HVAC: EPA 608 CERTIFICATION STUDY GUIDE
QUESTIONS NEWEST 2025 ACTUAL EXAM 100
QUESTIONS AND CORRECT DETAILED ANSWERS /
ALREADY GRADED A+
Terms in this set (100)
Are there drop-in No because the new refrigerants are incompatible with the
replacements for R-12 oils and lubricants used in R-12 systems.
systems? Why or why not?
What type of oil is used inEster based oils and they do not mix with other oils R-
134a and what oils will it mix with?
What type of lubricant is Alkylbenzene lubricant
used with HCFCs?
What is difference b/w Ternary blends are three-part mixtures whereas azeotropic
ternary blend a azeotropic blends are blends of two or more compounds that act like a
blend? single compound.
What is the trait of a It absorbs (takes on) moisture
hygroscopic lubricant?
What is temperature glide Temp. blend is the difference between the dew point and the
and what type of blend bubble point
won't have it?
Dew Point Occurs when saturation temp in evaporator causes refrigerant to
change from liquid to vapor
Bubble Point Occurs when saturation temp in condenser changes refrigerant from
vapor to liquid
, Will the gases in a ternary No because different refrigerants in blend have
blend leak at the same rate? different vapor pressures, causing them to leak at
Why or why not? uneven rates
Refrigeration Process transfer of heat from one place to another
Evaporator 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 Takes low pressure, low temp vapor and changes it to a
high-temp, high-pressure, superheated vapor and delivers
it to the condenser
Condenser Rejects heat from system and changes refrigerant from high-
temp, high-pressure vapor into highpressure, high-temp
liquid
Metering Device reduces pressure of refrigerant and changes the
highpressure, high-temp liquid into low pressure, low temp
liquid.
Compound Gauge Typically blue and measures low pressure (psig) and vacuum
(inHg).
High Pressure Gauge Red and measures high side (discharge) pressure. 0 to
500 psi
What does a compressor Vapor
compress?
Why will refrigerant Because of the vapor pressure difference between refrigerant and
migrate to the crankcase in oil
a compressor?
What color is the high Red
pressure gauge?
What color is the low Blue
pressure gauge?
QUESTIONS NEWEST 2025 ACTUAL EXAM 100
QUESTIONS AND CORRECT DETAILED ANSWERS /
ALREADY GRADED A+
Terms in this set (100)
Are there drop-in No because the new refrigerants are incompatible with the
replacements for R-12 oils and lubricants used in R-12 systems.
systems? Why or why not?
What type of oil is used inEster based oils and they do not mix with other oils R-
134a and what oils will it mix with?
What type of lubricant is Alkylbenzene lubricant
used with HCFCs?
What is difference b/w Ternary blends are three-part mixtures whereas azeotropic
ternary blend a azeotropic blends are blends of two or more compounds that act like a
blend? single compound.
What is the trait of a It absorbs (takes on) moisture
hygroscopic lubricant?
What is temperature glide Temp. blend is the difference between the dew point and the
and what type of blend bubble point
won't have it?
Dew Point Occurs when saturation temp in evaporator causes refrigerant to
change from liquid to vapor
Bubble Point Occurs when saturation temp in condenser changes refrigerant from
vapor to liquid
, Will the gases in a ternary No because different refrigerants in blend have
blend leak at the same rate? different vapor pressures, causing them to leak at
Why or why not? uneven rates
Refrigeration Process transfer of heat from one place to another
Evaporator 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 Takes low pressure, low temp vapor and changes it to a
high-temp, high-pressure, superheated vapor and delivers
it to the condenser
Condenser Rejects heat from system and changes refrigerant from high-
temp, high-pressure vapor into highpressure, high-temp
liquid
Metering Device reduces pressure of refrigerant and changes the
highpressure, high-temp liquid into low pressure, low temp
liquid.
Compound Gauge Typically blue and measures low pressure (psig) and vacuum
(inHg).
High Pressure Gauge Red and measures high side (discharge) pressure. 0 to
500 psi
What does a compressor Vapor
compress?
Why will refrigerant Because of the vapor pressure difference between refrigerant and
migrate to the crankcase in oil
a compressor?
What color is the high Red
pressure gauge?
What color is the low Blue
pressure gauge?
