Core Flashcards
What is the significance of an azeotropic mixture?
The mixture combines to act like a single-component refrigerant.
CFCs are more likely to reach the stratosphere than other chlorine-containing compounds because _____.
They are chemically stable.
1) They do not dissolve or breakdown in water.
2) They are heavier than air.
3) Typically NOT toxic
4) They do not decompose.
Chlorofluorocarbons, or CFCs, consist of which of the following chemicals?
Chlorine, fluorine, carbon
Which compounds are the most damaging of the ozone layer and have the highest ozone depletion potential rating?
CFCs
_________ tests methods are assumed by the EPA as the most effective methods for locating the general area of SMALL LEAKS.
Electronic and Ultrasonic
If a reclamation company is shipping a cylinder contains mixed refrigerants they may _________.
Agree to destroy the refrigerant but typically a substantial fee is charged.
One chlorine atom in the stratosphere is capable of destroying how many ozone molecules?
100,000 ozone molecules.
______ is s CFC.
R-502
R-141b & R-123 are HCFCs
R-134a is a HFC.
HCFC refrigerants cause ________ damage to the stratospheric ozone layer in comparison to CFC refrigerants.
Less
1) HCFCs contain hydrogen, making it chemically less stable than CFCs.
2) HCFCs decompose faster, causing very little to make it to the ozone layer.
The system vacuum gauge should be connected _______.
As far as possible from the vacuum pump.
1) This assists in getting the most accurate reading from the vacuum pump.
Manufacture of CFCs was banned as of December 31, ________.
1995
1) Supplies of CFC refrigerants for servicing and only come from recovery, recycling and reclamation.
Positive evidence that CFCs are in the stratosphere comes from _______.
Measurements of CFCs in air samples taken from the stratosphere
Under EPAs regulations, reclaimed refrigerant must meet _______ standards for purity before it can be resold.
ARI 700
_________ recovery devices are so named because they depend on components of the system. That is, they capture refrigerant with the assistance of components in the air conditioning or refrigeration equipment they are emptying.
System-dependent or passive-recovery devices
All devices used for refrigerant recovery must meet _____ standards.
EPA
List one HCFC refrigerant:
R-22
R-134a is a HFC
R-12 and R-113 are CFCs
Which refrigerant contain no chlorine?
HFCs
Which refrigerant is an HFC?
R-134a
R-123 & R-22 are HCFCs
R-11 is a CFC
Ozone in the stratosphere consists of molecules containing ______ oxygen atom(s).
3
________ in refrigerant causes ozone depletion.
Chlorine and Bromine
Recovery devices that can capture liquid and/or vapor refrigerant without the assistance of components in the air conditioning or refrigeration equipment are known as _______.
Self-contained or active recovery devices
Technicians are certified to recover refrigerant during the maintenance, service, or repair of packaged A/C or refrigeration equipment with five pounds or less of refrigerant if they receive a passing grade on ______ examinations.
Type I
Technicians are certified to recover refrigerant during the maintenance, service, or repair of high-pressure equipment if they receive a passing grade on ______ examinations.
Type II
High-pressure certification
Such as:
High-pressure CFC-12, HCFC-22, CFC-500, CFC-502, CFC-114
Very high-pressure CFC-13 & CFC-502
Technicians are certified to recover refrigerant during the maintenance, service, or repair of low-pressure equipment if they receive a passing grade on ______ examinations.
Type III
Low-pressure certification
Such as:
CFC-11, CFC-123
________ refrigerants leak at uneven rates due to the differences in the vapor pressures.
Blended
Non-azeotropic must be charged as a liquid.
