Questions with Verified Answers
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
What is the practical max compression ratio for a reciprocating compressor? - Answer-
8:1