Thermodynacmics
Pressure
THE CYCLE
Refrigerant components
Service and Installation
100
This states that a temperature difference must be present for heat transfer to occur, and that the size of the difference will directly affect the rate of transfer.
What is the second law of thermodynamics
100
This is the atmospheric pressure at sea level.
What is 15
100
This is the component that lowers pressure is a refrigeration cycle.
What is the metering device
100
This must be replaced every time the system is opened and exposed to atmospheric air.
What is the filter dryer.
100
If there are non-condensables in a system, this will happen to the head pressure.
What is it will be high.
200
This type of heat transfer uses a medium. Typically air or water.
What is convection
200
To find absolute pressure you must add atmospheric pressure to this.
What is gauge pressure
200
the state of refrigerant as it leaves the compressor.
What is HPHT superheated vapor
200
This is located in the liquid line and stores excess refrigerant.
What is the receiver
200
An undercharged system will give the technician a superheat reading that is this.
What is higher
300
a substance that is heated above its boiling point is referred to as this.
What is superheated
300
This is the gauge that is able to read IN of HG.
What is the compound gauge
300
The two place in a refrigeration cycle that the refrigerant changes state.
What is the evaporator and condenser
300
This is when the service valves of an air conditioning system are open to the compressor.
What is backseated
300
Low airflow across the evaporator coil will show this kind of head pressure.
What is lower
400
Latent heat, or "hidden heat" changes this a substance.
What is the state
400
The compression ration of a compressor that has a discharge pressure of 250psig and a suction pressure of 85psig.
What is 2.6 to 1
400
This is an accessory in the refrigeration cycle that prevents liquid from entering the compressor.
What is the accumulator
400
This metering device lowers pressure based off of the length and diameter of its tubing.
What is a capillary tube
400
This is the process of storing the charge of a system in the condenser coil and compressor while repairs are made on other parts of the system.
What is a passive recovery
500
It takes this much heat to change one pound of water into vapor.
What is 970 btus
500
This is the measurement that is considered a "perfect" vacuum. (microns)
What is 500
500
This type of metering device adjusts how much it feeds the evaporator based off of the evaporators superheat.
What is TXV
500
This component is used to prevent refrigerant migration.
What is the crankcase heater
500
This is the process of removing all moisture in the system while lowering the pressure of the system below atmospheric pressure.
What is a vacuum
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