Core Flashcards
Stratospheric ozone
Protective shield, ozone protects from ultraviolet radiation from the sun
ODP
Ozone depletion potential measures the ability of a substance to destroy ozone in the stratosphere
What negative effects result from ozone depletion?
Increased rates of skin cancer, cataracts and negative effects on the environment, resulting in decreased crop yields and damage to marine organisms 
What is ozone made up of?
Three oxygen atoms
How is an ozone molecule affected by chlorine?
The chlorine takes one of the ozone’s three atoms forming a compound, called chlorine monoxide (CIO). CIO collides with another ozone molecule, releasing its oxygen atom.
A single chlorine atom can last in the stratosphere for _____ years and destroy up to ______ozone molecules
120 years destroying 100,000 ozone molecules
Does the chlorine in CFCs and HCFCs breakdown into compounds that dissolve in water or rain out of the atmosphere?
NO
GWP
Global warming potential. Established to provide comparisons of the global warming impacts of different gases over a span of time.
What is used as a baseline measurement for global warming potential with a value of 1?
Carbon dioxide
Which refrigerants have the lowest global warming potential?
Hydrocarbon (HC) and Hydrofluoroolefin (HFO)
HFCs have a _______ global warming potential, making them damaging to the environment
Very high
CFC
Chlorofluorocarbon. Highest ozone depletion potential. Examples: R-11 and R12
HCFC
Hydrochlorofluorocarbon. Contains hydrogen, chlorine, fluorine, and carbon. The hydrogen makes them less harmful to stratospheric ozone
HFC
Hydrofluorocarbon. Contain hydrogen, fluorine, and carbon atoms connected by single bonds. Lowest/no ozone depletion potential, but do have an effect on global warming
HFO
Hydrofluoroolefin. Contain hydrogen, fluorine, and carbon atoms connected with at least one double bond between the carbon atoms. No ozone depletion potential, but do you have a very small effect on global warming
HC
Hydrocarbon. Elementary compound of hydrogen and carbon. Although flammable, they post the least amount of danger to the environment considered natural refrigerants.
Can propane cylinders for grilling be used as refrigerant?
No. They contain impurities that can damage refrigerant equipment. 
Azeotropic
Refrigerant mixtures containing two or more refrigerant. Acts like a single or pure compound refrigerant
Zeotropic
Mixtures of components that have different boiling points. Blend the refrigerant associated with temperature glide.
Bubble point (liquid)
Values used when charging by condenser sub cooling
Dew Point (vapor)
Values used for charging by suction or evaporator superheat
How should zeotropic or near azeotropic blends of refrigerants be charged into the system?
By liquid
Fractionization
Refrigerant leaking at uneven rates due to different vapor pressures
What EPA approved refrigerant can be used as direct drop in replacements to service an R 22 or any other system?
The EPA does not approve any substitute refrigerants as direct drop in replacements
When retrofitting or converting a system to use a different refrigerant only ______ substitutes can be used.
EPA-approved
Low Pressure refrigerant
30 psig or lower at 104 degrees liquid phase. Example: R11, R123
Medium Pressure refrigerants
Between 30 psig and 155 psig at 104 degrees liquid phase. Examples: R12, R134, R1234YF
High Pressure refrigerants
Between 155 psig and 340 psig at 104 degrees liquid phase. Examples: R22, R410, R717
Very High pressure refrigerants
Over 340 psig at 104 degrees liquid phase. Example: R744 CO2
What type of oil does HCFC refrigerant blends use?
Synthetic alkylbenzene
What type of oil does HFC refrigerants use?
Esther based oils; they are hydroscopic and absorb moisture
Montreal Protocol
An international treaty, that addresses, ozone, depleting substances and their alternatives
As of 2017, a technician can be fined $_________ a per violation for violating the Clean Air Act.
$44,539
In what year is the phase out for the production and imports of newly manufactured R22 and HCFC142 in the US?
2020
And what year will all HCFC refrigerants be phased out?
2030
Reclaimed, refrigerant must meet what AHRI standard?
AHRI standard 700
Technicians can only charge used CFC, HCC, or HFC refrigerants back into the ______appliance or another appliance belonging to the _______owner.
Same owner. Used refrigerant unless reclaimed cannot change ownership.
Recovery equipment must be tested according to a AHRI standard _____?
AHRI 740
When disposing of appliances with 50 to 50 pounds of refrigerant, what must records include?
-type of refrigerant
-quantity of refrigerant, by type
-Quantity recovered from dispose of appliances in each calendar month
-Quantity of refrigerant, by type, sent for reclamation or destruction
What type of refrigerant can be vented and does not require 608 certification?
Carbon Dioxide R744
Can you top off a refrigerant system with another type of refrigerant?
No. This can void equipment warranty, ruin the refrigerant, damage, the equipment, and cause personal injury, or death.
Recover
To remove refrigerant in any condition from the system and store it in an approved recovery cylinder container
Recycle
To extract, refrigerant from an appliance and clean the refrigerant for use in equipment of the same owner without meeting the requirements for reclamation
Recycling equipment must meet what AHRI standard?
AHRI 740
Reclaim
To process refrigerant to a level equal to new “virgin” product. Must meet AHRI 700 standards
System dependent (passive) recovery
Capture refrigerant with the assistance of components in the appliance from which refrigerant is being recovered (compressor etc)
Self-contained (active) recovery
Has its own means to draw refrigerant out of the appliance. Example: recovery machine
Low ambient temperatures or long hoses between the unit and recovery machine _________ recovery time
Increase
What type of hoses should be used for the recovery of refrigerant?
Short as possible and large diameter hoses
How should newly install systems be checked for leaks?
System should be pressurized with dry nitrogen for leak detection purposes. If any electronic leak detector is to be used, a trace refrigerant can be added along with dry nitrogen. Soap bubbles can pinpoint the leak.
Evacuate to ______ microns
500 or lower
Dehydration
Purpose is to remove water and water vapor from the system. Moisture and the system can cause hydrochloric and hydrofluoric acids to form.
For accurate readings during system evacuation, vacuum gauge should be connected where in relation to the pump?
As far away from the vacuum pump as possible. Measuring final system, vacuum should be done with system, isolated and pump off.
When pressurizing the system with nitrogen, you should always charge through a _________?
Pressure regulator and relief valve downstream from the regulator. If using multiple relief valves, they should be installed in parallel to each other.
Recovery cylinders should be filled to no more than _____% of its capacity by weight 
80%
A reusable container for refrigerant that is under high-pressure (above 15psig) must be hydrostatically tested every _____ years?
5 years
Recovery tanks have ______bodies and ______tops
Grey bodies and yellow tops
