1|Pag e
HVAC EPA 608 CERTIFICATION EXAM|| EPA 608
HVAC CERTIFICATION TEST WITH ALL
QUESTIONS AND 100% CORRECT ANSWERS
ALREADY GRADED A+|| LATEST AND
COMPLETE UPDATE 2026-2027 WITH EXPERT
VERIFIED SOLUTIONS|| ASSURED PASS!!!
Are there drop-in replacements for R-12 systems? Why or why not? ✔ No because
the new refrigerants are incompatible with the oils and lubricants used in R-12
systems.
What type of oil is used in R-134a and what oils will it mix with? ✔ Ester based
oils and they do not mix with other oils
What type of lubricant is used with HCFCs? ✔ Alkylbenzene lubricant
What is difference b/w ternary blend a azeotropic blend? ✔ Ternary blends are
three-part mixtures whereas azeotropic blends are blends of two or more
compounds that act like a single compound.
What is the trait of a hygroscopic lubricant? ✔ It absorbs (takes on) moisture
,2|Pag e
What is temperature glide and what type of blend won't have it? ✔ Temp. blend is
the difference between the dew point and the bubble point
Under what circumstances can recovered refrigerant be used? ✔ It may be
returned to the appliance from which it was removed or to another appliance
owned by the same person without being recycled or reclaimed, unless the
appliance is an MVAC or MVAC-like appliance
Where should you remove the refrigerant in a system that has a condenser below
the receiver? ✔ Condenser outlet
How must you recover refrigerant from a parallel system? Why? ✔ Isolate a
parallel compressor system in order to recover refrigerant. Failure to isolate a
parallel compressor system will cause an open equalization that will prevent
refrigerant recovery
Where do leaks commonly occur in low pressure systems? What about open-drive
type compressor systems? ✔ Leaks in gaskets or fittings. The SHAFT SEAL in
open-drive compressor low pressure refrigeration systems is particularly
susceptible to leaks
Does refrigerant go out of the system in low pressure or does air and moisture go
in? Why? ✔ A low-pressure system operates in a vacuum (below atmospheric
pressure) to enter the refrigeration system.
, 3|Pag e
When should a low pressure system be leaked checked according to ASHRAE
guideline 3-1996? ✔ If the pressure in system rises from 1 mm Hg to a level above
2.5 mm Hg during vacuum testing
What does a purge unit do and what is a high efficiency purge unit? ✔ The purge
unit prevents the accumulation of non-condensable substances (air and moisture)
in order to keep the system clean and maintain efficiency: The purge unit removes
air and moisture to prevent reduced condenser surface area, increased head
pressure, compressor surge, increased pressure differential, and system corrosion.
A high efficiency purge system will expel very little refrigerant along with the air.
How does a centrifugal purge unit work? ✔ A centrifugal purge unit takes its
suction from the top of the condenser, removes the air from the system, and
returns the refrigerant to the evaporator.
What are three visible ways to check for leaks in a low pressure system?
✔ Excessive running of a purge system, continuous excessive moisture in the
purge unit could indicate a leak in the condenser or the chiller barrel, high lead
pressure.
What needs to be done to leak check a low pressure system? ✔ Increase the
pressure in the system by use of controlled hot water or heater blankets.
HVAC EPA 608 CERTIFICATION EXAM|| EPA 608
HVAC CERTIFICATION TEST WITH ALL
QUESTIONS AND 100% CORRECT ANSWERS
ALREADY GRADED A+|| LATEST AND
COMPLETE UPDATE 2026-2027 WITH EXPERT
VERIFIED SOLUTIONS|| ASSURED PASS!!!
Are there drop-in replacements for R-12 systems? Why or why not? ✔ No because
the new refrigerants are incompatible with the oils and lubricants used in R-12
systems.
What type of oil is used in R-134a and what oils will it mix with? ✔ Ester based
oils and they do not mix with other oils
What type of lubricant is used with HCFCs? ✔ Alkylbenzene lubricant
What is difference b/w ternary blend a azeotropic blend? ✔ Ternary blends are
three-part mixtures whereas azeotropic blends are blends of two or more
compounds that act like a single compound.
What is the trait of a hygroscopic lubricant? ✔ It absorbs (takes on) moisture
,2|Pag e
What is temperature glide and what type of blend won't have it? ✔ Temp. blend is
the difference between the dew point and the bubble point
Under what circumstances can recovered refrigerant be used? ✔ It may be
returned to the appliance from which it was removed or to another appliance
owned by the same person without being recycled or reclaimed, unless the
appliance is an MVAC or MVAC-like appliance
Where should you remove the refrigerant in a system that has a condenser below
the receiver? ✔ Condenser outlet
How must you recover refrigerant from a parallel system? Why? ✔ Isolate a
parallel compressor system in order to recover refrigerant. Failure to isolate a
parallel compressor system will cause an open equalization that will prevent
refrigerant recovery
Where do leaks commonly occur in low pressure systems? What about open-drive
type compressor systems? ✔ Leaks in gaskets or fittings. The SHAFT SEAL in
open-drive compressor low pressure refrigeration systems is particularly
susceptible to leaks
Does refrigerant go out of the system in low pressure or does air and moisture go
in? Why? ✔ A low-pressure system operates in a vacuum (below atmospheric
pressure) to enter the refrigeration system.
, 3|Pag e
When should a low pressure system be leaked checked according to ASHRAE
guideline 3-1996? ✔ If the pressure in system rises from 1 mm Hg to a level above
2.5 mm Hg during vacuum testing
What does a purge unit do and what is a high efficiency purge unit? ✔ The purge
unit prevents the accumulation of non-condensable substances (air and moisture)
in order to keep the system clean and maintain efficiency: The purge unit removes
air and moisture to prevent reduced condenser surface area, increased head
pressure, compressor surge, increased pressure differential, and system corrosion.
A high efficiency purge system will expel very little refrigerant along with the air.
How does a centrifugal purge unit work? ✔ A centrifugal purge unit takes its
suction from the top of the condenser, removes the air from the system, and
returns the refrigerant to the evaporator.
What are three visible ways to check for leaks in a low pressure system?
✔ Excessive running of a purge system, continuous excessive moisture in the
purge unit could indicate a leak in the condenser or the chiller barrel, high lead
pressure.
What needs to be done to leak check a low pressure system? ✔ Increase the
pressure in the system by use of controlled hot water or heater blankets.
