ESCO A/C Exam Questions And
Answers
heat which causes a change in temperature of a substance is called - ANS sensible heat
Heat added to a substance without a rise in temperature - ANS latent heat of vaporization
Heat added to the refrigerant in a vapor state after the evaporation process is called - ANS
superheat
scroll compressor move refrigerant by - ANS involute spirals
the movement of heat by way of fluid is called - ANS convection
the movement of heat by direct contact is - ANS conduction
the standard unit for measuring the quantity of heat in a substance is - ANS btu
refrigerant gives up heat when - ANS it condenses
why must refrigerant in the suction line be slightly warmer than the saturation temperature? -
ANS prevent liquid slugging of the compressor
the state of the refrigerant in the suction line should be - ANS low pressure / low
temperature vapor
the state of the refrigerant entering the condenser is - ANS high pressure / highly
superheated vaoor
the evaporator - ANS Transfers heat from the refrigerated space to the refrigerant
which of the following is not a thermodynamic property of refrigerants - ANS flammability
The sequential order of steps in the vapor compressions process are - ANS compression,
condensation, expansion, vaporization
if a 30 pound cylinder of reclaimed R 410 a refrigerant has been stored overnight at 70° the
pressure in the cylinder should be approximately - ANS 201 psig
, fan airflow pressures are usually measured in - ANS inches of water column
0 pounds per square inch absolute is - ANS A pressure which cannot be further reduced
0 pounds per square inch gauge is - ANS The same as atmospheric pressure
The temperature at which moisture will start to condense from the air is called - ANS
Dewpoint temperature
compound pressure gauge measures - ANS pressure and vacuum
mechanical shaft seal is necessary on a - ANS Open Drive compressor
liquid slugging is - ANS liquid refrigerant in the compressor clearance space
The clearance space in reciprocating compressor - ANS has an effect on compressor
capacity
which of the following types of air conditioning compressor is is most energy efficient - ANS
scroll
Which of the following represent the right order for the functions of a condenser - ANS de
superheat, condenses, sub cools
refrigerant R 134a vapor enters the condenser at 124 psi G, 100°F. it leaves as liquid liquid from
the condenser subcooled 20°F and the pressure will be approximately - ANS 87 psig
there are three basic types of condensers, the air cooled, the water cooled and the - ANS
evaporative cooled
10 pounds of refrigerant passing through a water cooled condenser will lose 20 BTUs of heat
per pound. If 10 pounds of water passes through the condenser with an entering temperature of
80°F the temperature of the water leaving the condenser is - ANS 100 degrees F
The heat removed from the refrigerant by the condenser is - ANS Both sensible and latent
heat.
an energy recovery ventilator is - ANS an air to air heat exchanger to recover heat
when testing the efficiency of an air cooled condenser, the refrigerant condensing temperature
should be approximately ________ higher than the entering air temperature - ANS 30°F
Answers
heat which causes a change in temperature of a substance is called - ANS sensible heat
Heat added to a substance without a rise in temperature - ANS latent heat of vaporization
Heat added to the refrigerant in a vapor state after the evaporation process is called - ANS
superheat
scroll compressor move refrigerant by - ANS involute spirals
the movement of heat by way of fluid is called - ANS convection
the movement of heat by direct contact is - ANS conduction
the standard unit for measuring the quantity of heat in a substance is - ANS btu
refrigerant gives up heat when - ANS it condenses
why must refrigerant in the suction line be slightly warmer than the saturation temperature? -
ANS prevent liquid slugging of the compressor
the state of the refrigerant in the suction line should be - ANS low pressure / low
temperature vapor
the state of the refrigerant entering the condenser is - ANS high pressure / highly
superheated vaoor
the evaporator - ANS Transfers heat from the refrigerated space to the refrigerant
which of the following is not a thermodynamic property of refrigerants - ANS flammability
The sequential order of steps in the vapor compressions process are - ANS compression,
condensation, expansion, vaporization
if a 30 pound cylinder of reclaimed R 410 a refrigerant has been stored overnight at 70° the
pressure in the cylinder should be approximately - ANS 201 psig
, fan airflow pressures are usually measured in - ANS inches of water column
0 pounds per square inch absolute is - ANS A pressure which cannot be further reduced
0 pounds per square inch gauge is - ANS The same as atmospheric pressure
The temperature at which moisture will start to condense from the air is called - ANS
Dewpoint temperature
compound pressure gauge measures - ANS pressure and vacuum
mechanical shaft seal is necessary on a - ANS Open Drive compressor
liquid slugging is - ANS liquid refrigerant in the compressor clearance space
The clearance space in reciprocating compressor - ANS has an effect on compressor
capacity
which of the following types of air conditioning compressor is is most energy efficient - ANS
scroll
Which of the following represent the right order for the functions of a condenser - ANS de
superheat, condenses, sub cools
refrigerant R 134a vapor enters the condenser at 124 psi G, 100°F. it leaves as liquid liquid from
the condenser subcooled 20°F and the pressure will be approximately - ANS 87 psig
there are three basic types of condensers, the air cooled, the water cooled and the - ANS
evaporative cooled
10 pounds of refrigerant passing through a water cooled condenser will lose 20 BTUs of heat
per pound. If 10 pounds of water passes through the condenser with an entering temperature of
80°F the temperature of the water leaving the condenser is - ANS 100 degrees F
The heat removed from the refrigerant by the condenser is - ANS Both sensible and latent
heat.
an energy recovery ventilator is - ANS an air to air heat exchanger to recover heat
when testing the efficiency of an air cooled condenser, the refrigerant condensing temperature
should be approximately ________ higher than the entering air temperature - ANS 30°F
