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EPA Section 608 Type III Certification
Questions And Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A Instant Download Pdf
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1. What type of refrigeration equipment is covered by an EPA Section 608 Type
III certification?
A. Small appliances
B. High-pressure appliances
C. Low-pressure appliances
D. Motor vehicle air conditioners
Answer: Low-pressure appliances
Rationale: Type III certification is specifically for technicians who service or
dispose of low-pressure appliances. Common examples include centrifugal
chillers using refrigerants such as R-11 and R-123.
2. Which refrigerant is commonly associated with low-pressure centrifugal
chillers?
A. R-22
B. R-410A
C. R-404A
D. R-123
Answer: R-123
,Rationale: R-123 is a commonly encountered low-pressure refrigerant used in
centrifugal chiller applications. R-11 is another historically common low-
pressure refrigerant.
3. Which refrigerant is also classified as a low-pressure refrigerant?
A. R-134a
B. R-502
C. R-11
D. R-404A
Answer: R-11
Rationale: EPA materials identify R-11 and R-123 as examples of low-pressure
refrigerants.
4. A centrifugal chiller normally operates with the evaporator below
atmospheric pressure. What is the major concern?
A. Excessive compressor discharge pressure
B. Air and moisture can leak into the system
C. Liquid refrigerant will always enter the compressor
D. Condenser pressure will become zero
Answer: Air and moisture can leak into the system
Rationale: Because many low-pressure chillers operate below atmospheric
pressure, leaks can allow air and moisture to enter rather than refrigerant
necessarily escaping.
5. What is the primary purpose of a purge unit on a low-pressure centrifugal
chiller?
A. Add refrigerant to the system
B. Increase compressor capacity
C. Remove noncondensable gases from the system
D. Remove oil from the compressor
,Answer: Remove noncondensable gases from the system
Rationale: A purge unit removes air and other noncondensable gases that can
enter a low-pressure system and impair condenser performance.
6. What can excessive air in a low-pressure refrigeration system cause?
A. Lower condensing pressure only
B. Increased head pressure and reduced efficiency
C. Increased refrigerant purity
D. Elimination of purge operation
Answer: Increased head pressure and reduced efficiency
Rationale: Noncondensables occupy condenser space and interfere with heat
transfer, causing higher condensing pressure and reduced system efficiency.
7. What is one indication that air may have entered a low-pressure chiller?
A. Low oil temperature
B. Excessive purge-unit operation
C. Increased evaporator vacuum only
D. Reduced water flow only
Answer: Excessive purge-unit operation
Rationale: EPA identifies excessive purging as a sign that leakage of air or other
noncondensables into a low-pressure system may be occurring.
8. Why should water be circulated through a chiller during refrigerant
evacuation?
A. To increase refrigerant pressure
B. To heat the compressor
C. To prevent water in the tubes from freezing
D. To increase condenser pressure
Answer: To prevent water in the tubes from freezing
, Rationale: As refrigerant is removed, evaporator pressure and temperature can
fall. Circulating or removing water helps prevent freezing during evacuation.
9. What can happen if water freezes inside a chiller's evaporator tubes?
A. Refrigerant becomes more pure
B. Tubes can be damaged or ruptured
C. Compressor efficiency increases
D. Purge operation stops permanently
Answer: Tubes can be damaged or ruptured
Rationale: Water expands when it freezes, creating significant mechanical stress
that can damage heat-exchanger tubes.
10. During recovery from a low-pressure chiller, which refrigerant should
generally be recovered first?
A. Vapor only
B. Oil vapor
C. Liquid refrigerant
D. Nitrogen
Answer: Liquid refrigerant
Rationale: Recovering liquid refrigerant at the beginning of the recovery process
can substantially speed recovery because liquid contains much more refrigerant
mass per unit volume than vapor.
11. After recovering liquid refrigerant from a low-pressure system, what must
generally be recovered?
A. Only nitrogen
B. Only oil
C. The remaining refrigerant vapor
D. Condenser water
Answer: The remaining refrigerant vapor
EPA Section 608 Type III Certification
Questions And Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A Instant Download Pdf
___________________________________________________________________
1. What type of refrigeration equipment is covered by an EPA Section 608 Type
III certification?
A. Small appliances
B. High-pressure appliances
C. Low-pressure appliances
D. Motor vehicle air conditioners
Answer: Low-pressure appliances
Rationale: Type III certification is specifically for technicians who service or
dispose of low-pressure appliances. Common examples include centrifugal
chillers using refrigerants such as R-11 and R-123.
2. Which refrigerant is commonly associated with low-pressure centrifugal
chillers?
A. R-22
B. R-410A
C. R-404A
D. R-123
Answer: R-123
,Rationale: R-123 is a commonly encountered low-pressure refrigerant used in
centrifugal chiller applications. R-11 is another historically common low-
pressure refrigerant.
3. Which refrigerant is also classified as a low-pressure refrigerant?
A. R-134a
B. R-502
C. R-11
D. R-404A
Answer: R-11
Rationale: EPA materials identify R-11 and R-123 as examples of low-pressure
refrigerants.
4. A centrifugal chiller normally operates with the evaporator below
atmospheric pressure. What is the major concern?
A. Excessive compressor discharge pressure
B. Air and moisture can leak into the system
C. Liquid refrigerant will always enter the compressor
D. Condenser pressure will become zero
Answer: Air and moisture can leak into the system
Rationale: Because many low-pressure chillers operate below atmospheric
pressure, leaks can allow air and moisture to enter rather than refrigerant
necessarily escaping.
5. What is the primary purpose of a purge unit on a low-pressure centrifugal
chiller?
A. Add refrigerant to the system
B. Increase compressor capacity
C. Remove noncondensable gases from the system
D. Remove oil from the compressor
,Answer: Remove noncondensable gases from the system
Rationale: A purge unit removes air and other noncondensable gases that can
enter a low-pressure system and impair condenser performance.
6. What can excessive air in a low-pressure refrigeration system cause?
A. Lower condensing pressure only
B. Increased head pressure and reduced efficiency
C. Increased refrigerant purity
D. Elimination of purge operation
Answer: Increased head pressure and reduced efficiency
Rationale: Noncondensables occupy condenser space and interfere with heat
transfer, causing higher condensing pressure and reduced system efficiency.
7. What is one indication that air may have entered a low-pressure chiller?
A. Low oil temperature
B. Excessive purge-unit operation
C. Increased evaporator vacuum only
D. Reduced water flow only
Answer: Excessive purge-unit operation
Rationale: EPA identifies excessive purging as a sign that leakage of air or other
noncondensables into a low-pressure system may be occurring.
8. Why should water be circulated through a chiller during refrigerant
evacuation?
A. To increase refrigerant pressure
B. To heat the compressor
C. To prevent water in the tubes from freezing
D. To increase condenser pressure
Answer: To prevent water in the tubes from freezing
, Rationale: As refrigerant is removed, evaporator pressure and temperature can
fall. Circulating or removing water helps prevent freezing during evacuation.
9. What can happen if water freezes inside a chiller's evaporator tubes?
A. Refrigerant becomes more pure
B. Tubes can be damaged or ruptured
C. Compressor efficiency increases
D. Purge operation stops permanently
Answer: Tubes can be damaged or ruptured
Rationale: Water expands when it freezes, creating significant mechanical stress
that can damage heat-exchanger tubes.
10. During recovery from a low-pressure chiller, which refrigerant should
generally be recovered first?
A. Vapor only
B. Oil vapor
C. Liquid refrigerant
D. Nitrogen
Answer: Liquid refrigerant
Rationale: Recovering liquid refrigerant at the beginning of the recovery process
can substantially speed recovery because liquid contains much more refrigerant
mass per unit volume than vapor.
11. After recovering liquid refrigerant from a low-pressure system, what must
generally be recovered?
A. Only nitrogen
B. Only oil
C. The remaining refrigerant vapor
D. Condenser water
Answer: The remaining refrigerant vapor
