HVAC EPA 608 Certification Study Guide Latest
Update 2024-2025 Actual Exam 100 Questions
and 100% Verified Correct Answers Guaranteed
A+
After removal of liquid, about how much vapor will remain in the system on a 350 ton R-
11 chiller? - CORRECT ANSWER: 100lbs
Are there drop-in replacements for R-12 systems? Why or why not? - CORRECT
ANSWER: No because the new refrigerants are incompatible with the oils and
lubricants used in R-12 systems.
ASHRAE Standard 15-1994 - CORRECT ANSWER: Requires refrigerant sensor that
will sound alarm and automatically start ventilation system in occupied equipment
rooms where refrigerant from leak will concentrate
At what point in the system should you charge a low pressure system and what should
you start the charge with? - CORRECT ANSWER: Charge through the evaporator
charging valve as this is the lowest point on a low pressure system. First charge the
system with vapor until the refrigeration saturation temperature reaches 36 degrees F or
the vapor pressure reaches 16.9" Hg vacuum
Bubble Point - CORRECT ANSWER: Occurs when saturation temp in condenser
changes refrigerant from vapor to liquid
Compound Gauge - CORRECT ANSWER: Typically blue and measures low pressure
(psig) and vacuum (inHg).
Compressor - CORRECT 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 - CORRECT ANSWER: Rejects heat from system and changes refrigerant
from high-temp, high-pressure vapor into high-pressure, high-temp liquid
Describe two ways to speed up recovery - CORRECT ANSWER: Pack the recovery
cylinder in ice and/or apply heat to the appliance. Recover as much as possible in the
liquid phase.
Dew Point - CORRECT ANSWER: Occurs when saturation temp in evaporator causes
refrigerant to change from liquid to vapor
Does refrigerant go out of the system in low pressure or does air and moisture go in?
Why? - CORRECT ANSWER: A low-pressure system operates in a vacuum (below
atmospheric pressure) to enter the refrigeration system.
Evaporator - CORRECT 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
Find pressure for R-22 at 70 degree F. - CORRECT ANSWER: 121.4 psi
Find the pressure for R-12 at 80 degrees F. - CORRECT ANSWER: 84.4 psi
Foaming at start-up may be found in what component? What does this mean? -
CORRECT ANSWER: Refrigerant in the oil will cause oil foaming in the compressor at
start-up
High Pressure Gauge - CORRECT ANSWER: Red and measures high side (discharge)
pressure. 0 to 500 psi
How can you check if a tank contains excess air or non-condensables? - CORRECT
ANSWER: Check pressure inside recovery tank after allowing temp of cylinder to
stabilize to room temperature
Update 2024-2025 Actual Exam 100 Questions
and 100% Verified Correct Answers Guaranteed
A+
After removal of liquid, about how much vapor will remain in the system on a 350 ton R-
11 chiller? - CORRECT ANSWER: 100lbs
Are there drop-in replacements for R-12 systems? Why or why not? - CORRECT
ANSWER: No because the new refrigerants are incompatible with the oils and
lubricants used in R-12 systems.
ASHRAE Standard 15-1994 - CORRECT ANSWER: Requires refrigerant sensor that
will sound alarm and automatically start ventilation system in occupied equipment
rooms where refrigerant from leak will concentrate
At what point in the system should you charge a low pressure system and what should
you start the charge with? - CORRECT ANSWER: Charge through the evaporator
charging valve as this is the lowest point on a low pressure system. First charge the
system with vapor until the refrigeration saturation temperature reaches 36 degrees F or
the vapor pressure reaches 16.9" Hg vacuum
Bubble Point - CORRECT ANSWER: Occurs when saturation temp in condenser
changes refrigerant from vapor to liquid
Compound Gauge - CORRECT ANSWER: Typically blue and measures low pressure
(psig) and vacuum (inHg).
Compressor - CORRECT 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 - CORRECT ANSWER: Rejects heat from system and changes refrigerant
from high-temp, high-pressure vapor into high-pressure, high-temp liquid
Describe two ways to speed up recovery - CORRECT ANSWER: Pack the recovery
cylinder in ice and/or apply heat to the appliance. Recover as much as possible in the
liquid phase.
Dew Point - CORRECT ANSWER: Occurs when saturation temp in evaporator causes
refrigerant to change from liquid to vapor
Does refrigerant go out of the system in low pressure or does air and moisture go in?
Why? - CORRECT ANSWER: A low-pressure system operates in a vacuum (below
atmospheric pressure) to enter the refrigeration system.
Evaporator - CORRECT 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
Find pressure for R-22 at 70 degree F. - CORRECT ANSWER: 121.4 psi
Find the pressure for R-12 at 80 degrees F. - CORRECT ANSWER: 84.4 psi
Foaming at start-up may be found in what component? What does this mean? -
CORRECT ANSWER: Refrigerant in the oil will cause oil foaming in the compressor at
start-up
High Pressure Gauge - CORRECT ANSWER: Red and measures high side (discharge)
pressure. 0 to 500 psi
How can you check if a tank contains excess air or non-condensables? - CORRECT
ANSWER: Check pressure inside recovery tank after allowing temp of cylinder to
stabilize to room temperature
