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EPA 608 CERTIFICATION EXAM 2025
QUESTIONS AND ANSWERS
Mixture - correct answer - A blend of two or more components that do not a
have fixed proportion to one another and that no matter how well blended, they
still retain a separate existence ( oil and water, for example).
Motor Vehicle Air Conditioner (MVAC) - correct answer - Mechanical vapor
compression refrigeration equipment used to cool the driver or passenger
compartment of any motor vehicle. This definition is NOT intended to
encompass the hermetically sealed refrigeration system used on motor vehicles
for refrigerated cargo or the air conditioning systems on passenger buses.
Non-Azeotropic Refrigerant - correct answer - a synonym for zeotropic, which
is the preferred term though less commonly used as a descriptor. Zeotropic
refers to blends comprising multiple components of different volatilities that,
when used in refrigeration cycles, change volumetric composition and
saturation temperatures (exhibit temperature glide) as they evaporate (boil) or
condense at constant pressure. These refrigerants are given a 400-series
ASHRAE designation.
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Non-condensables - correct answer - Gases that will not condense anywhere
in the vapor compression system and typically accumulate in the condenser.
Normal Charge - correct answer - The quantity of refrigerant within the
appliance or appliance component when the appliance is operating with a full
charge of refrigerant.
Opening an Appliance - correct answer - Any service, maintenance, or repair
on an appliance that could be reasonably expected to release refrigerant from
the appliance to the atmosphere unless the refrigerant was previously
recovered from the appliance.
Orifice Plate - correct answer - A passive throttling device, comprised of a
small opening, located upstream of the evaporator, that drops the pressure in
the system, causing refrigerant to flash into a two-phase mixture. It does not
actively control the pressure drop to maintain a prescribed superheat at the
exit of the evaporator.
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Person - correct answer - Any individual or legal entity, including an individual
corporation, partnership, association, state, municipality, political subdivision
of a state, Indian tribe, and any agency, department, or instrumentality of the
United States and any officer, agent, or employee thereof.
Process Stub - correct answer - A length of tubing that provides access to the
refrigerant inside a small appliance or room air conditioner that can be
resealed at the conclusion of repair or service.
PSIA - correct answer - The absolute pressure in pounds per square inch,
where 0 PSIA corresponds to 29.9 inches of mercury vacuum, and 14.7 PSIA
corresponds to 0
PSIG (pounds per square inch gauge). - correct answer - The gauge pressure
in pounds per square inch, where 0 PSIG corresponds to atmospheric pressure
(14.7 PSIA). A positive PSIG value indicates the pressure in pounds per square
inch above the ambient pressure.
Reclamation - correct answer - To reprocess refrigerant to new product
specifications or at least to the purity specified in the ARI
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Standard 700, Specifications for Fluorocarbon Refrigerants, and to verify this
purity using the analytical test procedures described in the standard.
Recovery - correct answer - To remove refrigerant in any condition from an
appliance and to store it in an external container without necessarily testing or
processing it in any way.
Recovery Efficiency - correct answer - The percentage of refrigerant in an
appliance that is recovered by recycling or recovery equipment.
Recovery Vacuum - correct answer - Used to recover refrigerant in the system
and prevent its escape into the atmosphere. This evacuation, which uses an
EPA-approved recovery or recycling machine, is performed on a charged
refrigeration system before the system is opened for repair. Like any other
vacuum, it is never used to determine if the system has any leaks. Before a
Recovery Evacuation is to be performed, the required evacuation level must be
determined based on the quantity and type of charge, and the manufacture
date of the recovery equipment. If the system has a leak, you only need to
recover to atmospheric pressure to avoid ingesting air into the recovered
refrigerant.
EPA 608 CERTIFICATION EXAM 2025
QUESTIONS AND ANSWERS
Mixture - correct answer - A blend of two or more components that do not a
have fixed proportion to one another and that no matter how well blended, they
still retain a separate existence ( oil and water, for example).
Motor Vehicle Air Conditioner (MVAC) - correct answer - Mechanical vapor
compression refrigeration equipment used to cool the driver or passenger
compartment of any motor vehicle. This definition is NOT intended to
encompass the hermetically sealed refrigeration system used on motor vehicles
for refrigerated cargo or the air conditioning systems on passenger buses.
Non-Azeotropic Refrigerant - correct answer - a synonym for zeotropic, which
is the preferred term though less commonly used as a descriptor. Zeotropic
refers to blends comprising multiple components of different volatilities that,
when used in refrigeration cycles, change volumetric composition and
saturation temperatures (exhibit temperature glide) as they evaporate (boil) or
condense at constant pressure. These refrigerants are given a 400-series
ASHRAE designation.
, Page | 2
Non-condensables - correct answer - Gases that will not condense anywhere
in the vapor compression system and typically accumulate in the condenser.
Normal Charge - correct answer - The quantity of refrigerant within the
appliance or appliance component when the appliance is operating with a full
charge of refrigerant.
Opening an Appliance - correct answer - Any service, maintenance, or repair
on an appliance that could be reasonably expected to release refrigerant from
the appliance to the atmosphere unless the refrigerant was previously
recovered from the appliance.
Orifice Plate - correct answer - A passive throttling device, comprised of a
small opening, located upstream of the evaporator, that drops the pressure in
the system, causing refrigerant to flash into a two-phase mixture. It does not
actively control the pressure drop to maintain a prescribed superheat at the
exit of the evaporator.
, Page | 3
Person - correct answer - Any individual or legal entity, including an individual
corporation, partnership, association, state, municipality, political subdivision
of a state, Indian tribe, and any agency, department, or instrumentality of the
United States and any officer, agent, or employee thereof.
Process Stub - correct answer - A length of tubing that provides access to the
refrigerant inside a small appliance or room air conditioner that can be
resealed at the conclusion of repair or service.
PSIA - correct answer - The absolute pressure in pounds per square inch,
where 0 PSIA corresponds to 29.9 inches of mercury vacuum, and 14.7 PSIA
corresponds to 0
PSIG (pounds per square inch gauge). - correct answer - The gauge pressure
in pounds per square inch, where 0 PSIG corresponds to atmospheric pressure
(14.7 PSIA). A positive PSIG value indicates the pressure in pounds per square
inch above the ambient pressure.
Reclamation - correct answer - To reprocess refrigerant to new product
specifications or at least to the purity specified in the ARI
, Page | 4
Standard 700, Specifications for Fluorocarbon Refrigerants, and to verify this
purity using the analytical test procedures described in the standard.
Recovery - correct answer - To remove refrigerant in any condition from an
appliance and to store it in an external container without necessarily testing or
processing it in any way.
Recovery Efficiency - correct answer - The percentage of refrigerant in an
appliance that is recovered by recycling or recovery equipment.
Recovery Vacuum - correct answer - Used to recover refrigerant in the system
and prevent its escape into the atmosphere. This evacuation, which uses an
EPA-approved recovery or recycling machine, is performed on a charged
refrigeration system before the system is opened for repair. Like any other
vacuum, it is never used to determine if the system has any leaks. Before a
Recovery Evacuation is to be performed, the required evacuation level must be
determined based on the quantity and type of charge, and the manufacture
date of the recovery equipment. If the system has a leak, you only need to
recover to atmospheric pressure to avoid ingesting air into the recovered
refrigerant.
