerant entering the evaporator while
responding primarily to evaporator outlet superheat. Proper
operation helps maintain adequate evaporator utilization while
preventing excessive liquid refrigerant from returning to the
compressor.
5. Refrigeration is generally defined by Alabama's licensing
framework as equipment used to control temperature or
humidity for a specific space other than human comfort. Which
application best fits this definition?
, a. Residential central air conditioning
b. Office ventilation
c. Walk-in cooler
d. Residential heating furnace
Answer: c. Walk-in cooler
Rationale: Alabama distinguishes commercial refrigeration from
comfort-conditioning applications. Walk-in coolers, commercial
refrigerators, and refrigerated storage systems are examples of
commercial refrigeration equipment covered by the refrigeration
contractor classification.
6. What condition generally exists at the outlet of a properly
operating evaporator in a conventional vapor-compression
system?
a. Superheated vapor
b. Subcooled liquid
c. High-pressure liquid
d. Saturated liquid only
Answer: a. Superheated vapor
Rationale: Refrigerant normally leaves the evaporator as vapor with
some superheat. Superheat indicates that the vapor temperature is
Questions and Correct Answers (Verified
Answers) Plus Rationale 2027 Q&A|
Instant Download Pdf
1. In refrigeration, what is the primary purpose of the evaporator?
a. To reject heat to the surrounding air
b. To compress refrigerant vapor
c. To absorb heat from the refrigerated space
d. To store liquid refrigerant
Answer: c. To absorb heat from the refrigerated space
Rationale: The evaporator is the component where refrigerant
absorbs heat from the refrigerated space or product. As the
refrigerant evaporates, it changes from a low-pressure liquid or liquid-
vapor mixture into vapor. This heat absorption produces the cooling
effect.
, 2. What is the primary function of the compressor in a vapor-
compression refrigeration system?
a. Reduce refrigerant pressure
b. Increase refrigerant vapor pressure and circulate refrigerant
c. Remove moisture from the refrigerant
d. Convert liquid refrigerant directly into ice
Answer: b. Increase refrigerant vapor pressure and circulate
refrigerant
Rationale: The compressor takes low-pressure refrigerant vapor from
the evaporator and compresses it into a high-pressure, high-
temperature vapor. It also provides the pressure difference necessary
to move refrigerant through the system.
3. Which component rejects heat from the refrigerant to the
surroundings?
a. Evaporator
b. Expansion valve
c. Condenser
d. Accumulator
Answer: c. Condenser
,Rationale: The condenser receives high-pressure, high-temperature
refrigerant vapor from the compressor. Heat is transferred from the
refrigerant to the surrounding air or water, causing the refrigerant to
condense into a liquid.
4. What is the main purpose of a thermostatic expansion valve
(TXV)?
a. Increase compressor discharge pressure
b. Control refrigerant flow into the evaporator
c. Remove oil from the compressor
d. Increase condenser airflow
Answer: b. Control refrigerant flow into the evaporator
Rationale: A TXV meters refrigerant entering the evaporator while
responding primarily to evaporator outlet superheat. Proper
operation helps maintain adequate evaporator utilization while
preventing excessive liquid refrigerant from returning to the
compressor.
5. Refrigeration is generally defined by Alabama's licensing
framework as equipment used to control temperature or
humidity for a specific space other than human comfort. Which
application best fits this definition?
, a. Residential central air conditioning
b. Office ventilation
c. Walk-in cooler
d. Residential heating furnace
Answer: c. Walk-in cooler
Rationale: Alabama distinguishes commercial refrigeration from
comfort-conditioning applications. Walk-in coolers, commercial
refrigerators, and refrigerated storage systems are examples of
commercial refrigeration equipment covered by the refrigeration
contractor classification.
6. What condition generally exists at the outlet of a properly
operating evaporator in a conventional vapor-compression
system?
a. Superheated vapor
b. Subcooled liquid
c. High-pressure liquid
d. Saturated liquid only
Answer: a. Superheated vapor
Rationale: Refrigerant normally leaves the evaporator as vapor with
some superheat. Superheat indicates that the vapor temperature is
