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30 Cards in this Set
- Front
- Back
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air conditioning is
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controling of temp, humidity, cleanness of the air, and distribution of the air.
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what are the three ways the body cools itself
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convection,evaperation,radiation
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the air filter is found at
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the air return duct
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list the six common types of metering devices
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hand operated, low/high side float,axv,txv,capullary tube
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subcooling is
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removale of heat from a liquid to a temp below it's saturation temp
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net refrigerant effect is
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the amount of BTU's a refrigerant can absorb into a system.
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superheat is
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after all liquid is turned into vapor the heat added to it after that.
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THe Enthalpy of a refrigerant is expressed in
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BTU's per lb
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de-superheating
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BTU's removed from a superheated vapor back to it saturation state
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the specific heat value nof ice is
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.5 BTU's
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pressure is
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force per unit area
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three of the main types of compressors are
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Reciprocating,rotary, centrifugal
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compressor valves are operated by
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pressure differance
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which value is designed to operate below the valve plate?
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suction
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what compressor designed uses an external moto?
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open type
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the four types of shaft seal used on a open type compressor
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packing gland, stationary bellows, diaphragm,rotary
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most reciprocating compressors use what type of piston drive
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Eccentric or crank
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___ ____ refers to the space between the top of the piston and the bottom of the valve plate at the top of the piston stroke
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clearance volume
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the clearance volume should be kept to a .
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minium
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during operation liquid refrigerant in the compressor clearance space is known as
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liquid slugging
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what type of drier desiccant is designed to hold moisture by sponge action
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adsorbent
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Which condenser type is considered the most efficient
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evaporative cooled
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the two most widely used water cooled condenser designs are
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horizontal shell in tube, shell and coil.
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what are the two types of evaporators
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direct expansion; flooded
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secondary refrigerant is normally
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water or brine
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the evaporative type coil used with chiller systems designed to absorb heat into a a secondary refrigerant are commonly called
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convector coil
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how is refrigerant flow controlled in cap tubes?
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pressure differance.
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the high side float metering device is controlled by
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rate of condensation
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what pressure causes the txv to open wider?
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bulb only
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to increase the txv superheat setting the spring pressure must be _________.
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increased
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