MACS CERTIFICATION EXAM
QUESTIONS AND ANSWERS 2026
VERIFIED.
If the mechanic's gauges rise from a vacuum to pressure, what is required? - ANS Additional
recovery
What is the only way to fully clear moisture from the A/C system? - ANS Replacing the
desiccant
Pressure ______ the boiling point - ANS Raises
Vacuum _______ the boiling point - ANS Lowers
What should you do when replacing hoses? - ANS Make sure you have the correct type/size
of tubing
What does GWP stand for? - ANS Global Warming Potential
CO2 is equal to what A/C system? - ANS R-744
@2026/2027 ALLRIGHTS RESERVED.
, HFO-1234yf systems are acceptable in what kinds of vehicles? - ANS Passenger cars, light-
duty trucks, medium-duty passenger vehicles, heavy-duty pickup trucks, and complete heavy-
duty vans
HFO-1234yf systems are not acceptable in what kinds of vehicles? - ANS Heavy-duty trucks,
refrigerated transport, and off-road vehicles such as farm equipment
HFO-1234yf is classified by ASHRAE as what? - ANS A2L- mildly flammable
R-744 systems operate at ___ to ___ times higher than HFC-134a and HFC-152a systems. -
ANS 5 to 10
HFC-152a is ___ - ANS flammable
What are the 2 types of HFC-152a systems? - ANS Direct expansion and secondary loop type
Direct Expansion - ANS Refrigerant directly expands within the evaporator that is located
inside the passenger compartment
Secondary Loop (Open Loop) - ANS A circulating non-flammable fluid replaces the evaporator
which provides isolation between the flammable refrigerant and the passenger compartment
Section 609 of the Clean Air Act gives the EPA authority to do what? - ANS Establish
standards and requirements regarding the servicing of mobile A/C systems
What/who establishes standards specifically for the service of motor vehicle air conditioning
systems (MVAC's)? - ANS Section 609 of the Clean Air Act
How many categories of the Section 608 Certification are there? - ANS 4 types
@2026/2027 ALLRIGHTS RESERVED.
QUESTIONS AND ANSWERS 2026
VERIFIED.
If the mechanic's gauges rise from a vacuum to pressure, what is required? - ANS Additional
recovery
What is the only way to fully clear moisture from the A/C system? - ANS Replacing the
desiccant
Pressure ______ the boiling point - ANS Raises
Vacuum _______ the boiling point - ANS Lowers
What should you do when replacing hoses? - ANS Make sure you have the correct type/size
of tubing
What does GWP stand for? - ANS Global Warming Potential
CO2 is equal to what A/C system? - ANS R-744
@2026/2027 ALLRIGHTS RESERVED.
, HFO-1234yf systems are acceptable in what kinds of vehicles? - ANS Passenger cars, light-
duty trucks, medium-duty passenger vehicles, heavy-duty pickup trucks, and complete heavy-
duty vans
HFO-1234yf systems are not acceptable in what kinds of vehicles? - ANS Heavy-duty trucks,
refrigerated transport, and off-road vehicles such as farm equipment
HFO-1234yf is classified by ASHRAE as what? - ANS A2L- mildly flammable
R-744 systems operate at ___ to ___ times higher than HFC-134a and HFC-152a systems. -
ANS 5 to 10
HFC-152a is ___ - ANS flammable
What are the 2 types of HFC-152a systems? - ANS Direct expansion and secondary loop type
Direct Expansion - ANS Refrigerant directly expands within the evaporator that is located
inside the passenger compartment
Secondary Loop (Open Loop) - ANS A circulating non-flammable fluid replaces the evaporator
which provides isolation between the flammable refrigerant and the passenger compartment
Section 609 of the Clean Air Act gives the EPA authority to do what? - ANS Establish
standards and requirements regarding the servicing of mobile A/C systems
What/who establishes standards specifically for the service of motor vehicle air conditioning
systems (MVAC's)? - ANS Section 609 of the Clean Air Act
How many categories of the Section 608 Certification are there? - ANS 4 types
@2026/2027 ALLRIGHTS RESERVED.
