HVAC Air Condition Esco 2022
✅✅
Heat which causes a change in temperature of a substance is called -
-Sensible Heat
Heat added to a substance without a rise in temperature is called - ✅✅-Latent
Heat
✅✅
Heat added to refrigerant in a vapor state after the evaporation process is called -
-Superheat
A scroll compressor moved refrigerant by means of - ✅✅-Involute spirals
The movement of heat by way of fluid is called - ✅✅-Convection
The movement of heat through a solid object is called - ✅✅-Conduction
The standard unit for measuring the quantity of heat in a substance - ✅✅-British
Thermal Unit
A refrigerant gives up heat when it - ✅✅-Condenses
✅✅
Why must refrigerant in the suction line be slightly warmer than the saturation
temperature? - -Prevent liquid slugging of compressor
✅✅
It is desirable for refrigerant in the suction line to be slightly superheated in order to -
-Insure liquid refrigerant does not enter the compressor
A mechanical shaft seal is necessary on - ✅✅-Semi-hermetic compressor
✅✅-Liquid refrigerant in the compressor clearance space
Liquid slugging is -
The clearance space in a reciprocating compressor - ✅✅-Varies depending on
compressor speed
✅✅
Which of the following types of air conditioning compressors is most energy efficient
- -Centrifugal
✅✅
Which of the following represent the right order for the functions of a condenser? -
-De-superheat, condenses, sub-cools
Refrigerant R-134a vapor enters the compressor at 124 psig, 100°f. It leaves as a
✅✅
liquid from the condenser sub-cooled 20°f, and the pressure will approximately -
-18.4 psig
, ✅✅
There are 3 basic types of condensers, the air cooled, the water cooled, and the
_______ cooled - -Evaporative
10 lbs. of refrigerant passing through a water cooled condenser will lose 20 BTU's of
heat per lb. If 10 lbs. of water passes through the condenser with an entering
✅✅
temperature of 80°f. The temperature of the water leaving the condenser is -
-100°f
The heat removed from the refrigerant by the condenser is - ✅✅-Both sensible and
latent heat
An energy recovery ventilator is - ✅✅-An air to air heat exchanger to recover heat
✅✅
Which of the following can NOT be used as a low ambient temperature control? -
-Crankcase regulating valves
The state of refrigeration in the suction line should be - ✅✅-Low pressure/ low
temperature vapor
The state of refrigerant entering the condenser is - ✅✅-High pressure/ highly
superheated vapor
The evaporator - ✅✅-Transfers heat from the refrigerated space to the refrigerant
✅✅
Which of the following is not a thermodynamic property of refrigerant -
-Flammability
✅✅
The sequential order of steps in the vapor-compression process are -
-Compression, condensation, expansion, vaporization
✅✅
If a 30 pound container of R-410A refrigerant has been stored over night at 70°F, the
pressure in the cylinder should be approximately - -201 psig
Fan airflow pressures are usually measured in - ✅✅-Inches of water column (WC)
Zero psig is - ✅✅-The same as atmospheric pressure
The temperature at which moisture will start to condense from the air is - ✅✅-Dew
point temperature
A compound pressure gauge measures - ✅✅-Pressure and vacuum
✅✅
Heat which causes a change in temperature of a substance is called -
-Sensible Heat
Heat added to a substance without a rise in temperature is called - ✅✅-Latent
Heat
✅✅
Heat added to refrigerant in a vapor state after the evaporation process is called -
-Superheat
A scroll compressor moved refrigerant by means of - ✅✅-Involute spirals
The movement of heat by way of fluid is called - ✅✅-Convection
The movement of heat through a solid object is called - ✅✅-Conduction
The standard unit for measuring the quantity of heat in a substance - ✅✅-British
Thermal Unit
A refrigerant gives up heat when it - ✅✅-Condenses
✅✅
Why must refrigerant in the suction line be slightly warmer than the saturation
temperature? - -Prevent liquid slugging of compressor
✅✅
It is desirable for refrigerant in the suction line to be slightly superheated in order to -
-Insure liquid refrigerant does not enter the compressor
A mechanical shaft seal is necessary on - ✅✅-Semi-hermetic compressor
✅✅-Liquid refrigerant in the compressor clearance space
Liquid slugging is -
The clearance space in a reciprocating compressor - ✅✅-Varies depending on
compressor speed
✅✅
Which of the following types of air conditioning compressors is most energy efficient
- -Centrifugal
✅✅
Which of the following represent the right order for the functions of a condenser? -
-De-superheat, condenses, sub-cools
Refrigerant R-134a vapor enters the compressor at 124 psig, 100°f. It leaves as a
✅✅
liquid from the condenser sub-cooled 20°f, and the pressure will approximately -
-18.4 psig
, ✅✅
There are 3 basic types of condensers, the air cooled, the water cooled, and the
_______ cooled - -Evaporative
10 lbs. of refrigerant passing through a water cooled condenser will lose 20 BTU's of
heat per lb. If 10 lbs. of water passes through the condenser with an entering
✅✅
temperature of 80°f. The temperature of the water leaving the condenser is -
-100°f
The heat removed from the refrigerant by the condenser is - ✅✅-Both sensible and
latent heat
An energy recovery ventilator is - ✅✅-An air to air heat exchanger to recover heat
✅✅
Which of the following can NOT be used as a low ambient temperature control? -
-Crankcase regulating valves
The state of refrigeration in the suction line should be - ✅✅-Low pressure/ low
temperature vapor
The state of refrigerant entering the condenser is - ✅✅-High pressure/ highly
superheated vapor
The evaporator - ✅✅-Transfers heat from the refrigerated space to the refrigerant
✅✅
Which of the following is not a thermodynamic property of refrigerant -
-Flammability
✅✅
The sequential order of steps in the vapor-compression process are -
-Compression, condensation, expansion, vaporization
✅✅
If a 30 pound container of R-410A refrigerant has been stored over night at 70°F, the
pressure in the cylinder should be approximately - -201 psig
Fan airflow pressures are usually measured in - ✅✅-Inches of water column (WC)
Zero psig is - ✅✅-The same as atmospheric pressure
The temperature at which moisture will start to condense from the air is - ✅✅-Dew
point temperature
A compound pressure gauge measures - ✅✅-Pressure and vacuum
