EPA 608 PREPARATION TEST 2026
QUESTIONS AND CORRECT ANSWERS
GRADED 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
QUESTIONS AND CORRECT ANSWERS
GRADED 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
