EPA Core
Clean refrigerant for reuse by separating the oil from the refrigerant and removing moisture from the refrigerant by passing it through one or more filter driers, is the definition of;
Recycle
In a vapor compression refrigeration system, cooling occurs when:
Refrigerant liquid turns to a vapor.
Chlorofluorocarbons (CFCs) and Hydrochlorofluorocarbons (HCFCs) have which of the following in common?
they must be recovered before opening or disposing of appliances
An award of up to what amount may be paid to a person supplying information that leads to a penalty against a technician who is intentionally venting?
$10,000
How much can a person be fined per day per violation for knowingly releasing a regulated substance that violates the Clean Air Act?
$44,539
To scrap a disposable cylinder, the internal cylinder pressure should be reduced to at least:
0 psig
A single chlorine atom can destroy how many ozone molecules?
100,000
Each chlorine atom in the stratosphere can destroy ____ ozone molecules.
100,000
When an HFC system with POE oil has been opened for a major system repair, what is the minimum evacuation level that should be achieved before charging the system?
500 microns
what is the state of the refrigerant entering the compressor of an refrigeration system?
Low pressure vapor
what is the component directly following the condenser in a refrigeration system using a thermal expansion valve?
Receiver
To process refrigerant to a level equal to new (virgin) product specifications as determined by chemical analysis defines;
Reclaiming
what must be done before disposing of any appliance containing a CFC, HCFC, or HFC refrigerant?
Recover the refrigerant
During servicing of a refrigeration system containing R-12, the refrigerant must be:
Recovered
what is the term for removing refrigerant in any condition from a system and storing it in an external container without necessarily testing or processing it in any way?
Recovery
After 1995, any supplies of CFC refrigerant to service existing units in the USA can only come from:
Recovery and Recycling
when using nitrogen in repairing a sealed refrigeration system, what should the nitrogen tank always be equipped with?
regulator
when corrosion is found within the body of relief valve the valve must be:
replaced
which of the following gases help from the earth's protective shield?
stratospheric ozone
Refrigerant that is recovered can be returned to:
the same system or other systems owned by the same person without restriction
which of the following is true if a system will not hold a vacuum after it has been evacuated?
the system may be leaking
A system is considered dehydrated when:
the vacuum indicator shows you have reached & held the required finished vacuum
which of the following best describes low loss fittings on refrigerant recovery devices used to recover CFCs, HCFCs, and HFCs?
they can be either manually closed or automatically closed when disconnected to prevent loss of refrigerant from hoses
which of the following statements about "self-contained" recovery device is true?
they remove refrigerant from an appliance without the assistance of components in the appliance
what is the best use for testing with soap bubbles?
to pinpoint refrigerant leaks
how would you remove moisture from refrigerant in a system?
use filter drier
which of the following safety precautions should be adhered to for low-pressure system?
use gloves and safety goggles when working with liquid refrigerant.
Refrigerant migrates to the compressor crankcase because of the difference in _______ between the refrigerant and the oil.
vapor pressure
HFCs :
will not damage stratospheric ozone, but have a high GWP.
the chlorine in CFCs and HCFCs:
will not dissolve in water
In what state should a system be to measure a final system vacuum?
with the system isolated and the vacuum pump turned off
What characteristic(s) of CFCs make them more likely to reach the stratosphere than most other compounds containing chlorine?
Refrigerants that contain chlorine but not hydrogen are so stable that they do not break down in the lower atmosphere after being released. the chlorine or bromine reacts with ozone, causing it to change back to oxygen, thus destroying the ozone layer.
Which type of refrigerant contains no chlorine?
HFCs
what is the state of the refrigerant leaving the receiver in a refrigeration system?
High pressure liquid
what effect will low ambient temperatures have on recovery?
Increase the recovery time
which of the following refrigerant releases is considered a violation of the prohibition on venting?
Release of mixtures of nitrogen and refrigerant that result from adding nitrogen to a fully charged appliance to leak check the appliance.
which of the following repairs would always be considered "major" under EPA's regulations?
Replacement of an evaporator coil
It is best practice to use dry nitrogen to break the vacuum when dehydrating by the triple evacuation method. However, it
Requires a pressure regulator
The EPA can require a technician to demonstrate their ability to perform proper procedures for recovering and/ or recycling refrigerant. failure to demonstrate competency can result in:
Revocation of the technician's certification.
what does ozone depletion potential (ODP) measure
The ability of a substance to destroy ozone in the stratosphere
which of the following factors affect the speed of system dehydration?
The ambient temperature and amount of moisture in the system
To determine the maximum allowable pressure to use when checking a system, check:
The design pressure on the equipment nameplate
It is important not to mix R-22 and R-410A refrigerants in the same container because:
The mixture may be impossible to reclaim.
Whenever dry nitrogen from a portable cylinder is connected to a system, what item is of most importance in consideration of safety?
There is a relief valve in the downstream line from the pressure regulator
Why are some of the hydrofluoroolefin (HFO) refrigerants classified as A2L? a. They have toxicity characteristics. b. They are less flammable than hydrocarbon refrigerants, but most are still mildly flammable. c. They are prohibited for use in the U.S. d. They have ozone depleting potentials and have low global warming potentials.
They are less flammable than hydrocarbon refrigerants, but most are still mildly flammable
Disposable refrigerant containers are used for ______ refrigerent
Virgin
Which of the following are recommended safe work practices when recovering refrigerants?
Wear safety eyewear and butyl-lined gloves when connecting/disconnecting hoses
Approved refrigerant recovery cylinders can be identified by which color code
Yellow tops and gray bodies
what are the two factors that, if present, are most likely to lead to an explosion with hydrocarbon refrigerants?
a sufficient concentration of the refrigerant in the space and an ignition source
The Montreal Protocol is:
a treaty among nations that controls production of CFCs and HCFCs
An ozone molecule contains;
3 oxygen atoms
Reusable refrigerant containers under high-pressure must be hydrostatically tested how often?
5 years
Recover any remaining refrigerant and then render the cylinder useless, then recycle the metal is the proper disposal method for;
Disposable Cylinders
A refrigerant Cylinder designed to hold recovered refrigerant has a:
Grey body and yellow top
Silicone elastomers, for use in seals and gaskets, are not compatible with which refrigerants?
HFOs
the low-side test-pressure data-plate value should be used by technician to determine a safe pressure for:
Leak testing
In general, blended refrigerants should be charged:
Liquid
When a pungent odor is detected during a sealed system recovery and/or repair which of the following is most likely?
A compressor burnout has occured
which of the following has the highest ozone depletion potential?
CFCs
which type of refrigerant has the highest ozone depletion potential (ODP)
CFCs
Which of the following refrigerant has a GWP of 1?
Carbon Dioxide
which of the following gases is used as the baseline measurement for global warming potential?
Carbon Dioxide
The molecule found in CFCs and HCFCs that depletes ozone is:
Chlorine
Which atom of the CFC molecule causes ozone depletion?
Chlorine
Which leak repair category does the EPA define as air-conditioning appliances used to provide cooling in order to control heat and/or humidity in occupied facilities including, but not limited to, residential, office, and commercial buildings?
Comfort cooling
in which component of a system does the refrigerant change from a high-pressure vapor to high-pressure liquid?
Condenser
which international agreement (treaty) regulated the production and use CFCs, HCFCs, Halons, Methyl chloroform and Carbon tetrachloride?
Montreal protocol
What type of synthetic oils are commonly used in new HFC systems and for retrofitting HCFC equipment to HFC refrigerants? a. Polyolester b. Glycol c. Alkyl-benzene d. Mineral Oil
Polyolester
what is the service procedure if the refrigerant in a recovery cylinder is suspected to be contaminated?
Take pressure reading of the cylinder
How should refrigerant cylinders be positioned when they are shipped?
Upright
When using recovery unit the fill level of the recovery tank can be controlled by: 1- a mechanical float switch 2- an electronic shut-off device 3- weight 4- all of the above
all of the above
When evacuating a system, the use of severely oversized vacuum pump could:
cause trapped water to freeze
The condenser:
changes a high pressure vapor to a high pressure liquid
The compressor:
changes a low pressure vapor to a high pressure vapor
The evacuation of a system is a method of:
dehydration
Which gas(es) would cause the LEAST damage to the environment during a leak check?
dry nitrogen
The ozone layer protects the Earth from
ultraviolet radiation from the sun
Which ASHRAE classification means slightly flammable?
A2L
Data shows that chlorine in the stratosphere comes mainly from CFCs rather than from natural sources such as volcanoes because: 1- the rise in the amount of chlorine in the stratosphere matches the rise in the amount of fluorine, which has different natural sources than chlorine. 2- the rise in the amount of chlorine in the stratosphere matches the rise in CFC emissions. 3- Air Samples taken from the stratosphere over erupting volcanoes contribute a small quantity of chlorine to the stratosphere when compared to CFCs. 4- All of the above.
All of the above
Refrigeration technicians who violate the clean air act can: 1- lose their EPA certification. 2- be fined. 3- be required to appear in federal court. 4- all of the above
All of the above
what should be used to remove ice from sight glasses or viewing glasses?
An alcohol spray
What is the Montreal Protocol?
An international treaty that addresses ozone-depleting substances and their alternatives
a very large refrigerant leak can cause suffocation because refrigerants:
Are heavier than air and displace oxygen
Before shipping any used refrigerant cylinders, check that the cylinder meets what standards:
Department of transportation
Crop loss, eye disease, and skin cancer have been attributed to;
Depletion of Stratospheric ozone
what is the significant New Alternatives Policy (SNAP) program?
EPA's program that identifies refrigerants with lower overall risks to human health and the environment.
Which of the following refrigerants is an HFO?
R-1234ze
Which refrigerant is an HCFC?
R-124
An example of an HFC refrigerant is:
R-134a
Of the refrigerants listed below, which has the lowest ozone depletion potential?
R-22
An example of a HFC refrigerant is:
R-410A
Refrigerant can not be called "reclaimed" unless it:
has been chemically analyzed and the refrigerant meets the ARI-700 purity standard
HCFCs contain:
hydrogen, chlorine, fluorine, and carbon
Blended refrigerants leak from a system:
in uneven amounts due to different vapor pressures
what is one of the most serious result of damage to the ozone layer?
increases in human skin cancer
What statement is true about an azeotropic refrigerant mixture?
it is a mixture that acts like a single-component refrigerant over its entire range.
before beginning a refrigerant recovery procedure, it is ALWAYS necessary to:
know the type of refrigerant that is in the system
When using with any solvent, cleaner, chemical or refrigerant, you should review:
material safety data sheets
after recovering refrigerant from a sealed system if nitrogen is used to pressurize or blow debris out of the system, the nitrogen:
may be vented to the ambient air
Ozone Depletion Potential, or "ODP" is
measurement of CFCs and HCFCs ability to destroy ozone
