A2L's-HVAC-R Test: Basic science &
A2L's Test Questions Fully Solved.
What is refrigeration? - Answer The transfer of heat from one place to another by a change
of state of a liquid.
What is refrigeration as it pertains to air conditioning? - Answer The process of transferring
heat from a place it is not wanted to a place where we don't care.
How is temperature defined? - Answer As the measurement of the "Intensity" of heat, but
does not in anyway indicate the quantity of heat.
What is a British thermal unit (BTU)? - Answer the heat required to raise 1 pound of water by
1 degree Fahrenheit
Most, if not all, 2L refrigerants still fall under the jurisdiction of? - Answer EPA Section 608
DOT regulations require refrigerant cylinders containing over _____________ of a 2L refrigerant
to be equipped with a pressure relief valve instead of a rupture disc. - Answer 2.2 lbs.
What dictates how many total cubic feet of a refrigerant may be stored in a location? - Answer
-The refrigerant concentration limit (RCL),
-Safety classification,
-Size of the storage space,
-The risk mitigation systems
If a system is charged with a flammable refrigerant, the equipment must have? - Answer red
(Pantone® Matching System (PMS) #185) markings on the service and access
Hydrogen fluoride can be visibly detected at concentrations as low as _____________________
in air as white fumes. - Answer 1 ppm (part per million)
The human nose can detect the presence of HF at ________ in air and there is a noticeable
irritation at ____________. - Answer 0.3 ppm, 3 ppm
, When fluorinated refrigerants decompose, they can also form a short-lived gas called When
fluorinated refrigerants decompose, they can also form a short-lived gas called? - Answer
carbonyl fluoride, COF2 .
What is Heat of Combustion? - Answer a measurement of the amount of heat released when
a substance, in this case, a refrigerant, burns
Class 2L refrigerants have a much ______ heat of combustion than A3 refrigerants. - Answer
lower
The minimum ignition energy (MIE) - Answer the minimum electrical spark energy, in
millijoules (mJ), required to ignite a flammable gas/air mixture
Burning velocity - Answer the rate at which a flame front spreads relative to the unburned
gas ahead of the flame.
2L refrigerants have a burning velocity of ____________________________ or less, making
them less likely to sustain combustion after the initial ignition source has been removed. -
Answer 10 cm/s (3.9 inches per second)
Refrigerant Concentration Limits (RCL) - Answer used to determine the maximum
concentration of a refrigerant allowed in an occupied space.
lower flammability limit (LFL) - Answer the minimum concentration of a flammable
substance, in this case a refrigerant, that is capable of ignition when there is a sufficient mixture
of air and the substance.
Refrigerant flammability is determined by - Answer ASHRAE-modified ASTM E-681
Flammability test
The process of transferring refrigerant from a sealed system to a refillable cylinder (recovery
tank) approved by the Department of Transportation (DOT) is called; - Answer recovery
If different refrigerant types are mixed in the same tank, the mixture may not be able to be
recycled or reclaimed and may have to be; - Answer destroyed at the owner's expense.
Department of Transportation (DOT) standards require that a recovery tank should not be fill
beyond what percent of its capacity? - Answer 80%
A2L's Test Questions Fully Solved.
What is refrigeration? - Answer The transfer of heat from one place to another by a change
of state of a liquid.
What is refrigeration as it pertains to air conditioning? - Answer The process of transferring
heat from a place it is not wanted to a place where we don't care.
How is temperature defined? - Answer As the measurement of the "Intensity" of heat, but
does not in anyway indicate the quantity of heat.
What is a British thermal unit (BTU)? - Answer the heat required to raise 1 pound of water by
1 degree Fahrenheit
Most, if not all, 2L refrigerants still fall under the jurisdiction of? - Answer EPA Section 608
DOT regulations require refrigerant cylinders containing over _____________ of a 2L refrigerant
to be equipped with a pressure relief valve instead of a rupture disc. - Answer 2.2 lbs.
What dictates how many total cubic feet of a refrigerant may be stored in a location? - Answer
-The refrigerant concentration limit (RCL),
-Safety classification,
-Size of the storage space,
-The risk mitigation systems
If a system is charged with a flammable refrigerant, the equipment must have? - Answer red
(Pantone® Matching System (PMS) #185) markings on the service and access
Hydrogen fluoride can be visibly detected at concentrations as low as _____________________
in air as white fumes. - Answer 1 ppm (part per million)
The human nose can detect the presence of HF at ________ in air and there is a noticeable
irritation at ____________. - Answer 0.3 ppm, 3 ppm
, When fluorinated refrigerants decompose, they can also form a short-lived gas called When
fluorinated refrigerants decompose, they can also form a short-lived gas called? - Answer
carbonyl fluoride, COF2 .
What is Heat of Combustion? - Answer a measurement of the amount of heat released when
a substance, in this case, a refrigerant, burns
Class 2L refrigerants have a much ______ heat of combustion than A3 refrigerants. - Answer
lower
The minimum ignition energy (MIE) - Answer the minimum electrical spark energy, in
millijoules (mJ), required to ignite a flammable gas/air mixture
Burning velocity - Answer the rate at which a flame front spreads relative to the unburned
gas ahead of the flame.
2L refrigerants have a burning velocity of ____________________________ or less, making
them less likely to sustain combustion after the initial ignition source has been removed. -
Answer 10 cm/s (3.9 inches per second)
Refrigerant Concentration Limits (RCL) - Answer used to determine the maximum
concentration of a refrigerant allowed in an occupied space.
lower flammability limit (LFL) - Answer the minimum concentration of a flammable
substance, in this case a refrigerant, that is capable of ignition when there is a sufficient mixture
of air and the substance.
Refrigerant flammability is determined by - Answer ASHRAE-modified ASTM E-681
Flammability test
The process of transferring refrigerant from a sealed system to a refillable cylinder (recovery
tank) approved by the Department of Transportation (DOT) is called; - Answer recovery
If different refrigerant types are mixed in the same tank, the mixture may not be able to be
recycled or reclaimed and may have to be; - Answer destroyed at the owner's expense.
Department of Transportation (DOT) standards require that a recovery tank should not be fill
beyond what percent of its capacity? - Answer 80%
