Fall Semester 2026–2027 EPA 608 HVAC
Certification Updated 2026 | 190+ Questions
and Answers | EPA Section 608 HVAC
Certification Study Guide, Practice Exam,
Comprehensive Review, Exam Prep Test Bank,
Core Certification, Type I, Type II, Type III,
Universal Certification, Refrigerant Recovery,
Recycling and Safety, Environmental
Regulations, HVAC Systems, Detailed
Rationales and Complete Revision Material
Question 1: According to EPA regulations, what is the maximum allowable
annual leak rate for a commercial refrigeration system containing 50 pounds or
more of refrigerant before mandatory repair requirements are triggered?
A. 15%
B. 20%
C. 35%
D. 50%
CORRECT ANSWER: C. 35%
Rationale: Under Section 608 of the Clean Air Act, commercial and industrial process
refrigeration appliances with a full charge of 50 pounds or more of refrigerant must be
repaired when the leak rate exceeds 35% per year. Comfort cooling appliances have a
lower threshold of 15%, making option C the correct choice for commercial refrigeration
systems .
Question 2: A technician is working on a low-pressure chiller and notices the
purge unit is running excessively. What does this condition most likely
indicate?
A. The system is overcharged with refrigerant
B. There is a refrigerant leak allowing air and moisture to enter
C. The compressor is failing
D. The expansion valve is stuck open
CORRECT ANSWER: B. There is a refrigerant leak allowing air and moisture to
enter
Rationale: Excessive running of a purge unit on a low-pressure chiller typically indicates
that air and moisture are entering the system through a leak. Since low-pressure systems
operate below atmospheric pressure, leaks allow air and moisture to be drawn in,
causing the purge unit to run frequently to remove non-condensables and moisture. This
is one of the visible warning signs of a leak in a low-pressure system .
,Question 3: What is the minimum evacuation level required for a low-pressure
appliance manufactured after November 15, 1993, before it can be opened for
service?
A. 25 inches of mercury vacuum
B. 15 inches of mercury vacuum
C. 25 mm of mercury absolute pressure
D. 10 inches of mercury vacuum
CORRECT ANSWER: C. 25 mm of mercury absolute pressure
Rationale: EPA regulations require that low-pressure appliances manufactured after
November 15, 1993, be evacuated to 25 mm of mercury absolute pressure before they
can be opened for major service. For appliances manufactured before this date, the
requirement was 25 inches of mercury vacuum .
Question 4: When pressurizing a low-pressure system for leak checking, what
is the maximum safe pressure that should be applied to avoid rupturing the
rupture disc?
A. 5 psig
B. 10 psig
C. 15 psig
D. 20 psig
CORRECT ANSWER: B. 10 psig
Rationale: When leak checking a low-pressure system, technicians must be careful not
to exceed 10 psig when pressurizing the system. Exceeding this pressure can cause the
rupture disc to fail, which is typically set for 15 psig on the system itself. The recovery
unit's high-pressure cut-out is generally set for 10 psig to prevent damage to the low-
pressure system .
Question 5: What is the correct procedure for leak testing a water box on a
low-pressure chiller?
A. Pressurize the water box with nitrogen to 100 psig
B. Remove the water and place the leak detector probe through the drain valve
C. Add water to the box and check for bubbles
D. Pressurize the water box with refrigerant and use an electronic leak detector
CORRECT ANSWER: B. Remove the water and place the leak detector probe
through the drain valve
Rationale: To properly leak test a water box on a low-pressure chiller, technicians should
ensure the water has been removed, then place the leak detector probe through the
drain valve. This allows the detector to sample the air inside the water box for any
refrigerant that may have leaked from the tubes .
,Question 6: Which of the following refrigerants would be classified as a high-
pressure refrigerant requiring Type II certification for servicing?
A. R-123
B. R-134a
C. R-11
D. R-113
CORRECT ANSWER: B. R-134a
Rationale: Type II certification is required for servicing high-pressure or very high-
pressure appliances, except small appliances and MVACs. R-134a is a high-pressure
refrigerant commonly used in medium-temperature refrigeration and automotive
applications. In contrast, R-11, R-113, and R-123 are low-pressure refrigerants requiring
Type III certification .
Question 7: What action should a technician take if a refrigeration system fails
to reach the required evacuation level due to a leak?
A. Evacuate the system to the lowest attainable level before performing a major repair
B. Continue evacuating until the required level is reached regardless of time
C. Recharge the system with nitrogen and then evacuate again
D. Perform the repair without further evacuation
CORRECT ANSWER: A. Evacuate the system to the lowest attainable level
before performing a major repair
Rationale: If a leak prevents the system from reaching the required vacuum level, EPA
regulations allow the system to be evacuated to the lowest attainable level before a
major repair. The leak must be repaired before the system is recharged, and proper
evacuation must be completed after the repair .
Question 8: When recovering refrigerant from a system with a condenser
located below the receiver, where should the technician remove the
refrigerant?
A. From the compressor suction line
B. From the condenser outlet
C. From the receiver outlet
D. From the evaporator inlet
CORRECT ANSWER: B. From the condenser outlet
Rationale: In a system where the condenser is located below the receiver, the technician
should remove refrigerant from the condenser outlet. This position allows for the most
effective liquid recovery because the refrigerant will naturally flow to the lowest point,
and the condenser outlet provides optimal access for liquid refrigerant removal .
Question 9: Why should a technician never charge a system that is in a deep
vacuum with liquid refrigerant?
, A. It could cause the compressor to overheat
B. The refrigerant will not flow into the system
C. The refrigerant could freeze moisture in the tubes and cause damage
D. It will cause the system pressure to rise too quickly
CORRECT ANSWER: C. The refrigerant could freeze moisture in the tubes and
cause damage
Rationale: Charging liquid refrigerant into a system in a deep vacuum can cause the
refrigerant to boil rapidly, lowering the temperature enough to freeze any moisture
present in the tubes. This can lead to ice blockages and potential damage to the system.
The rapid boiling also creates a risk of slugging the compressor .
Question 10: What is the primary purpose of installing a filter-drier in a
refrigeration system after a compressor burnout?
A. To increase system cooling capacity
B. To remove moisture and contaminants from the system
C. To reduce energy consumption
D. To prevent the system from over-pressurizing
CORRECT ANSWER: B. To remove moisture and contaminants from the system
Rationale: A filter-drier is installed in a refrigeration system to remove moisture, acid,
and other contaminants that can cause damage to the system components. Following a
compressor burnout, it is especially important to install a filter-drier to clean the system
before recharging .
Question 11: A technician is preparing to recover refrigerant from a small
appliance. The appliance is manufactured, charged, and hermetically sealed at
the factory and contains 5 pounds of refrigerant. What is the classification of
this appliance?
A. Type I appliance
B. Type II appliance
C. Type III appliance
D. MVAC appliance
CORRECT ANSWER: A. Type I appliance
Rationale: The EPA defines a small appliance as one that is manufactured, charged, and
hermetically sealed in the factory, and contains five pounds or less of refrigerant. These
appliances require Type I certification for servicing. The 5-pound threshold is the key
criteria; the appliance is not classified by refrigerant type but by the charge amount and
factory-sealed construction .
Question 12: When a technician is handling a cylinder containing mixed
refrigerants, what should they expect from a reclamation center?
Certification Updated 2026 | 190+ Questions
and Answers | EPA Section 608 HVAC
Certification Study Guide, Practice Exam,
Comprehensive Review, Exam Prep Test Bank,
Core Certification, Type I, Type II, Type III,
Universal Certification, Refrigerant Recovery,
Recycling and Safety, Environmental
Regulations, HVAC Systems, Detailed
Rationales and Complete Revision Material
Question 1: According to EPA regulations, what is the maximum allowable
annual leak rate for a commercial refrigeration system containing 50 pounds or
more of refrigerant before mandatory repair requirements are triggered?
A. 15%
B. 20%
C. 35%
D. 50%
CORRECT ANSWER: C. 35%
Rationale: Under Section 608 of the Clean Air Act, commercial and industrial process
refrigeration appliances with a full charge of 50 pounds or more of refrigerant must be
repaired when the leak rate exceeds 35% per year. Comfort cooling appliances have a
lower threshold of 15%, making option C the correct choice for commercial refrigeration
systems .
Question 2: A technician is working on a low-pressure chiller and notices the
purge unit is running excessively. What does this condition most likely
indicate?
A. The system is overcharged with refrigerant
B. There is a refrigerant leak allowing air and moisture to enter
C. The compressor is failing
D. The expansion valve is stuck open
CORRECT ANSWER: B. There is a refrigerant leak allowing air and moisture to
enter
Rationale: Excessive running of a purge unit on a low-pressure chiller typically indicates
that air and moisture are entering the system through a leak. Since low-pressure systems
operate below atmospheric pressure, leaks allow air and moisture to be drawn in,
causing the purge unit to run frequently to remove non-condensables and moisture. This
is one of the visible warning signs of a leak in a low-pressure system .
,Question 3: What is the minimum evacuation level required for a low-pressure
appliance manufactured after November 15, 1993, before it can be opened for
service?
A. 25 inches of mercury vacuum
B. 15 inches of mercury vacuum
C. 25 mm of mercury absolute pressure
D. 10 inches of mercury vacuum
CORRECT ANSWER: C. 25 mm of mercury absolute pressure
Rationale: EPA regulations require that low-pressure appliances manufactured after
November 15, 1993, be evacuated to 25 mm of mercury absolute pressure before they
can be opened for major service. For appliances manufactured before this date, the
requirement was 25 inches of mercury vacuum .
Question 4: When pressurizing a low-pressure system for leak checking, what
is the maximum safe pressure that should be applied to avoid rupturing the
rupture disc?
A. 5 psig
B. 10 psig
C. 15 psig
D. 20 psig
CORRECT ANSWER: B. 10 psig
Rationale: When leak checking a low-pressure system, technicians must be careful not
to exceed 10 psig when pressurizing the system. Exceeding this pressure can cause the
rupture disc to fail, which is typically set for 15 psig on the system itself. The recovery
unit's high-pressure cut-out is generally set for 10 psig to prevent damage to the low-
pressure system .
Question 5: What is the correct procedure for leak testing a water box on a
low-pressure chiller?
A. Pressurize the water box with nitrogen to 100 psig
B. Remove the water and place the leak detector probe through the drain valve
C. Add water to the box and check for bubbles
D. Pressurize the water box with refrigerant and use an electronic leak detector
CORRECT ANSWER: B. Remove the water and place the leak detector probe
through the drain valve
Rationale: To properly leak test a water box on a low-pressure chiller, technicians should
ensure the water has been removed, then place the leak detector probe through the
drain valve. This allows the detector to sample the air inside the water box for any
refrigerant that may have leaked from the tubes .
,Question 6: Which of the following refrigerants would be classified as a high-
pressure refrigerant requiring Type II certification for servicing?
A. R-123
B. R-134a
C. R-11
D. R-113
CORRECT ANSWER: B. R-134a
Rationale: Type II certification is required for servicing high-pressure or very high-
pressure appliances, except small appliances and MVACs. R-134a is a high-pressure
refrigerant commonly used in medium-temperature refrigeration and automotive
applications. In contrast, R-11, R-113, and R-123 are low-pressure refrigerants requiring
Type III certification .
Question 7: What action should a technician take if a refrigeration system fails
to reach the required evacuation level due to a leak?
A. Evacuate the system to the lowest attainable level before performing a major repair
B. Continue evacuating until the required level is reached regardless of time
C. Recharge the system with nitrogen and then evacuate again
D. Perform the repair without further evacuation
CORRECT ANSWER: A. Evacuate the system to the lowest attainable level
before performing a major repair
Rationale: If a leak prevents the system from reaching the required vacuum level, EPA
regulations allow the system to be evacuated to the lowest attainable level before a
major repair. The leak must be repaired before the system is recharged, and proper
evacuation must be completed after the repair .
Question 8: When recovering refrigerant from a system with a condenser
located below the receiver, where should the technician remove the
refrigerant?
A. From the compressor suction line
B. From the condenser outlet
C. From the receiver outlet
D. From the evaporator inlet
CORRECT ANSWER: B. From the condenser outlet
Rationale: In a system where the condenser is located below the receiver, the technician
should remove refrigerant from the condenser outlet. This position allows for the most
effective liquid recovery because the refrigerant will naturally flow to the lowest point,
and the condenser outlet provides optimal access for liquid refrigerant removal .
Question 9: Why should a technician never charge a system that is in a deep
vacuum with liquid refrigerant?
, A. It could cause the compressor to overheat
B. The refrigerant will not flow into the system
C. The refrigerant could freeze moisture in the tubes and cause damage
D. It will cause the system pressure to rise too quickly
CORRECT ANSWER: C. The refrigerant could freeze moisture in the tubes and
cause damage
Rationale: Charging liquid refrigerant into a system in a deep vacuum can cause the
refrigerant to boil rapidly, lowering the temperature enough to freeze any moisture
present in the tubes. This can lead to ice blockages and potential damage to the system.
The rapid boiling also creates a risk of slugging the compressor .
Question 10: What is the primary purpose of installing a filter-drier in a
refrigeration system after a compressor burnout?
A. To increase system cooling capacity
B. To remove moisture and contaminants from the system
C. To reduce energy consumption
D. To prevent the system from over-pressurizing
CORRECT ANSWER: B. To remove moisture and contaminants from the system
Rationale: A filter-drier is installed in a refrigeration system to remove moisture, acid,
and other contaminants that can cause damage to the system components. Following a
compressor burnout, it is especially important to install a filter-drier to clean the system
before recharging .
Question 11: A technician is preparing to recover refrigerant from a small
appliance. The appliance is manufactured, charged, and hermetically sealed at
the factory and contains 5 pounds of refrigerant. What is the classification of
this appliance?
A. Type I appliance
B. Type II appliance
C. Type III appliance
D. MVAC appliance
CORRECT ANSWER: A. Type I appliance
Rationale: The EPA defines a small appliance as one that is manufactured, charged, and
hermetically sealed in the factory, and contains five pounds or less of refrigerant. These
appliances require Type I certification for servicing. The 5-pound threshold is the key
criteria; the appliance is not classified by refrigerant type but by the charge amount and
factory-sealed construction .
Question 12: When a technician is handling a cylinder containing mixed
refrigerants, what should they expect from a reclamation center?
