This website requires certain cookies to work and uses other cookies to help you have the best experience. By visiting this website, certain cookies have already been set, which you may delete and block. By closing this message or continuing to use our site, you agree to the use of cookies. Visit our updated privacy and cookie policy to learn more.
This Website Uses Cookies
By closing this message or continuing to use our site, you agree to our cookie policy. Learn More This website requires certain cookies to work and uses other cookies to help you have the best experience. By visiting this website, certain cookies have already been set, which you may delete and block. By closing this message or continuing to use our site, you agree to the use of cookies. Visit our updated privacy and cookie policy to learn more.
multiple passes through devices, such as replaceable core filter-driers, which reduce moisture, acidity, andparticulate matter.Recycled refrigerant may be charged into the same system or another system with thesame ownership. Recycling equipment must meet AHRI 740 Performance Rating Standard.Reclaimmeans to process refrigerant to a level equal to new (virgin) product specifications as determined bychemical analysis.Reclaimed refrigerants must meet AHRI 700 Standards, before it can be sold.This isnormally preformed at a chemical processing company.Recovery DevicesRefrigerant recovery and/or recycling equipment manufactured after November 15, 1993 must be certified andlabeled by an EPA-approved equipment testing organization to meet EPA standards.An EPA-approvedcertification label is required on all new recovery equipment.There are two basic types of recovery devices:“System-dependent”(passive) which captures refrigerant withthe assistance of components in the appliance from which refrigerant is being recovered, Figure 7."Self-contained”(active) which has its own means to draw the refrigerant out of the appliance, Figure 8.The recovery time will be increased if the appliance is located in low ambient temperatures or long hoses areused between the unit and the recovery machine.Long and small diameter hoses between the unit andrecovery machine should be avoided as they will cause excessive pressure drop and increase recovery time.Upon completion of refrigerant liquid transfer between recovery unit and the refrigeration system, guardagainst trapping liquid refrigerant in the service hose between closed service valves.The technician must have a separate refrigerant recovery cylinder for each type of refrigerant recovered andshould have a separate cylinder for refrigerants known to be mixed.If servicing systems that useHFC-134a, HFC-410A and HCFC-22, then three cylinders are required even though two are HFCs.It isimportant not to mix refrigerants in the same container when recovering as refrigerants that are mixed be maybe impossible to reclaim and there may be an added cost to have them destroyed.Technicians can only charge used CFC, HCFC, or HFC refrigerants back into the same appliance or intoanother appliance with the same owner.Used refrigerant may no longer meet the AHRI standard for virginrefrigerant so it cannot change ownership without being reclaimed.Figure 7. Passive Recovery Bag 12 oz or less.Figure 8. Active Recovery Unit. Courtesy of Appion Inc.
What type of refrigerant is chlorine free?
HFC's
Refrigerant migrates to the compressor crankcase because of a difference in ________ between the refrigerant and the oil
vapor pressure
Which refrigerant is an HCFC? R-22, R-134a, R-410a, R-12
R- 22
Which Refrigerant is an HCFC? R-124, R-134A, R410a, R-12
R-124
What factor(s) affects the speed of evacuation?
- A) the size of the equipment being evacuated
- B) the ambient temperature
- C) the amt of moisture in the system
Systems charged with R-134a should be leak checked with:
pressurized dry nitrogen
HCFC refrigerants contain:
hydrogen, chlorine, fluorine, carbon
Manifold gauge sets are often color coded, when this is done, the low pressure gauge is color coded:
blue
After refrigerant liquid transfer between recovery unit and the system being emptied, you need to avoid trapping:
liquid refrigerant between service valves
When can you use a disposable cylinder to recover refrigerant?
never
CFC refrigerants are so named because they contain the elements:
chlorine, fluorine, carbon
Recovery equipment that relies upon the compressor in the system would be considered:
system-dependant
The EPA requires the installation of a service aperture stub on all appliances using a class I or class II sustance as a refrigerant. The main purpose of this requirement is to make it easier to:
recover refrigerant
When dealing with small systems, how many different refrigerants may be recovered in the same cylinder?
only one
It is important not to mix different refrigerants in the same container because:
the mixture may be impossible to reclaim
Chlorofluorocarbons (CFC's) and hydrochlorofluorocarbons (HCFC's) have which of the following in common?
they must be recovered before opening or disposing of appliances
Refrigerant that is recovered can be returned to:
the same system or other systems owned by the same person without restrictions
An example of a HFC refrigerant is:
R-134a
When transporting cylinders containing used refrigerant, the DOT requires that you:
attach DOT classification tags
Blended refrigerants leak from a system:
in uneven amounts due to different vapor pressures
Which type of refrigerant is the most harmful to stratospheric ozone?
CFC
Long hoses between the unit and the recovery machine should not be used because they cause:
- A) excessive pressure drop
- B) increased recovery time
- C) Increased emissions
If corrosion is found within the body of a relief valve, the valve must be:
replaced
Disposable refrigerant containers are used for ______ refrigerant.
C) virgin
Never use an open flame to heat a refrigerant tank because
- A) it can result in venting refrigerant to the atmosphere
- B) the tank may explode, causing serious injury to people nearby
- C) refrigerant in the tank may decompose, forming a toxic material
If an oil is hygroscopic it means that it:
readily absorbs moisture
The type of oil that is most commonly used in stationary refrigeration applications w/ HFC-134a refrigerant is:
ester oil
Which type of refrigerant is the most harmful to stratospheric ozone?
refrigerants containing bromine
Ozone depletion in the Stratosphere is what type of problem?
global
Under EPA's regulations, what standard must reclaimed refrigerant meet before it can be resold?
ARI 700
Under the EPA's " safe disposal requirements ", who is responsible of making sure that the refrigerant is removed from household refrigerators before they are disposed of:
final person in the disposal chain
Ozone depletion potential, or "ODP," is
a measure of the ability of CFCs' and HCFCs' to destroy ozone
_______ is the process of removing refrigerant in any condition from a system and storing it in a container without necessarily testing or processing it in any way.
recovering
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
Never use oxygen or compressed air to pressurize a system because:
when mixed with compressor oil or some refrigerants, it could explode
Which of the following is an approved "drop-in" service replacement for R-12? HFC-134a, HFC-410a, R-407c, according to the EPA there are no "drop-in" replacements
according to the EPA there are no "drop-in" replacements
The synthetic lubricant presently used with ternary blends containing HCFCs is
alkybenzene
On a typical three port ( three hose) manifold gauge, the center port is used for:
recovery, evacuation and charging
What refrigerant type has the highest ozone depletion potential? HCFCs, HFCs, CFCs
CFCs
What refrigerant has the lowest ozone depletion potential? R-22, R-11, R-12, or R-113
R-22
Which refrigerants must be recovered before opening a system or disposing of a system?
all refrigerants must be recovered
When dehydrating a system, the system can be heated to
decrease the dehydration time
Use _______ to remove ice from the sight glass.
an alcohol spray
What atom of the CFC molecule causes ozone depletion?
chlorine
Refrigerant vapors or mist should not be inhaled because:
they may cause heart irregularities and/or unconsiousness
The high pressure gauge on service manifold sets has a continuous scale, usually calibrated to read from:
0-500psi
P.P.E.'s (gloves, safety glasses, safety shoes, etc.) should always be worn is when:
handling and filling cylinders
"Self-contained" recovery devices:
can capture liquid and/or vapor refrigerant without the assistance of components in the air-conditioning or refrigeration equipment
It is necessary to place a refrigerant label on:
a refrigerant cylinder which is being returned for reclaiming
Before you dispose of any system containing a refrigerant, you must:
recover the refrigerant
Refrigerant leaves the condenser of an operating system as a:
high pressure liquid
Non-Azeotropic refrigerants leak from a system:
in uneven amounts due to different vapor pressures
Whe using nitrogen to pressurize a system, you should always:
charge through a pressure regulator
All recovery equipment currently being made is required to have
an EPA approved certification label
The color code for approved refrigerant recovery cylinders is
yellow tops and gray bodies
All devices used for refrigerant recovery must:
meet EPA standards
Which of the following gases help form the earth's protective shield? chlorine, chlorides, carbon monoxide, stratosphere ozone
stratosphere ozone
Refrigerant cylinders should always be:
- A) free of rust and damage B) color coded to indicate the contentsC) secure
-
It is illegal to:
knowingly release any refrigerant during the service, maintenance, repair or disposal of appliances, with the exception of de minimis releases
When using nitrogen in a system, when is it a violation of the EPA 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
An award of up to what amount may be paid to a person supplying information that leads to a penalty against the technician who is intentionally venting?
$10,000
Ester based oils can be mixed with:
no other oils
Recycling and recovery equipment intended for use with air-conditioning and refrigeration equipment (except for small appliances) must be tested under:
ARI 740
A compound pressure gauge, typically used on the low side of the system, measures pressure in:
psig and inches of mercury
Which of the following human health effects could result from an increase in ultraviolet radiation?
an increase in cataracts cases
When a system will not hold a vacuum after it has been evacuated, then:
the system may be leaking
You can determine safe pressure for leak testing a system from the:
low-side test-pressure data-plate value
Systems charged with R-410a should be leak checked with:
pressurized nitrogen
Which chemicals are controlled by the Montreal Protocol? chlorofluorocarbons, hydrochlorofluorocarbons, halons
chlorofluorocarbons, hydrochlorofluorocarbons, halon
After 1995, any supplies of CFC refrigerant to service existing units in the USA can only come from:
recovery and recycling
A ternary refrigerant blend is a ____ part mixture. two, three, four or five
three
Reusable refrigerant containers that are normally under any pressure above 15 psig, must be hydrostatically tested and date stamped every: 1yr, 2yr, 3yr or 5yr
5 years
Refrigerant recovery during low ambient temperatures will:
slow the recovery process
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.
A system is dehydrated to:
remove water and water vapor
What refrigerant listed is a "low-pressure refrigerant" under EPA's refrigerant recycling regulations? R-22, R-123, R-134a or R-500
R-123
Which of the following is a "high-pressure refrigerant" under EPA's refrigerant recycling regulations? R-11, R-22, R-113 or R-123
R-22
When dealing with small systems, how many different refrigerants may be recovered into the same cylinder?
only one
The evacuation of a system is a method of:
dehydration
This chemical was found in the upper stratosphere and that indicates that the ozone layer is being destroyed. chlorine monoxide, carbon monoxide, carbon dioxide, or nitrogen dioxide
chlorine monoxide
Which refrigerant contains a CFC? R-12, R-22, R-134a, R-410a
R-12
According to the EPA, of the refrigerants listed below, which types of refrigerants will not contribute to global warming? CFCs, HCFCs, HFCs, the all contribute to global warming
they all contribute to global warming
According to the EPA, an oil sample should be taken for which of the following reasons? a new filter-drier has been installed, the system had a leak or a major component failure, system not cooling properly, recycled refrigerant was added to the system
the system had a leak or a major component failure
A refillable refrigerant cylinder must never be filled to more than _______ of its capacity by weight:
80%
Which of the following is a "very high-pressure refrigerant" under EPA's refrigerant recycling regulations? R-22, R-134a, R-13, R-500
R-13
In a vapor compression refrigeration system, cooling occurs when:
refrigerant liquid turns to a vapor
What statement is true about an azeotropic refrigerant mixture? it is always made from just two components., it ha a pressure-temperature curve identical to one of its components., it is a mixture that is always made from at least three component refrigerants., it is a mixture that acts like a single-component refrigerant over its entire range.
It is a mixture that acts like a single-component refrigerant over its entire range
What is one of the most serious results of damage to the ozone layer?
increase in human skin cancer
When moisture exists in an operating system, which of the following is the most likely to occur? copper tubes and fittings will rust, compressor discharge valves will freeze up, acid will form, compressor head pressures will rise
acid will form
Each chlorine atom in the stratosphere ca destroy ______ ozone molecules.
100,000
-
State and local governments can make state laws that:
- follow the clean air act/EPA regulations contain stricter regulations than the clean air act/EPA regulations
It is important not to mix R-22 and R-410a refrigerants in the same container because
the mixture may be impossible to reclaim
The term used to describe the fact that a refrigerant blend has a range of boiling or condensing points at a constant pressure is:
temperature glide
To scrap a disposable cylinder, the internal cylinder pressure should be reduced to at least:
0 psig
What is the best proof that CFCs are in the stratosphere?
measurement of CFCs in air samples from stratosphere
During servicing of a refrigeration system containing R-22, the refrigerant must be:
recovered
Which of the following statements would be considered good service practices for conserving refrigerant? recover or recycle refrigerant, keep systems tight, find and repair leaks
- recover or recycle refrigerant keep systems tightfind and repair leaks
Data shows that chlorine in the stratosphere comes mainly from CFCs rather than from natural sources such as volcanoes because:
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., the rise in the amount of chlorine in the stratosphere matches the rise in CFC emissions., air samples taken from the stratosphere over erupting volcanoes shows that the volcanoes contribute a small quantity of chlorine to the stratosphere when compared to CFC's
It has been illegal to vent substitutes for CFC and HCFC refrigerants since:
november 1995
According to ASHRAE's 1992 refrigerant safety classification, which of the following designations would be the most safe? A-1,
A-3, B-1, B-3A-1
In general, blended refrigerants should be charge:
as a liquid
Equipment covered by EPA regulations include
all air-conditioning and refrigeration equipment using CFC, HCFC of HFC refrigerants
Which atom of the CFC molecule causes ozone depletion? fluorine, chlorine, sodium, helium
chlorine
The proper method of discarding a disposable refrigerant cylinder is to:
assure that all refrigerant is recovered and that the cylinder is rendered useless, then recycle the metal
A hermetic compressor must never be operated when:
there is a dehydration vacuum in the system
Of the items listed below, which is (are) violation(s) of the clean air act? falsifying or failing to keep required records. failing to reach required evacuation levels before opening or disposing of appliances., knowingly releasing CFC or HCFC refrigerants or their substitutes while preparing appliances
all of the above
When evacuating a system, the hoses should be:
as short in length and as large in diameter as possible
To obtain an accurate vacuum readings during system evacuation, the system vacuum gauge should be located:
as far from the vacuum pump as possible
Refrigerant that enters the expansion or throttling device (also known as the metering device) is a: saturated vapor, superheated vapor, mixture of vapor and liquid, liquid
liquid
Even though R-22 is considered non-toxic, it:
is lighter than air, can cause asphyxia, is a class I refrigerant, can be detected by its colorcan cause asphyxia
R-410A is not a typical blended refrigerant because: it is a near azeotropic refrigerant., it can be charged as either a liquid or vapor., while it has a 400 series refrigerant number it behaves like a 500 series refrigerant
all of the above are true
Never overfill refrigerant storage cylinders because:
the internal pressure of the cylinders may rise in heated areas and cause an explosion
Of the refrigerants listed below, which has the lowest ozone depletion potential? R-22, R-11, R-12, R-113
R-22
Which refrigerant contains a CFC? R-500, R-410A, R-134A, R123
R-500
Which refrigerant is an HCFC? R-123, R-134A, R-410A, R-12
R-123
Of the refrigerants listed, which has the lowest ozone depletion potential? R-22,
R-123, R-134A, R-502R-134A
"Self-contained" recovery devices:
can capture liquid and/or vapor refrigerant without the assistance of components in the air-conditioning or refrigeration equipment
The Montreal Protocol is:
a treaty among nations that controls production of CFCs and HCFCs
What gas(es) would cause the least damage to the environment during a leak check? dry nitrogen and R-22, dry nitrogen and R-12, compressed air and R-12, dry nitrogen
dry nitrogen
According to the EPA, a _______ leak detection method is considered to be the most effective for locating the general area of a small leak.
electronic or ultrasonic tester
Measuring the system's final vacuum is always done with:
the system isolated and the vacuum pump heated
Which safety precaution(s) should always be followed: never apply an open flame to a refrigerant cylinder, never cut or weld any refrigerant line when refrigerant is in the line, never use oxygen to purge lines or to pressurize a system
all of the above
If a technician has a system where some R-502 was added to an R-22 system. The technician should:
recover all the refrigerant into a separate tank
What refrigerant(s) must be recovered before opening a system or disposing of a system?
all refrigerants must be recovered
During servicing of a refrigeration system containing R-12, the refrigerant must be:
recovered
Refrigerant that enters the compressor, under normal operating conditions, is a:
low pressure vapor
According to the EPA, when dealing with customer complaints regarding additional costs due to refrigerant recovery efforts, the technician should:
- explain that refrigerant recovery is necessary to protect human health and the environment explain that refrigerant recovery is required by federal(and in some cases state and local) lawsinform the customer that professional service personnel are duty bound to follow the law and to protect the evvironment
Refrigerant entering the compressor of a refrigeration system is a:
superheated vapor
According to EPA regulations, which of the following procedures is not an approved technique for system cleanup after a burnout?
Installing a suction-line filter-drier, flushing with liquid refrigerant to clean tubing, triple evacuation, deep vacuum evacuationflushing with liquid refrigerant to clean tubing