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65 Cards in this Set
- Front
- Back
What year did the Montreal protocol take effect? |
1996 |
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What happened in 1996 |
Montreal Protocol |
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What is the Montreal protocol? |
International Agreement covering use of ozone depleting chemicals. |
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Define: Refridgerant |
Fluid that absorbs or gives off heat |
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Define: Latent Heat |
The amount of heat required to change the state of matter without changing its temperature. |
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Define: Sensible Heat |
Changes temperature of matter |
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What state is refrigerant in at atmospheric pressure? |
Usually a gas at atmospheric pressure |
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What happens to refrigerant during changing state? |
Will absorb or give off heat |
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What are two common refrigerants? |
Freon, Propane |
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Latent heat of fusion/freezing? |
Solids change to liquid / liquid changes to solid |
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Latent Heat of vaporization? |
Liquids changes to Vapour |
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Latent Heat of Condensation? |
Vapour changes to liquid |
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Latent heat of sublimation |
Solid changes directly to vapour. |
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Define: BTU |
The amount of heat required to raise the temperature of one pound of water one degree fahrenheit at sea level. |
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Name three methods of heat transfer. |
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How does conduction heat transfer work? |
Transfer between parts of a substance |
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How does Radiation heat transfer work? |
Transfer through a medium or vacuum by waves or electrons. |
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How does convection heat transfer work? |
Transfers by circulation due to temperature differences. |
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Does the Cold go to the Heat, or the Heat goes to the Cold? |
Heat goes to the Cold |
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What is a saturated liquid? |
Liquid at such a temperature that any added heat will change it to a vapour. |
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What is a Saturated Vapour? |
Vapour at such a temperature and pressure that with the removal of any heat it will condense. |
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What is Sub-Cooled Liquid? |
Liquid at a temperature below the saturation point. |
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What is Super-heated Vapour? |
Vapour that is above the saturation temperature. |
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What are the 10 Refrigeration Components? |
1. Compressor 2. Discharge Line 3. Condensor 4. Liquid Line 5. Metering Device 6. Expansion Valve 7. Evaporator 8. Suction Line 9. Low Side 10. High Side |
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What are the six forms of energy? |
Radiant Chemical Mechanical Electrical Nuclear Thermal |
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What two types of heat of concern in refrigeration systems? |
Sensible Heat and Latent Heat. |
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What is sensible heat? |
The Heat that will change the temperature, without causing a change in state. |
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What is Latent Heat? |
Heat that causes a change of state without a change in temperature. |
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How Many BTU's of heat will it take to change 1lb of 0°c Ice to 0°c water? |
144 BTU/HR |
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Latent Heat of freezing is? |
The amount of heat needed to be extracted to cause water to freeze. |
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Heat cannot be destroyed, it can only be transferred from one place to another. True or False? |
True
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List four types of refrigeration equipment |
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List four types of AC used in RV's |
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First Law of thermodynamics states? |
Energy Cannot be created or destroyed. |
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Second law of thermodynamics states? |
Heat always moves from hot to cold. |
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List Six forms of energy |
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Which energy causes matter to move? |
Mechanical Energy |
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Which energy is transferred through space? |
Radiant Energy |
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Which energy produces molecular motion? |
Heat Energy (Thermal) |
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Which energy consisting of electrons and protons? |
Electrical Energy |
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Which two types of heat are we concerned about with refrigeration systems? |
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Identify three methods of heat transfer? |
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Which type of heat is transferred by waves? |
Radiation |
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Which type of heat flows from one place to another by way of fluid or air? |
Convection |
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Substance that conduct heat poorly are called? |
Insulators |
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Liquid that is at such a temperature and pressure that if any amount of heat is added, some of the liquid will change to vapor is called? |
Saturated Liquid |
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The process of liquid changing to vapor is called? |
Evaporation |
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Vapour that is at such a temperature and pressure that, if any heat is removed some of the vapour will turn to liquid, is called? |
Saturated Vapour |
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The process of liquid changing to vapor is called? |
Evaporation |
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Refrigerant changes from liquid to low-pressure vapor at the? |
Evaporator |
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Refrigerant changes from a low-pressure vapor to a high-pressure vapor at the? |
Compressor |
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Refrigerant changes from a high-pressure vapor to a high-pressure liquid at the? |
Condenser Coil |
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In an air conditioner unit, the component in which the heat is absorbed from the living area is? |
Evaporator |
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In an air conditioner unit, the refrigerant forces heat to the _______ air in the _________ |
In an air conditioner unit, the refrigerant forces heat to the outside air in the condensor. |
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The main component of a heat pump that allows the heat pump to heat or cool is the? |
Reversing Valve |
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Refrigerants have been responsible for negative effects on the atmosphere known as? |
Ozone Layer Depletion |
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The proper operation of any RV Air conditioner system is highly dependent upon proper ______ and _______ of indoor and outdoor air circulation through the _________ |
The proper operation of any RV Air conditioner system is highly dependent upon proper volume and temperature of indoor and outdoor air circulation through the coils. |
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The reason A/C seem to quit cooling is ________ and _________ |
The reason A/C seem to quit cooling is Electrical Problems and Insufficient Evaporator Airflow |
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What is the medium being transferred in an air conditioning system? |
Heat |
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What is the Latent heat of vaporization for r22? |
90 BTU/LB |
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What is the ozone depletion ratio for r22? |
0.05 % |
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How would you check to see if a compressor is okay? |
Amp Draw & Ohmmeter |
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Is the start relay normally open or closed? |
Closed. |
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Could a compressor be faulty if all you measure was continuity? |
Yes |
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Should a compressor compress liquid? |
NO - Vapour Only. |