A2L COMPREHENSIVE EXAMS ANSWERS AND
QUESTIONS SET A+
✔✔Certain refrigerants, such as ___________ and ___________ are exempt from the
EPA's recovery mandate. - ✔✔R-290 (propane), R-600a (isobutane)
✔✔Never fill a recovery tank beyond ___________ of its capacity - ✔✔80%
✔✔The two most common non-condensables found in HVACR systems are
___________ and ___________ - ✔✔air, nitrogen
✔✔The industry standard target for evacuation is ___________ - ✔✔500 microns
(29.98 inHG)
✔✔A ___________ should always be used to measure the vacuum level. - ✔✔digital
micron gauge
✔✔When using an A2L, A2, or an A3 as a refrigerant trace gas, the amount must not
exceed ___________ % of the lower flammability level (LFL) for the refrigerant as listed
in ASHRAE Standard 34. - ✔✔25
✔✔Most, if not all, A2L refrigerants still fall under the jurisdiction of ___________ -
✔✔EPA 608
✔✔When working with any refrigerant, flammable or non-flammable, always refer the
___________ or specific hazard mitigation actions. - ✔✔Safety Data Sheets (SDS)
✔✔DOT regulations require refrigerant cylinders containing over 2.2 punds of an A2L
refrigerant to be equipped with a ___________ instead of a rupture disc. - ✔✔pressure
relief valve
✔✔OSHA requires that if flammable refrigerant cylinders are to be stored in an
enclosure, the enclosure be ___________ and ___________ - ✔✔secure, ventilated
, ✔✔When servicing or installing equipment charged with a flammable refrigerant, the
jobsite should be evaluated for safety hazards, such as possible ignition sources or the
presence of flammable vapors ___________. - ✔✔prior to beginning
✔✔Specific applications and use limitations for the installation of A2L equipment can be
found in the___________ - ✔✔manufacturers literature
✔✔When working with a flammable refrigerant, recommended PPE can be found in the
___________. - ✔✔SDS
✔✔With proper ventilation on a jobsite or work area, flammable refrigerants can be kept
below their ___________ should a leak occur. - ✔✔Lower Flammability Limit (LFL)
✔✔Accumulation of a flammable refrigerant in a confined space can lead to a
___________ or ___________ - ✔✔sever ignition, asphyxiation
✔✔Underwriters Laboratories (UL) standards require that systems charged with a
flammable refrigerant have a label affixed to the unit that is filled out by ___________ -
✔✔the installing technician
✔✔EPA 608 regulations require that if a system is charged with a flammable refrigerant,
the equipment must have ___________ on the service and access valves which must
extend at least 1 inch in each direction - ✔✔red markings
✔✔___________ is a measurement of the amount of heat released when a substance,
in this case, a refrigerant, burns - ✔✔Heat of Combustion (HOC)
✔✔The ___________ is the minimum electrical spark energy, in millijoules (mJ),
required to ignite a flammable gas/air mixture. - ✔✔minimum ignition energy
✔✔The ___________ of a combustible gas (flammable refrigerant) is the rate at which
a flame front spreads relative to the unburned gas ahead of the flame. - ✔✔Burning
Velocity
✔✔The ___________ is the lowest of three calculated limits for: toxicity, oxygen
deprivation, and/or flammability. - ✔✔Refrigerant Concentration Limit (RCL)
✔✔The ___________ is 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. - ✔✔Lower Flammability Limit (LDL)
QUESTIONS SET A+
✔✔Certain refrigerants, such as ___________ and ___________ are exempt from the
EPA's recovery mandate. - ✔✔R-290 (propane), R-600a (isobutane)
✔✔Never fill a recovery tank beyond ___________ of its capacity - ✔✔80%
✔✔The two most common non-condensables found in HVACR systems are
___________ and ___________ - ✔✔air, nitrogen
✔✔The industry standard target for evacuation is ___________ - ✔✔500 microns
(29.98 inHG)
✔✔A ___________ should always be used to measure the vacuum level. - ✔✔digital
micron gauge
✔✔When using an A2L, A2, or an A3 as a refrigerant trace gas, the amount must not
exceed ___________ % of the lower flammability level (LFL) for the refrigerant as listed
in ASHRAE Standard 34. - ✔✔25
✔✔Most, if not all, A2L refrigerants still fall under the jurisdiction of ___________ -
✔✔EPA 608
✔✔When working with any refrigerant, flammable or non-flammable, always refer the
___________ or specific hazard mitigation actions. - ✔✔Safety Data Sheets (SDS)
✔✔DOT regulations require refrigerant cylinders containing over 2.2 punds of an A2L
refrigerant to be equipped with a ___________ instead of a rupture disc. - ✔✔pressure
relief valve
✔✔OSHA requires that if flammable refrigerant cylinders are to be stored in an
enclosure, the enclosure be ___________ and ___________ - ✔✔secure, ventilated
, ✔✔When servicing or installing equipment charged with a flammable refrigerant, the
jobsite should be evaluated for safety hazards, such as possible ignition sources or the
presence of flammable vapors ___________. - ✔✔prior to beginning
✔✔Specific applications and use limitations for the installation of A2L equipment can be
found in the___________ - ✔✔manufacturers literature
✔✔When working with a flammable refrigerant, recommended PPE can be found in the
___________. - ✔✔SDS
✔✔With proper ventilation on a jobsite or work area, flammable refrigerants can be kept
below their ___________ should a leak occur. - ✔✔Lower Flammability Limit (LFL)
✔✔Accumulation of a flammable refrigerant in a confined space can lead to a
___________ or ___________ - ✔✔sever ignition, asphyxiation
✔✔Underwriters Laboratories (UL) standards require that systems charged with a
flammable refrigerant have a label affixed to the unit that is filled out by ___________ -
✔✔the installing technician
✔✔EPA 608 regulations require that if a system is charged with a flammable refrigerant,
the equipment must have ___________ on the service and access valves which must
extend at least 1 inch in each direction - ✔✔red markings
✔✔___________ is a measurement of the amount of heat released when a substance,
in this case, a refrigerant, burns - ✔✔Heat of Combustion (HOC)
✔✔The ___________ is the minimum electrical spark energy, in millijoules (mJ),
required to ignite a flammable gas/air mixture. - ✔✔minimum ignition energy
✔✔The ___________ of a combustible gas (flammable refrigerant) is the rate at which
a flame front spreads relative to the unburned gas ahead of the flame. - ✔✔Burning
Velocity
✔✔The ___________ is the lowest of three calculated limits for: toxicity, oxygen
deprivation, and/or flammability. - ✔✔Refrigerant Concentration Limit (RCL)
✔✔The ___________ is 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. - ✔✔Lower Flammability Limit (LDL)
