Refrigerant Global Warming Potential Quiz

Questions and Answers

Which type of refrigerants typically has the lowest global warming potential?

HFOs (correct)

HCFCs

HFCs

CFCs

How does the global warming potential of R-410A compare to carbon dioxide?

It is thousands of times greater

How do the global warming potentials of isobutane (R-600a), propane (R-290), and R-441A compare to the GWPs of HFC-134a, R-404A, and R-410A?

They are significantly lower

What is the state of the refrigerant entering the compressor of a refrigeration system?

Low pressure vapor Signup and view all the answers

Which type of lubricants are HFO refrigerants miscible in?

POE lubricants Signup and view all the answers

Which of the following gases help form the earth's protective shield?

Stratospheric Ozone Signup and view all the answers

What does ozone depletion potential (or 'ODP') measure?

The ability of a substance to destroy ozone in the stratosphere Signup and view all the answers

Which of the following refrigerants have an ozone depletion potential of more than zero?

R-123 Signup and view all the answers

HCFC refrigerants contain which of the following?

Hydrogen, chlorine, fluorine & carbon Signup and view all the answers

What must be done before disposing of any appliance containing a CFC, HCFC, or HFC refrigerant?

Recover the refrigerant Signup and view all the answers

A major system repair is being performed on an R-22 appliance. What CANNOT be done to recharge the appliance?

Top off the unit with R-410A Signup and view all the answers

Chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs) have which of the following in common?

They must be recovered before opening or disposing of appliances Signup and view all the answers

Under EPA's regulations, what standard must reclaimed refrigerant meet before it can be resold?

AHRI 700 Signup and view all the answers

Which of the following appliances is NOT covered by EPA Section 608 regulations?

Desiccant dehumidifiers Signup and view all the answers

EPA does NOT require technicians (or the company employing the technician) to keep which of the following records when disposing of appliances with 5-50 pounds of refrigerant?

The model and serial number of the appliance Signup and view all the answers

What synthetic lubricant is presently used with ternary blends containing HCFCs?

Alkylbenzene Signup and view all the answers

How do refrigerant blends leak from a system?

At uneven rates due to different vapor pressures Signup and view all the answers

In which component of a system does the refrigerant change from a high-pressure vapor to a high-pressure liquid?

Condenser Signup and view all the answers

Which process applies to cleaning refrigerant for immediate reuse by oil separation and single or multiple passes through devices, like replaceable core filter driers, which reduce moisture and acidity?

Recycling Signup and view all the answers

What gas should be used to leak check a system designed for use with R-410A that has been opened for a major system repair?

Pressurized nitrogen Signup and view all the answers

Why is it important NOT to mix different refrigerants in the same container when recovering refrigerant?

The mixture may be impossible to reclaim Signup and view all the answers

Over-evacuation of a system occurs.

False Signup and view all the answers

According to the ASHRAE refrigerant safety classification standard, which of the following designations would be the safest?

A-1 Signup and view all the answers

Why should care be used not to overfill refrigerant storage cylinders?

The internal pressure of the cylinders may rise in heated areas and cause an explosion Signup and view all the answers

The Department of Transportation regulations require which parameter to be recorded on the shipping paper for hazard class 2.2 Nonflammable Compressed Gases?

Number of cylinders of each gas Signup and view all the answers

Which of the following refrigerants has the lowest global warming potential?

R-600 Signup and view all the answers

What characteristic(s) of CFCs and HCFCs make them more likely to reach the stratosphere than most other compounds containing chlorine?

They do not dissolve in water or easily break down in the atmosphere Signup and view all the answers

What characteristic of HFC refrigerants make them damaging to the environment?

They can have very high global warming potentials Signup and view all the answers

Which of the following refrigerants contain chlorine?

R-22 Signup and view all the answers

When working with an appliance containing HCFCs or HFCs, which of the following does NOT require a person to be a Section 608 certified technician?

Rewiring an external electric circuit Signup and view all the answers

Which of the following is not a reason to recover refrigerants?

To avoid violating the warranty on equipment Signup and view all the answers

In which of the following scenarios can refrigerant be vented?

Releasing isobutane from a household freezer Signup and view all the answers

What range is displayed on a high pressure gauge on a service manifold?

0 to 800 psi Signup and view all the answers

Why do EPA regulations require appliances to have a service aperture or process stub?

To make it easier to recover refrigerant Signup and view all the answers

Which of the following releases of a refrigerant is illegal?

Venting refrigerant from a recovery machine or recovery cylinder Signup and view all the answers

Which types of refrigerant can only be sold to persons who have successfully passed the EPA's Section 608 certification exam?

Only ozone-depleting substances used in comfort cooling Signup and view all the answers

What is the center port on a three-port manifold used for?

Recovery, evacuation, and charging Signup and view all the answers

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?

Recovering Signup and view all the answers

You have to leak-check a unit which has lost a complete charge. Which gas(es) would cause the least damage to the environment?

Dry nitrogen Signup and view all the answers

What effect will low ambient temperatures have on recovery?

Increase the recovery time Signup and view all the answers

Which of the following is a reason to heat a system during dehydration?

To decrease dehydration time Signup and view all the answers

When pressurizing a refrigeration system with nitrogen what rule should you always follow?

Use a pressure regulator with a pressure relief valve on the nitrogen cylinder Signup and view all the answers

Under what conditions may you use a disposable cylinder to recover refrigerant?

False Signup and view all the answers

What must be done before shipping any used refrigerant in a cylinder?

Properly label the refrigerant container Signup and view all the answers

What are the characteristics of hydrofluoroolefins (HFOs)?

Non-ozone depleting, and have a low global warming potential Signup and view all the answers

Why are some hydrofluoroolefins (HFO) refrigerants classified as 'A2L'?

They are less flammable than hydrocarbon refrigerants, but most are still mildly flammable Signup and view all the answers

What does ozone in the stratosphere above the earth consist of?

Molecules containing 3 oxygen atoms Signup and view all the answers

Which refrigerant does not contain chlorine?

R-134A Signup and view all the answers

From which of the following does the ozone layer protect the earth?

Ultraviolet radiation from the sun Signup and view all the answers

What is the name of EPA's program that identifies refrigerants with lower overall risks to human health and the environment?

The Significant New Alternatives Policy (SNAP) Program Signup and view all the answers

The date when the production and import of new R-22 in the U.S. ends is?

2020 Signup and view all the answers

Which of the following is a lawful use of HCFC-22?

Servicing existing R-22 systems Signup and view all the answers

Which of the following is considered an unacceptable release of CFC, HCFC, or HFC refrigerant?

Release during vandalism or theft of equipment Signup and view all the answers

Which of the following is a 'high-pressure refrigerant' under EPA's refrigerant recycling regulations?

R-410A Signup and view all the answers

What is a ternary blend refrigerant?

A three-part mixture Signup and view all the answers

Which of the following is not a 'refrigerant' as it is used in Section 608 of the Clean Air Act?

A leak trace gas Signup and view all the answers

How does cooling occur in a direct expansion vapor compression refrigeration system?

When the liquid refrigerant is vaporized Signup and view all the answers

What is the strongest evidence that HCFCs are in the stratosphere?

Measurement of HCFCs in air samples from the stratosphere Signup and view all the answers

Which of the following refrigerant releases is considered a violation of the prohibition on venting?

Release of mixtures of nitrogen and refrigerant from a recovery machine Signup and view all the answers

Although the saturation pressure temperature behavior of two refrigerants might be similar, of all the following characteristics of the refrigerants being compared what must also be considered?

Latent heat of evaporation Signup and view all the answers

Study Notes

Refrigerants and Global Warming Potential

HFOs (hydrofluoroolefins) generally have the lowest global warming potential among refrigerants.
R-410A's global warming potential is thousands of times greater than CO2.
Isobutane (R-600a), propane (R-290), and R-441A have significantly lower global warming potentials than HFC-134a, R-404A, and R-410A.

Refrigerant Characteristics and Behavior

Refrigerant enters the compressor as low-pressure vapor.
HFO refrigerants are miscible in POE (polyolester) lubricants.
Stratospheric ozone contributes to the earth's protective shield against UV radiation.
Ozone depletion potential (ODP) quantifies a substance's capability to destroy ozone in the stratosphere.

Disposal and Recovery Regulations

R-123 and R-22 have an ozone depletion potential greater than zero.
CFCs, HCFCs, and HFCs must be recovered before opening or disposing of any appliance containing them.
EPA regulations necessitate recovering refrigerant before disposing of equipment containing CFC, HCFC, or HFC refrigerants.

EPA Standards and Compliance

Reclaimed refrigerant must meet AHRI 700 standards for resale.
Appliances not covered by EPA Section 608 regulations include desiccant dehumidifiers.
Technicians do not need to keep model and serial numbers of appliances with refrigerant between 5-50 pounds during disposal.

Refrigerant and Equipment Usage

Topping off an R-22 appliance with R-410A is not permitted during major system repairs.
Synthetic lubricants for ternary blends containing HCFCs include alkylbenzene.
Refrigerant blends leak from systems at uneven rates due to differing vapor pressures.

Recovery and Recycling Processes

Refrigerant changes from high-pressure vapor to high-pressure liquid in the condenser.
Recycling involves cleaning refrigerant through oil separation and filtration.
Pressurized nitrogen is used to leak check systems designed for R-410A.

Safety Regulations and Practices

Mixing different refrigerants in the same container makes reclamation impossible.
Care is required not to overfill refrigerant storage cylinders to avoid internal explosions.
EPA requires proper labeling of used refrigerant containers before shipping.

Environmental Impact and Prevention

HFO refrigerants are non-ozone depleting with low global warming potentials.
HFCs can have very high global warming potentials, making them environmentally damaging.
Venting refrigerants from recovery machines is illegal and considered a violation.

Technical Specifications and Equipment Knowledge

High-pressure gauges on service manifolds display a range of 0 to 800 psi.
New recovery equipment must have an EPA-approved certification label.
Short, wide piping connections to vacuum pumps optimize efficiency.

Hydration and Testing Compliance

High-pressure refrigerant containers undergo hydrostatic testing every five years.
Safety data sheets (SDS) should be reviewed when dealing with chemicals and refrigerants.
Incompatible elastomers for seals and gaskets with HFO refrigerants include silicone.

Miscellaneous Key Points

Recovering refrigerant refers to the untested storage of refrigerants in external containers.
Dispose of mixtures of R-410A added to R-22 systems in separate recovery tanks.
The latent heat of evaporation is a critical factor in comparing refrigerants despite similar saturation pressure and temperature behaviors.

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Description

Test your knowledge on refrigerants and their global warming potentials. This quiz covers key concepts related to HFOs, R-410A, and comparisons with other refrigerants. Perfect for those studying environmental science and HVAC systems.