Introduction to Refrigerants Flashcards

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Questions and Answers

What is the Montreal Protocol?

A document that banned the production of CFCs (correct)

A guideline for refrigerant usage

An international treaty related to global warming

A type of refrigerant

The Montreal Protocol required the United States and other developed countries to stop producing CFC refrigerants by ______________.

January 1, 1996

What does the Environmental Protection Agency (EPA) do?

Enforces regulations for working with refrigerants.

What is the Clean Air Act?

A federal law that includes guidelines, restrictions, and penalties for releasing refrigerants into the atmosphere. Signup and view all the answers

What does CFC stand for?

Chlorofluorocarbons Signup and view all the answers

What does HCFC stand for?

Hydrochlorofluorocarbons Signup and view all the answers

What does HFC stand for?

Hydrofluorocarbons Signup and view all the answers

What are refrigerant blends?

Mixtures of two or more established refrigerants. Signup and view all the answers

Each ______________ can break apart as many as 100,000 ozone molecules before it is neutralized.

chlorine atom Signup and view all the answers

What is temperature glide?

The temperature difference between the vapor and liquid state during evaporation or condensation at a constant pressure. Signup and view all the answers

What is the temperature of the refrigerant in an evaporator when the compressor is running?

About 8F to 12F colder than the evaporator temperature. Signup and view all the answers

What are cryogenic fluids used for?

To rapidly freeze foods to temperatures of -250F to nearly absolute zero. Signup and view all the answers

What characteristics define a good refrigeration lubricant?

Low wax content, high thermal and chemical stability, low pour point, and low viscosity. Signup and view all the answers

Ozone depletion potential is a numeric value assigned to refrigerants to show how harmful they can be to the ozone compared to which refrigerant?

R-11 Signup and view all the answers

Refrigerants that are represented by 400s in the numbering system are called __________.

zeotropes Signup and view all the answers

Refrigerants that are represented by 500s in the numbering system are called ____________.

azeotropes Signup and view all the answers

How can the refrigerant temperature in an air-cooled condenser be estimated?

By adding 30F to 35F to the ambient temperature of air around the condenser. Signup and view all the answers

What governmental body enforces the regulations of the Clean Air Act?

EPA - Environmental Protection Agency Signup and view all the answers

Section _________ of the Clean Air Act requires that all technicians have certification in order to service HVACR equipment.

608 Signup and view all the answers

Which type of refrigerant has the highest ozone depletion potential?

CFCs Signup and view all the answers

HFCs have an ozone depletion potential of _________.

0 Signup and view all the answers

A refrigerant's global warming potential (GWP) is based on the ratio of its warming effect compared to the warming effect of ____________.

carbon dioxide Signup and view all the answers

What classification describes a partially halogenated refrigerant with 0 ODP but high GWP?

HCFCs Signup and view all the answers

Study Notes

Montreal Protocol

Banned production of CFCs in developed countries to combat ozone depletion.
Effective from January 1, 1989.
Required the U.S. and other developed nations to cease CFC production by January 1, 1996.

Regulatory Bodies

Environmental Protection Agency (EPA): U.S. agency enforcing refrigerant regulations.
Clean Air Act: Federal law dictating guidelines and penalties for refrigerant release.

Refrigerant Types

CFCs: Chlorofluorocarbons (e.g., R-11, R-12); known for high ozone depletion potential.
HCFCs: Hydrochlorofluorocarbons (e.g., R-22, R-123); reduced ODP but higher GWP.
HFCs: Hydrofluorocarbons with ODP of 0 (e.g., R-134a, R-152a).
HFOs: Hydrofluoro-olefins; newer refrigerant type with lower environmental impact.
HCs: Hydrocarbons; natural refrigerants with low environmental impact.

Refrigerant Properties and Behavior

Refrigerant blends consist of multiple established refrigerants.
Azeotropic: Blends represented by 500s; behave like single substances during phase changes.
Zeotropic: Blends represented by 400s; changes in composition during phase changes.
Bubble Point: Temperature at which liquid zeotrope begins to boil.
Dew Point: Temperature at which vapor zeotrope begins to condense.
Temperature Glide: Difference between vapor and liquid states during evaporation/condensation.

Temperature Guidelines

Refrigerant in evaporator: 8F to 12F (4C to 7C) colder than evaporator when compressor running.
Same temperature in evaporator and refrigerant when compressor is off.
In air-cooled condensers, refrigerant is 30F to 35F (17C to 19C) warmer than ambient temperature.
In water-cooled condensers, refrigerant is approximately 20F (11C) warmer than outlet water temperature.

Lubricants and Freezants

Good Refrigeration Lubricant: Low wax content, high thermal and chemical stability, low pour point, low viscosity.
Freezants: Cryogenic fluids (e.g., liquid nitrogen, carbon dioxide) used for rapid food freezing, reaching temperatures as low as -250F (-157C).

Environmental Impact and Regulation

Chlorine atoms can destroy up to 100,000 ozone molecules before neutralization.
Ozone Depletion Potential (ODP) is a numeric value indicating refrigerant harm compared to R-11.
HFCs and HCFCs classified based on their ozone depletion potential and global warming potential (GWP).

Certification and Compliance

Section 608 of the Clean Air Act mandates technician certification for HVACR equipment servicing.
Certified technicians required to prevent harmful refrigerant release during maintenance.

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Description

This quiz covers essential terms and concepts related to refrigerants, particularly focusing on the Montreal Protocol and its impact on CFC production. Test your knowledge on the regulations that aim to protect the ozone layer and the timeline of these environmental agreements.