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HVAC Universal Certification Exam Study
Guide.
Azeotrope - answer✔a blend of 2 or more components whose equilibrium vapor phase and liquid
phase compositions are the same given pressure.
Halocarbon - answer✔a holgenated hydrocarbon containing one or more of the 3 halogens:
fluorine, chlorine, and bromine.
CFCs consist of __, __, and __. - answer✔Chlorine, fluorine, and carbon
CFCs are chemically very stable because they contain no __. - answer✔Hydrogen
CFCs are damaging the _ ozone layer. - answer✔Stratospheric
Of the 3 common types of refrigerants _ has the highest high ODP. - answer✔CFCs
_ test methods are assumed by the EPA as the most effective methods for locating small leaks. -
answer✔Electronic and ultrasonic
After evacuation of a system, if the pressure rises above ambient pressure, then _. -
answer✔trapped refrigerant is boiling off.
In cases where the refrigerant can't be reclaimed due to contamination with other refrigerants, the
refrigerant _. - answer✔must be destroyed by incineration at an approved facitily
The system vacuum gauge should be connected _. - answer✔as close as possible to the system
being evacuated
Manufacture of CFCs will be banned after December 31, _. - answer✔1995
A second catagory of refrigerants currently available is the HCFCs. They contain no chlorine but
they contain _, which makes them chemically less stable ones they enter the atmosphere. -
answer✔hydrogen
Under EPA regulations, reclaimed refrigerant must meet _ standards for purity. - answer✔ARI-
700
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10/21/2024 9:24 PM
_ recovery devices are so named because they depend on components of the air conditioning
system they are emptying. - answer✔System-dependent
All devices used for refrigerant recovery must meet _ standards. - answer✔EPA
HCFCs - answer✔22, 23, 123, 124, 141b, 142b, 225ca, 225cb, 401A, 401B, 402A, 402B.
Refrigerants which contain no chlorine at all are called _. - answer✔HFCs
CHF2CF3 refrigerant is a _. - answer✔HFC
Ozone in the stratosphere consists of molecules containing _ oxygen atoms. - answer✔3
_ in refrigerants causes ozone depletion - answer✔Chlorine
CFCs are able to reach the stratosphere because _. - answer✔they are chemically very stable
The lower case letter following the refrigerant number is the _. - answer✔form of the isomer
_ refrigerants are higher toxicity. - answer✔Class B
_ refrigerants don't show flame propagation when tested in air at 21 degrees C and 101 kPa. -
answer✔Class 1
_ refrigerants are flammable and have lower toxicity. - answer✔A3
R-134a tanks are _. - answer✔light blue
Disposable cylinders are manufactured to specifications established by the _. - answer✔DOT
Every refrigerant cylinder is equipped with a _ device that will automatically vent pressure
before it reaches the rupture point. - answer✔safety (pressure) relief valve
Refillable cylinders are regulated in their design, fabrication and testing by the _ for use in the
transportation of refrigerants - answer✔DOT
Capturing and ultimately eliminating the use of CFCs is being done in the US to stop damage to
the _ ozone layer - answer✔stratospheric
State and local governments may establish laws that contain _ regulations than Clean Air
Act/EPA regulations. - answer✔stricter
The Clean Air Act _. - answer✔calls the phase out of CFCs and HCFCs, prohibits venting,
requires the EPA to set standards for equipment and techs