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WorksheetsA2L Refrigerant
Total questions: 50
Worksheet time: 25mins
The minimum concentration of a refrigerant that can propagate a flame through a consistent mixture of the refrigerant and air is known as the;
acute toxicity exposure limit (ATEL)
immediately dangerous to life or health concentration (IDLH)
lower flammability limit (LFL)
upper explosive limit (UEL)
Refrigerant cylinders should be transported in the upright position to ensure;
easier access in the event of an accident.
the cylinder label is visible during a DOT inspection.
the pressure relief valve is in contact with the vapor space of the cylinder.
the refrigerant vapor will condense to a liquid at the bottom of the tank.
Tools used during the installation or service of systems charged with a flammable refrigerant must be;
flushed with liquid refrigerant before and after use.
listed as “approved for use” in the manufacturer’s installation manual.
pressure tested with the refrigerant to be used to ensure compatibility.
rated for use with flammable refrigerants.
The first stage of the evacuation process which removes non-condensables from a system is called;
degassing.
dehydration.
recovery.
recycling.
Once a flammable refrigerant has been recovered and stored in a recovery cylinder;
it can be taken a safe distance from the jobsite and vented to the atmosphere.
it must be placed a safe distance away from the work area before a system repair or installation is started.
it must be placed in ice to ensure it stays below the refrigerant’s ignition temperature.
it should be returned to a reclamation facility prior to beginning the installation of new equipment.
In a vapor-compression refrigeration circuit, the term non-condensable is used to describe;
a refrigerant oil that will not vaporize in the compressor.
any gas that will not condense to a liquid.
any liquid that will not condense to gas.
any refrigerant that will not mix with the system oil.
Which of the following can affect the speed and efficiency of an evacuation?
The capacity of the vacuum pump and hoses being used.
The fin spacing (fins per inch or FPI) on the condenser and evaporator coils.
The location of the electrical disconnect and the supply voltage to the system.
The type of refrigerant and oil inside of the system.
Which of the following refrigerants is exempt from the EPA’s recovery mandate?
R-32
R-290
R-454B
R-1234yf
Which one of the following refrigerants is classified as an A3 refrigerant?
R-32
R-290
R-717
R-1234yf
Atmospheric pressure (0 psig) is equal to approximately;
25 inches of mercury.
500 microns.
760,000 inches of mercury.
760,000 microns.
To avoid fractionation, blended refrigerants should be;
charged as a liquid.
charged as a vapor.
used only when the ambient temperature is above 65°F.
used only when the ambient temperature is below 55°F.
An uppercase letter designation (R-407A, R-407B, R-407C) is used when refrigerant blends are;
composed of different refrigerants, but with the same percentages of each.
composed of different refrigerants but have the same thermodynamic properties.
composed of the same refrigerants but manufactured by different companies.
composed of the same refrigerants, but with different percentages of each.
Flammable refrigerant cylinders must have a;
dip tube to allow for liquid transfer.
one-time pressure relief valve.
permanently installed pressure/temperature gauge.
red band on the top of the container.
During the brazing process:
a low-pressure purge with an inert gas, such as nitrogen, should be used.
a low-pressure purge with refrigerant vapor should be used.
the system pressure should be kept at 5-10 psig.
the system should be kept in a deep vacuum.
Which of the following refrigerant safety classifications is most hazardous in terms of flammability and toxicity?
A. A2L
B. A2
C. B2L
D. B3
Which of the following refrigerants has the lowest global warming potential (GWP)?
R-32
R-290
R-404A
R-454B
Which of the following should be done prior to beginning the recovery process?
Change the oil in the vacuum pump.
Inform the local authority having jurisdiction.
Purge air from the refrigerant hoses to prevent refrigerant contamination.
Vent the contents of the recovery tank to the atmosphere to ensure it is empty.
When the manufacturer’s literature is not available, the industry-accepted evacuation level for most HVACR equipment is:
0 psia.
0 psig.
500 microns.
15,000 microns.
When working with A2L refrigerants, which one of the following is not an approved leak detection method?
Electronic leak detector
Halide leak detector
Microfoam solution (bubbles)
Ultrasonic leak detector
When brazing a system that has been charged with an A2L refrigerant;
NFPA 704 hazard placards must be placed in visible locations around the perimeter of the jobsite.
the refrigerant tubing should be pressurized with air to stabilize the inner walls.
the system charge must be vented to the atmosphere before beginning.
the system should be swept with nitrogen to ensure that there is no residual refrigerant.
Refrigerants that have a lowercase letter designation, such as R-134a indicate a(n);
azeotropic blend.
isomer.
olefin.
zeotropic blend.
Which of the following will allow the largest flow to a vacuum pump?
One 3/8-inch hose
Two 1/4-inch hoses
Two 1/2-inch hoses
Two 3/8-inch hoses
Which of the following is classified as an A2L refrigerant?
R-290
R-441A
R-744
R-1234yf
Refrigerant cylinders equipped with a dip tube;
allow liquid or vapor to be charged with the cylinder in the upright position.
are not allowed to be used with flammable refrigerants.
have an internal pressure and temperature monitoring device.
have a single ½-inch hose connection with a left-handed thread.
When using a flammable refrigerant as a trace gas for leak detection, the amount must not exceed;
10% of upper explosive limit (UEL) of the refrigerant.
25% of the lower flammability limit (LFL) of the refrigerant.
25% of upper explosive limit (UEL) of the refrigerant.
35% of the lower flammability limit (LFL) of the refrigerant.
Hydrogen fluoride (HF) can form when:
any chlorine-containing refrigerant undergoes complete or incomplete combustion, or thermal decomposition.
any chlorine-containing refrigerant undergoes fractionation.
any fluorine-containing refrigerant undergoes complete or incomplete combustion, or thermal decomposition.
any fluorine-containing refrigerant undergoes fractionation.
Which of the following must be recorded on the label of A2L equipment upon completion of a system installation?
Date that the pressure test and evacuation were completed.
Manufacturer’s technician support phone number or website.
Number of technicians on the jobsite.
Technician’s EPA certification number.
EPA Section 608 regulations require that if a system is charged with a flammable refrigerant, the equipment must have;
an EPA-approved liquid refrigerant receiver marked with a red stripe.
red refrigerant caps on all service ports.
red markings on service valves and tubing.
red markings on the metering device, condenser, and evaporator coils.
Which of the following is/are used to determine the maximum concentration of a refrigerant allowed in an occupied space?
Burning velocities
Heat of combustion
Minimum Ignition Energy (MIE)
Refrigerant Concentration Limits (RCL)
The EPA program that evaluates and approves substitute refrigerants for use is;
ASHRAE
GreenChill
Section 608
SNAP
To reduce the chances of a possible ignition source from being introduced into the work area of a flammable refrigerant system;
allow only two certified technicians per jobsite.
designate a safe perimeter around the work area.
install the equipment in an area with limited access.
wear self-contained breathing apparatus (SCBA) at all times.
DOT regulations require refrigerant cylinders containing over 2.2 lbs. of a 2L refrigerant to be equipped with:
a dip tube.
a fire suppression mechanism.
a pressure relief valve.
locking valve caps.
Which of the following is true regarding lower flammability HFO refrigerants?
They can be vented to the atmosphere.
They cannot be reclaimed.
They must be charged as a liquid.
They must be recovered.
Which of the following refrigerants is an HFO?
R-32
R-290
R-600a
R-1234yf
The rate at which a flame front spreads relative to the unburned gas ahead of the flame is called the:
burning velocity.
heat of combustion.
lower flammability limit.
minimum ignition energy.
Which of the following is one of the factors used to determine the maximum allowable charge of an A2L system?
The average relative humidity of the installation space.
The outdoor ambient air design temperature.
The cubic feet of airspace served by the equipment.
The size of the supply and return air ducts.
Upon completion of an A2L system installation;
a permanent label must be placed on the system to show required service dates.
the fire suppression system must be tested to ensure proper operation.
the manufacturer's literature must be kept on file by the contractor performing the installation.
the manufacturer's literature should be reviewed with and left with the equipment owner.
If the pressure relief valve has been activated on a system that is charged with a flammable refrigerant;
a local code official must be informed, and a report of the incident must be kept on file.
a report must be filled out and sent to the EPA.
it should be replaced with a new valve with the same ratings.
the system charge should be recovered, and the compressor oil changed.
Which of the following is an example of an industry-accepted mitigation strategy that can be used when installing equipment that is charged with an A2L refrigerant?
Installation of smoke/fire/CO detectors
Permanent space ventilation
Posting NFPA placards near the installation location
Secondary service entrance to the equipment space
Refrigerant piping for an A2L system that is installed inside of a wall or floorspace, where it passes through joists or studs, must be;
electrically grounded.
double-wall, type R copper.
protected by a strike plate or shielding.
supported every 6 feet with an approved fitting.
After installation, the refrigerant piping for an A2L system must be;
cleaned with an alcohol-based solution to remove any oils or grease.
pressurized with dry nitrogen to perform a leak test.
pressurized with a non-flammable refrigerant (A1) to perform a leak test.
vibration-tested using whichever method is approved by the local code authority.
After reaching the required recovery level on a system that is charged with an A2L refrigerant;
a nitrogen sweep should be done to remove any residual refrigerant vapor.
an alcohol-based solution must be used to remove any oils or grease.
the refractive index of the compressor oil must be tested.
the system must stand idle for 60 minutes prior to beginning any work on it.
Patterns of adding refrigerant to an A2L system of at least once per three-year period, should be considered;
a symptom of a faulty compressor.
proof of a leak.
verification of the efficiency any installed mitigation strategies.
within the range of permissible emissions.
When performing service on the electrical components of a system that is charged with an A2L refrigerant, which of the following is an unacceptable practice?
Discharge all capacitors with a screwdriver prior to beginning any repair.
Replace components only with parts specified by the manufacturer (OEM).
Verify that the system is properly grounded prior to beginning any repair.
When the system is de-energized, employ proper lock out/tag out procedures.
Intrinsically safe electrical components;
can be operated in wet locations or underwater.
can be worked on while live within a flammable atmosphere.
can only be operated while being monitored by a service professional.
can operate outside of their listed design conditions for a brief period.
When installing a system that is charged with a flammable refrigerant, which of the following can be installed to energize mitigation responses?
Active refrigerant sensor
Combustible gas leak detector
Passive refrigerant sensor
Wi-Fi-enabled digital thermostat
Before beginning the installation of a system that is charged with an A2L refrigerant;
a local code official must approve the site of the installation.
NFPA 704 hazard placards must be placed in visible locations around the perimeter of the jobsite.
permanent mechanical ventilation must be installed in the structure.
verify that all the components being installed are designed for use with A2L refrigerants.
Which of the following must be done when removing an existing R-410A system and installing a system that is charged with an A2L?
A technician must install a temporary sprinkler system which will cover the entire work area.
All gas-burning appliances in the installation area must be replaced with electric appliances.
The exposed surfaces of the jobsite must be watered down to ensure that they remain damp for the duration of the installation.
The installation area must be evaluated to ensure it meets the manufacturer’s specifications and local building codes.
Where can information regarding recommended personal protective equipment (PPE) for a specific refrigerant be found?
It is published by the Federal Trade Commission (FTC).
It will be listed on the EPA’s website.
The refrigerant wholesaler must provide the information when the refrigerant is purchased.
The Safety Data Sheets (SDS) for the refrigerant.
When a technician is disposing of a piece of equipment that was charged with a flammable refrigerant, it must have a label affixed to it which states:
the date that equipment was decommissioned and the refrigerant was recovered.
the equipment manufacturer and where it was purchased.
the disposal location and the reason for disposal.
the location where the equipment was installed, and where it was disposed of.
