Refrigeration and Air Conditioning Exam

Refrigerants and Ozone Depletion

• CFCs, HCFCs, and HFCs contribute to global warming.
• CFCs will no longer be manufactured or imported into the United States after 1995.

Refrigerant Types and Components

• HFC refrigerants contain hydrogen, fluorine, and carbon.
• HCFC refrigerants contain hydrogen, chlorine, fluorine, and carbon.
• CFCs contain chlorine, fluorine, and carbon.
• HFCs are less harmful to stratospheric ozone than CFCs.
• Refrigerants containing Bromine are the most harmful to stratospheric ozone.

Refrigerant Recovery and Handling

• The recovery of refrigerants is necessary to maintain adequate supplies for service calls, prevent venting to the atmosphere, and prevent stratospheric ozone depletion.
• Recovery equipment that relies on the pressure of the refrigerant in the appliance is considered system-dependent.
• Recovery equipment that relies on the compressor in the system is also considered system-dependent.
• "Self-contained" recovery devices can capture liquid and/or vapor refrigerant without assistance from components in the air-conditioning or refrigeration equipment.
• A cylinder with a gray body and a yellow top is designed to hold recovered refrigerant.
• Refillable refrigerant cylinders must never be filled to more than 80% of their capacity by weight.

Safety and Equipment

• PPE (gloves, safety glasses, safety shoes, etc.) should always be worn when handling and filling refrigerant cylinders.
• Refrigerant vapors or mist should not be inhaled because they may cause heart irregularities and/or unconsciousness.
• An oil sample should be taken for reasons such as the system having a leak or a major component failure.
• Use an alcohol spray to remove ice from a sight glass.
• A compound pressure gauge, typically used on the low side of the system, measures pressure in psig and inches of mercury.

Environmental Regulations

• Violations of the Clean Air Act include falsifying or failing to keep required records, failing to reach required evacuation levels, and knowingly releasing CFC or HCFC refrigerants or their substitutes.
• State and local governments can make laws that follow the Clean Air Act/EPA regulations or contain stricter regulations.
• The EPA requires the installation of a service aperture or process stub on all appliances using a class I or class II substance as a refrigerant.

Ozone Depletion

• Ozone depletion in the stratosphere is a global problem.
• Ozone in the stratosphere above the earth consists of molecules of 3 oxygen atoms.
• Chlorine monoxide is a chemical found in the upper stratosphere, indicating that the ozone layer is being destroyed.

Miscellaneous

• Technicians receiving a passing grade on the Type II (medium-pressure, high-pressure, and very high-pressure) exam are certified to recover refrigerant during maintenance, service, or repair of medium- and high-pressure equipment.
• Ester-based oils can be mixed with no other oils.
• The synthetic lubricant presently used with ternary blends containing HCFCs is alkylbenzene.
• If a system will not hold vacuum after it has been evacuated, it may be leaking.
• The size of the equipment being evacuated, the ambient temperature, and the amount of moisture in the system affect the speed of evacuation.

This quiz covers questions related to refrigeration and air conditioning, including types of refrigerants, oils used, and technician certifications.