EPA CORE PREP
A single chlorine atom can last in the Stratosphere for 120 years destroying up to _________ ozone molecules A 100,000 B 1,000,000 C 10,000
A 100,000
Before shipping any used refrigerant cylinders, check that the cylinder meets what standards: A Department of Transportation B The Significant New Alternatives Policy (SNAP) C Underwriters Laboratories D All of the above
A Department of Transportation
Which of the following refrigerant has a GWP closest to "1"? A R-22 B R-134a C R-410A D R-1233zd
D R-1233zd
_________________________ is the only EPA approved drop-in replacement for a R-22 system. A R-407C B R-1234yf C Propane (R-290) D The EPA does not approve any substitute refrigerants as direct drop-in replacements to service an R-22 or any other system
D The EPA does not approve any substitute refrigerants as direct drop-in replacements to service an R-22 or any other system
An oil sample should be taken when _____________ A moisture/or acid problems are suspected B oil sludge formation or oil waxing is suspected C residual acidic oil from a burn-out is suspected of containing the replacement oil D all of the above
D all of the above
Changes a low pressure vapor to a high pressure vapor A evaporator B condenser C metering device D compressor
D compressor
Ester-based oils like POE can be mixed with A PAG and mineral oils B paraffinic mineral oils C alkylbenzene oils D no other oils
D no other oils
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 A recovering B reclaiming C reuse D recycle
D recycle
Dew point _________ values are used for charging by suction or evaporator ______________. The relationship of pressures and temperatures are based on the refrigerant's temperature glide. A liquid, superheat B vapor, subcooling C liquid, subcooling D vapor, superheat
D vapor, superheat
For safety, any system designed to contain a flammable hydrocarbon (HC) or HFO refrigerant has to have a leak test before evacuating to _____ microns or lower A 200 B 300 C 400 D 500
D. 500
Recovered refrigerant may be charged into another system owned by a different owner T/F
F: Can only be used by the same owner
ASHRAE has grouped refrigerants by Class, depending on their toxicity level to humans. Class B has a lower Toxicity than Class A T/F
F: Class A is Low Toxicity and Class B is Higher. Also Flammability is indicated by a 1 (no flammability), 2 (low flammability), or 3 (high flammability)
Heating the recovery cylinder will raise its pressure and speed up the recovery process or removal of refrigerant charge from a system T/F
F: Cooling the recovery cylinder will lower its pressure and speed up the recovery process or removal of refrigerant charge from a system.
HFOs are less flammable than hydrocarbon refrigerants but most are still mildly flammable so are classified as A2 T/F
F: HFOs are classified as A2L
It is okay to flush field tubing with liquid refrigerant to clean the tubing after a burn-out is recommended and is lawful T/F
F: It is NOT recommended and is UNlawful
HFCs are made up of hydrogen, fluorine, and carbon and most HFCs are not a high Global Warming Potential (GWP) T/F
F: Most HFCs ARE a high Global Warming Potential (GWP)
Its been a violation of EPA Section 608 regulations to vent HFC's since November 15, 1996 T/F
F: November 15, 1995
Chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) are not ODP substances T/F
F: are ODP substances
The technician can share a refrigerant recovery cylinder for the same type of refrigerant recovered and allow them to mix. For example, if servicing systems using HFC-134a, and HFC-410A they are both HFCs and can be mixed T/F
F: each type of refrigerant recovered should have a separate cylinder. It is important not to mix refrigerants in the same container when recovering as refrigerants that are mixed may be impossible to reclaim and there may be an added cost to have them destroyed.
HFO refrigerants contain fluorine making them more flammable than HC (hydrocarbon) refrigerants. T/F
F: fluorine making them less flammable
The EPA's Significant New Alternatives Policy (SNAP) Program identifies refrigerants with higher overall risks to human health and the environment. T/F
F: identifies refrigerants with lower overall risks to human health and the environment.
The chlorine in CFCs and HCFCs will dissolve in water T/F
F: not dissolve in water
What is the Significant New Alternatives Policy (SNAP) Program? A EPA's program that identifies refrigerants with lower overall risks to human health and the environment. B Covers only CFC and HCFC refrigerants used in residential air conditioning. C Relates to CFC and HCFC refrigerants used in commercial air conditioning. D Covers only CFC and HCFC refrigerants used in industrial process refrigeration.
A EPA's program that identifies refrigerants with lower overall risks to human health and the environment.
EPA has divided refrigerated appliances into ____________ groups A Five B Six C Three D Four
A Five Small Appliances (TYPE I) Low Pressure appliances (TYPE III) Medium Pressure Appliances (TYPE II) High Pressure Appliances (TYPE II) Very High Pressure Appliances (TYPE II)
__________________ makes refrigerants a little less harmful to the stratospheric ozone A Hydrogen B Chlorine C Fluorine D Carbon
A Hydrogen
Refrigerant recovery and/or recycling equipment manufactured after ____________________ must be certified and labeled by an EPA-approved equipment testing organization to meet EPA standards. A November 15, 1993 B November 15, 1995 C July 1, 1992 D November 14, 1994
A November 15, 1993
HFO refrigerants are miscible in _____ A POE Lubricants B mineral oils C alkylbenzene (AB) oil D All
A POE Lubricants
Which refrigerant contains chlorine? A R-12 B R-1234yf C R-134a D none of them
A R-12
A system is considered dehydrated when _________________ A a micron-gauge shows you have reached and held a vacuum of 500 microns or less with the vacuum pump isolated from the system B a micron-gauge shows you have reached and held a vacuum of 500 microns, for at least 5 minutes, while the vacuum pump is operating C the manifold suction gauge is bottomed-out at 29.9 in. hg at least an hour D the vacuum pump sound is indicating that nothing else is being pumped out
A a micron-gauge shows you have reached and held a vacuum of 500 microns or less with the vacuum pump isolated from the system
EPA regulations require appliances to have ________________ A a service aperture or process stub B purge valves or purge units C king valves D oversized filter driers
A a service aperture or process stub
The molecule found in CFC's and HCFC's that depletes ozone is A chlorine B fluorine C carbon D Hydrogen
A chlorine
Changes a low-pressure liquid to a low-pressure vapor A evaporator B condenser C metering device D compressor
A evaporator
When leak checking a system, NEVER pressurize the system with oxygen or compressed air. When mixed with some refrigerants or compressor oil, oxygen or compressed air can cause an explosion. To determine the safe pressure for leak testing, check the equipment data plate for the maximum _________________ A low-side test pressure value B high-side test pressure value
A low-side test pressure value
Dehydration is complete when the vacuum gauge/indicator shows that you have reached and held the required vacuum of 500 microns or less. If the pressure increases then stops for a few minutes then rises more, there is probably ____________ A moisture left in the system. B there is probably a leak.
A moisture left in the system.
_________ means to remove refrigerant, in any condition from a system and store it in an approved recovery cylinder or container. A recover B reclaim C reuse D recycle
A recover
Bubble and Dew Points Zeotropic and some near-azeotropic blends use bubble and dew points to indicate condensing and evaporation temperatures on a pressure-temperature chart. Dew point (vapor) values are used for charging by suction or evaporator _____________. The relationship of pressures and temperatures are based on the refrigerant's temperature glide. A superheat B subcooling
A superheat
HFCs ________ A will not damage stratospheric ozone, but have a high GWP. B will damage stratospheric ozone and have a low GWP. C will not deplete stratospheric ozone and have a low GWP. D are only harmful to ground level ozone.
A will not damage stratospheric ozone, but have a high GWP
Which type of refrigerant contains no chlorine? A CFCs B HFCs C HCFCs D HFCSs
B HFCs
Safety/General: When pressurizing a system with nitrogen, you should always charge through a pressure regulator and a relief valve in the downstream line from the pressure regulator. When using more than one pressure relief valve, they _________________ A MUST be installed in series to each other B MUST be installed in parallel to each other
B MUST be installed in parallel to each other
Which international agreement (Treaty) regulated the production and use of CFCs, HCFCs, halons, methyl chloroform, and carbon tetrachloride? A Kyoto Treaty B Montreal Protocol C Council of Nicaea D Treaty of Ghent
B Montreal Protocol
Technicians have been required to be certified to service, maintain, or dispose of appliances containing regulated refrigerants since A November 14, 1992 B November 14, 1994 C November 24, 1992 D November 24, 1994
B November 14, 1994
An example of an HCFC refrigerant is: A R-407C B R-123 C R-134a D R-404A
B R-123
The _____ connects the evaporator to the compressor in a refrigeration system A Discharge Line B Suction Line C Liquid Line
B Suction Line
Changes a high-pressure vapor to a high-pressure liquid A evaporator B condenser C metering device D compressor
B condenser
Recover any remaining refrigerant and then render the cylinder useless, then recycle the metal is the proper disposal method for A recovery cylinders B disposable cylinders C reusable cylinders D recyclable cylinders
B disposable cylinders
The EPA considers ______________ the most effective for locating the general area of a small leak A deep vacuum test B electronic or ultrasonic tester C halide torch D audible sound
B electronic or ultrasonic tester
Low ambient temperatures ______________ recovery time A decrease B increase C no effect on D saturate
B increase
There are two basic types of recovery devices: "System-dependent" (____________) which captures refrigerant with the assistance of components in the appliance from which refrigerant is being recovered and "Self-contained" (____________) which has its own means to draw the refrigerant out of the appliance A active, passive B passive, active
B passive, active
__________ returns the refrigerant to new product specifications and requires chemical analysis to verify purity to AHRI-700 standards A recovering B reclaiming C reuse D recycle
B reclaiming
Bubble and Dew Points Zeotropic and some near-azeotropic blends use bubble and dew points to indicate condensing and evaporation temperatures on a pressure-temperature chart. Bubble point (liquid) values are used when charging by condenser ________________ A superheat B subcooling
B subcooling
The release of any CFC, HCFC, HFC or HFO refrigerant during the service, maintenance, repair, ________________ is illegal. A the installation of gauges equipped with low loss fittings B theft of equipment C the connection of a recovery machine with low loss fittings D all of the above
B theft of equipment
Bubble point _________ values are used when charging by condenser ______________. The relationship of pressures and temperatures are based on the refrigerant's temperature glide. A liquid, superheat B vapor, subcooling C liquid, subcooling D vapor, superheat
C liquid, subcooling
Changes a high-pressure liquid to a low pressure liquid A evaporator B condenser C metering device D compressor
C metering device
An ozone molecule contains _____ oxygen atoms A one B two C three D five
C three
After making a major repair, the appliance should be dehydrated by evacuating the system to a minimum of 500 microns. This minimum level is required for HFC systems with POE OIL T/F
T
Azeotropic refrigerant mixtures contain two or more refrigerants. At a certain pressure, an azeotropic mixture evaporates and condenses at a constant temperature. It acts like a single component refrigerant over its entire range. Thus, azeotropic mixtures act as a pure compound T/F
T
Blended refrigerants are normally associated with having what is called "temperature glide". This is due to the blended parts having different pressures for the same saturation temperature. Temperature glide can range a few tenths of a degree to 12 degrees or more. T/F
T
Dehydration: The reason for dehydrating a refrigeration system is to remove water and water vapor, and it is important to follow proper dehydration procedures. If moisture is allowed to remain in an operating refrigeration system, hydrochloric and hydrofluoric acids may form. T/F
T
During evacuation, you may wish to heat the refrigeration system to decrease dehydration time. T/F
T
Factors affecting the speed and efficiency of evacuation are; size of equipment being evacuated, ambient temperature, amount of moisture in the system, the size of the vacuum pump and vacuum lines T/F
T
Fluorinated gases such as the CFCs, HCFCs and HFCs are referred to as High Global Warming Potential gases. T/F
T
HCFC's contain Hydrogen, Chlorine, Fluorine, and Carbon T/F
T
Hydrocarbon (HC) and Hydrofluoroolefin (HFO) refrigerants have the lowest global warming potential compared to CFCs, HCFCs, and HFCs. T/F
T
Hydrocarbon (HC) refrigerants are an elementary compound of hydrogen and carbon. Although flammable. HCs have no ODP and a very small effect on global warming, with GWP values less than 10. T/F
T
If moisture remains in an operating refrigeration system, hydrochloric and hydrofluoric acids may form T/F
T
Most HFC refrigerants, such as R-410A, have global warming potentials thousands of times greater compared to carbon dioxide T/F
T
Recovering refrigerant in the vapor phase, although slower than liquid recovery, will minimize oil loss from the appliance T/F
T
Technicians can only charge used CFC, HCFC, or HFC refrigerants back into the same appliance or into another appliance with the same owner. T/F
T
The GWP of isobutane (R-600a), propane (R-290), and R-441A are significantly lower when compared to the GWPs of HFCs such as R-134a, R-407C, R-404A, and R-410A. T/F
T
The layer of the Stratosphere that protects us from excessive Ultraviolet radiation is comprised of ozone T/F
T
The phase-out for the production and imports of newly manufactured R-22 and HCFC-142b in the U.S. will be in the year 2020. After the phase-out of all HCFC refrigerants in 2030, supplies of those refrigerants for equipment servicing will come from recovered and reclaimed gas. It is not a violation of the refrigerant management regulations under the Clean Air Act to service a system that uses CFCs or HCFCs after the phase-out of those refrigerants. T/F
T
They do not affect the ozone layer but Most HFCs have a very high GWP T/F
T
Three stages of the condenser 1. De-superheats 2. Change of state (Vapor to Liquid) 3. Sub-cools T/F
T
To better define leak rates and service recovery levels the EPA lists refrigerants in four liquid-phase pressure ranges at 104°F condensing temperature. High-pressure refrigerants have a pressure between 155 psig & 340 psig at a liquid-phase temperature of 104°F. T/F
T
To better define leak rates and service recovery levels the EPA lists refrigerants in four liquid-phase pressure ranges at 104°F condensing temperature. Low-pressure refrigerants have a pressure of 30 psig or lower at a liquid-phase temperature of 104°F. T/F
T
To better define leak rates and service recovery levels the EPA lists refrigerants in four liquid-phase pressure ranges at 104°F condensing temperature. Medium-pressure refrigerants have a pressure between 30 psig & 155 psig at a liquid-phase temperature of 104°F. T/F
T
To better define leak rates and service recovery levels the EPA lists refrigerants in four liquid-phase pressure ranges at 104°F condensing temperature. Very high-pressure refrigerants have a pressure over 340 psig at a liquid-phase temperature of 104°F. T/F
T
Very high-pressure refrigerant (R-744) with 0 ODP and a Global Warming Potential (GWP) of 1 (one). T/F
T
When a system is in full vacuum never energize the compressor T/F
T
When chlorine monoxide is found in the stratosphere, it indicates that the ozone layer is being depleted T/F
T
When retrofitting or converting a system to use a different refrigerant, only EPA-approved substitutes can be used. T/F
T
Whether the tank is half full or just a few ounces of liquid, the pressure will be the same. Example, if two tanks are at the same temperature with different amounts of refrigerant, their pressures will be equal. T/F
T
Zeotropic or non-azeotropic refrigerant mixtures are mixtures of components that have different boiling points. This mixture is a blend of refrigerant. The blend may be binary (two-part) or ternary (three-part). Blended refrigerants are normally associated with having what is called "temperature glide". This is due to the blended parts having different pressures for the same saturation temperature. Temperature glide can range a few tenths of a degree to 12 degrees or more. T/F
T
Zeotropic or non-azeotropic refrigerant mixtures are mixtures of components that have different boiling points. This mixture is a blend of refrigerant. The blend may be binary (two-part) or ternary (three-part). T/F
T
Hydrofluorocarbon (HFC) refrigerants contain hydrogen, fluorine, and carbon and have the lowest/no ozone depletion potential but do have an effect on global warming. T/F
T: Examples of HFCs are R-134a, R-410A, R-404A, R-407C, and R-422B.
Hydrofluoroolefin (HFO) refrigerants contain hydrogen, fluorine, and carbon and have no ODP but do have a very small effect on global warming. T/F
T: HFO refrigerants are miscible in POE lubricants. R-1234yf is an HFO refrigerant used in chillers.
Refrigerant will migrate to a compressor's crankcase and mix with the oil when there is a difference between the oil pressure and refrigerant vapor pressure T/F
T: The compressor crankcase heater is used to help prevent this refrigerant migration.
Carbon Dioxide (CO2) is used as the baseline measurement for global warming potential and has a value of _______________ A 0 B 2 C 1 D .1
C 1
Reusable refrigerant containers under high-pressure (above 15 psig) must be hydrostatically tested how often? A 1 year B 3 years C 5 years D 7 years
C 5 years
All CFC, HCFC, HFC, and HFO refrigerant recovery equipment must meet EPA standards. Recovery equipment must be tested according to _________________________________ A AHRI Standard 700 B AHRI Standard 720 C AHRI Standard 740 D AHRI Standard 760
C AHRI Standard 740
Which one has the the highest ODP A HFC BHCFC C CFC
C CFC
Which of the following has the highest Ozone Depletion Potential? A HFOs B HFCs C CFCs
C CFCs
Crop loss, eye disease, and skin cancer have been attributed to; A Depletion of Stratospheric nitrogen B Depletion of Stratospheric chlorine monoxide C Depletion of Stratospheric ozone D Depletion of Stratospheric oxygen
C Depletion of Stratospheric ozone
___________ makes HFO refrigerants less flammable than HC refrigerants A Chlorine B Fhosgene C Flourine D Fractured oxygen (FO)
C Flourine
Silicone elastomers, for use in seals and gaskets, are not compatible with which refrigerants? A HCFCs B CFCs C HFOs D HFCS
C HFOs
Its been a violation of EPA Section 608 regulations to vent CFC's or HCFC's since A June 1, 1992 B June 1, 1993 C July 1, 1992 D July 1, 1993
C July 1, 1992
The _____ connects the condenser to the expansion device A Discharge Line B Suction Line C Liquid Line
C Liquid Line
What provides the cooling in a vapor compression refrigeration system? A The refrigerant turning into a liquid B The compression of the refrigerant vapor C The vaporization of the liquid refrigerant D The condensation of the refrigerant as it gives off heat in the condenser
C The vaporization of the liquid refrigerant
