EPA 608 CERTIFICATION STUDY GUIDE
2026 COMPLETE QUESTIONS AND
SOLUTIONS VERIFIED A+
● What type of oil is used in R-134a and what oils will it mix with?.
Answer: Ester based oils and they do not mix with other oils
● What type of lubricant is used with HCFCs?. Answer: Alkylbenzene
lubricant
● What is difference b/w ternary blend a azeotropic blend?. Answer:
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?. Answer: It absorbs (takes
on) moisture
● What is temperature glide and what type of blend won't have it?.
Answer: Temp. blend is the difference between the dew point and the
bubble point
● Dew Point. Answer: Occurs when saturation temp in evaporator
causes refrigerant to change from liquid to vapor
,● Bubble Point. Answer: Occurs when saturation temp in condenser
changes refrigerant from vapor to liquid
● Will the gases in a ternary blend leak at the same rate? Why or why
not?. Answer: No because different refrigerants in blend have different
vapor pressures, causing them to leak at uneven rates
● Refrigeration Process. Answer: transfer of heat from one place to
another
● Evaporator. Answer: Absorbs heat into system from space to be
cooled. Absorption of heat causes refrigerant to boil. Upon leaving,
refrigerant changed to low pressure, low temperature vapor
● Compressor. Answer: Takes low pressure, low temp vapor and
changes it to a high-temp, high-pressure, superheated vapor and delivers
it to the condenser
● Condenser. Answer: Rejects heat from system and changes refrigerant
from high-temp, high-pressure vapor into high-pressure, high-temp
liquid
● Metering Device. Answer: reduces pressure of refrigerant and changes
the high-pressure, high-temp liquid into low pressure, low temp liquid.
, ● Compound Gauge. Answer: Typically blue and measures low pressure
(psig) and vacuum (inHg).
● High Pressure Gauge. Answer: Red and measures high side
(discharge) pressure. 0 to 500 psi
● What does a compressor compress?. Answer: Vapor
● Why will refrigerant migrate to the crankcase in a compressor?.
Answer: Because of the vapor pressure difference between refrigerant
and oil
● What color is the high pressure gauge?. Answer: Red
● What color is the low pressure gauge?. Answer: Blue
● What needs to happen if oil has been contaminated by burnout?.
Answer: Triple evacuate system, install permanent filter-drier, conduct
deep vacuum before recharging
● What are three Rs of refrigeration?. Answer: Recover, recycle, reclaim
2026 COMPLETE QUESTIONS AND
SOLUTIONS VERIFIED A+
● What type of oil is used in R-134a and what oils will it mix with?.
Answer: Ester based oils and they do not mix with other oils
● What type of lubricant is used with HCFCs?. Answer: Alkylbenzene
lubricant
● What is difference b/w ternary blend a azeotropic blend?. Answer:
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?. Answer: It absorbs (takes
on) moisture
● What is temperature glide and what type of blend won't have it?.
Answer: Temp. blend is the difference between the dew point and the
bubble point
● Dew Point. Answer: Occurs when saturation temp in evaporator
causes refrigerant to change from liquid to vapor
,● Bubble Point. Answer: Occurs when saturation temp in condenser
changes refrigerant from vapor to liquid
● Will the gases in a ternary blend leak at the same rate? Why or why
not?. Answer: No because different refrigerants in blend have different
vapor pressures, causing them to leak at uneven rates
● Refrigeration Process. Answer: transfer of heat from one place to
another
● Evaporator. Answer: Absorbs heat into system from space to be
cooled. Absorption of heat causes refrigerant to boil. Upon leaving,
refrigerant changed to low pressure, low temperature vapor
● Compressor. Answer: Takes low pressure, low temp vapor and
changes it to a high-temp, high-pressure, superheated vapor and delivers
it to the condenser
● Condenser. Answer: Rejects heat from system and changes refrigerant
from high-temp, high-pressure vapor into high-pressure, high-temp
liquid
● Metering Device. Answer: reduces pressure of refrigerant and changes
the high-pressure, high-temp liquid into low pressure, low temp liquid.
, ● Compound Gauge. Answer: Typically blue and measures low pressure
(psig) and vacuum (inHg).
● High Pressure Gauge. Answer: Red and measures high side
(discharge) pressure. 0 to 500 psi
● What does a compressor compress?. Answer: Vapor
● Why will refrigerant migrate to the crankcase in a compressor?.
Answer: Because of the vapor pressure difference between refrigerant
and oil
● What color is the high pressure gauge?. Answer: Red
● What color is the low pressure gauge?. Answer: Blue
● What needs to happen if oil has been contaminated by burnout?.
Answer: Triple evacuate system, install permanent filter-drier, conduct
deep vacuum before recharging
● What are three Rs of refrigeration?. Answer: Recover, recycle, reclaim
