AMMONIA REFRIGERATION FINAL
EXAM CORRECT 100%
Convection is the transfer of ____ - ANSWER heat through a material or substance
Radiation is the ____ - ANSWER projection of heat like the heat radiated by the sun or
by an open flame
T or F: Heat is always on the move, traveling only in one direction and always from hot
to cold - ANSWER false
What are two methods of heat transfer? - ANSWER conduction and convection
What are two basic forms of refrigeration systems? - ANSWER direct expansion and
gravity flooded
T or F: Conduction is the heat transferred due to the temperature being different on one
side of a room than the other like the heat rising in a room - ANSWER true
T or F: A basic refrigeration system consists of an expansion device, an evaporator, a
compressor, and a condenser connected by a series of pipes - ANSWER true
T or F: Compression occurs as the ammonia refrigerant passes through the evaporator
- ANSWER false
T or F: The high side includes all components between the pressure reduction device
outlet to a point inside the compressor - ANSWER false
Heat contained in the area to be cooled and absorbed by the ammonia refrigerant as it
passes through the evaporator is called? - ANSWER the load
The low side of an ammonia refrigeration system consists of ... - ANSWER the
pressure reduction device and the condenser
T or F: Expansion occurs as the refrigerant flows through the compressor - ANSWER
false
T or F: When a hand expansion valve is opened, pressure behind the valve forces liquid
ammonia through a small opening causing a deliberate pressure drop to occur -
ANSWER false
T or F: Evaporation takes place as the ammonia refrigerant flows through the
compressor - ANSWER false
, T or F: The evaporation process is completed when the ammonia has passed through
the evaporator - ANSWER true
Absolute pressure is the pressure read by a gauge, plus the ____ atmospheric pressure
- ANSWER ambient
T or F: A pumped liquid, or re-circulation single stage system consists of a receiver, a
king valve, a pressure reduction device, an evaporator, a compressor, a condenser, a
vessel, a pump and an additional flow metering device - ANSWER true
Where is the worst place to have a leak in an ammonia refrigeration system? -
ANSWER high pressure liquid
How many BTUs does it take to convert 1 lb of saturated ammonia to 1 lb of saturated
gas? - ANSWER 561
How many BTUs does it take to convert 1 lb of liquid water at 212° to steam as 212°F -
ANSWER 970
How many BTUs does it take to melt 1 lb of ice into water at 32°F - ANSWER 144
What is specific heat ? - ANSWER the amount of heat transferred to change 1 lb of a
substance 1°F
What is the IDLH for ammonia? - ANSWER 300 PPM
Under what conditions may some synthetic refrigerants become toxic? - ANSWER
contact with an open flame
100°C equals - ANSWER 212°F
Copper tubing is never used with? - ANSWER R717
A "King" valve is a ____ - ANSWER receiver inlet valve
The centrifugal compressor is ____ a positive displacement compressor - ANSWER
not
Heat is rejected in the ____ - ANSWER condenser
What type of fan pushes air through coil? - ANSWER forced draft
How much current flow across the heart is necessary for it to be a fatal shock? -
ANSWER 0.1 ampere
EXAM CORRECT 100%
Convection is the transfer of ____ - ANSWER heat through a material or substance
Radiation is the ____ - ANSWER projection of heat like the heat radiated by the sun or
by an open flame
T or F: Heat is always on the move, traveling only in one direction and always from hot
to cold - ANSWER false
What are two methods of heat transfer? - ANSWER conduction and convection
What are two basic forms of refrigeration systems? - ANSWER direct expansion and
gravity flooded
T or F: Conduction is the heat transferred due to the temperature being different on one
side of a room than the other like the heat rising in a room - ANSWER true
T or F: A basic refrigeration system consists of an expansion device, an evaporator, a
compressor, and a condenser connected by a series of pipes - ANSWER true
T or F: Compression occurs as the ammonia refrigerant passes through the evaporator
- ANSWER false
T or F: The high side includes all components between the pressure reduction device
outlet to a point inside the compressor - ANSWER false
Heat contained in the area to be cooled and absorbed by the ammonia refrigerant as it
passes through the evaporator is called? - ANSWER the load
The low side of an ammonia refrigeration system consists of ... - ANSWER the
pressure reduction device and the condenser
T or F: Expansion occurs as the refrigerant flows through the compressor - ANSWER
false
T or F: When a hand expansion valve is opened, pressure behind the valve forces liquid
ammonia through a small opening causing a deliberate pressure drop to occur -
ANSWER false
T or F: Evaporation takes place as the ammonia refrigerant flows through the
compressor - ANSWER false
, T or F: The evaporation process is completed when the ammonia has passed through
the evaporator - ANSWER true
Absolute pressure is the pressure read by a gauge, plus the ____ atmospheric pressure
- ANSWER ambient
T or F: A pumped liquid, or re-circulation single stage system consists of a receiver, a
king valve, a pressure reduction device, an evaporator, a compressor, a condenser, a
vessel, a pump and an additional flow metering device - ANSWER true
Where is the worst place to have a leak in an ammonia refrigeration system? -
ANSWER high pressure liquid
How many BTUs does it take to convert 1 lb of saturated ammonia to 1 lb of saturated
gas? - ANSWER 561
How many BTUs does it take to convert 1 lb of liquid water at 212° to steam as 212°F -
ANSWER 970
How many BTUs does it take to melt 1 lb of ice into water at 32°F - ANSWER 144
What is specific heat ? - ANSWER the amount of heat transferred to change 1 lb of a
substance 1°F
What is the IDLH for ammonia? - ANSWER 300 PPM
Under what conditions may some synthetic refrigerants become toxic? - ANSWER
contact with an open flame
100°C equals - ANSWER 212°F
Copper tubing is never used with? - ANSWER R717
A "King" valve is a ____ - ANSWER receiver inlet valve
The centrifugal compressor is ____ a positive displacement compressor - ANSWER
not
Heat is rejected in the ____ - ANSWER condenser
What type of fan pushes air through coil? - ANSWER forced draft
How much current flow across the heart is necessary for it to be a fatal shock? -
ANSWER 0.1 ampere
