2
Unit 3 Refrigeration and Refrigerants Review Questions with
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precise detailed answers || ||
Name three reasons why ice melts in an icebox - ✔✔It absorbed heat, boxes made of wood
|| || || || || || || || || || || || || || || ||
then metal, boxes insulated with cork.
|| || || || || ||
What are the approximate temperature ranges for low-, medium-, and high-temperature
|| || || || || || || || || || ||
refrigeration applications? - ✔✔Low - below 0 degree to -10 degree
|| || || || || || || || || ||
medium - 35 degree to 45 degree || || || || || ||
high - above 45 degree and below room temperature
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One ton of refrigeration is
|| || || ||
A. 1200 Btu.
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B. 12,000 Btu/h.
|| ||
C. 120,000 Btu.
|| ||
D. 120,000 Btu/h. - ✔✔B. 12,000 Btu
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Describe briefly the basic refrigeration cycle. - ✔✔It is the process of removing heat from a
|| || || || || || || || || || || || || || || ||
place where it is not wanted and transferring that heat to a place where it makes little or
|| || || || || || || || || || || || || || || || || ||
no difference.
||
What is the relationship between pressure and the boiling point of liquids? - ✔✔The
|| || || || || || || || || || || || || ||
temperature / pressure relationship correlates the vapor pressure and the boiling point of
|| || || || || || || || || || || || ||
water and is basis for controlling a systems temperature.
|| || || || || || || ||
What is the function of the evaporator in a refrigeration or air-conditioning system? - ✔✔It
|| || || || || || || || || || || || || || ||
is like a heat sponge. It absorbs heat into the system.
|| || || || || || || || || ||
, 2
What does the comperessor do in the refrigeration system? - ✔✔It is the heart of the
|| || || || || || || || || || || || || || || ||
refrigeration system. It pumps heat through the system in the form of heat-laden
|| || || || || || || || || || || || ||
refrigerant. It is also called vapor pump. || || || || || ||
Define a superheated vapor - ✔✔the temperature of vapor refrigerant above its saturation
|| || || || || || || || || || || || ||
( change - of - state ) temperature.
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The evaporating pressure is 76 psig for R-22 and the evaporator outlet temperature is 58*F.
|| || || || || || || || || || || || || || ||
What is the evaporator superheat for this system?
|| || || || || || || ||
A. 13*F ||
B. 74*F ||
C. 18*F ||
D. 17*F - ✔✔A. 13*F
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If the evaporating pressure was 76 psig for R-22 and the compressor inlet temperature was
|| || || || || || || || || || || || || || ||
65*F, whatwould be the total superheat entering the compressor?
|| || || || || || || ||
A. 11*F ||
B. 21*F ||
C. 10*F ||
D. 20*F - ✔✔D. 20*F
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Define the term subcooled liquid - ✔✔The temperature of a liquid when it is cooled below
|| || || || || || || || || || || || || || || ||
its condensing temperature.
|| ||
The condensing pressure is 260 psig and the condenser outlet temperature is 108*F for R-
|| || || || || || || || || || || || || ||
22. By how many degrees is the liquid subcooled in the condenser?
|| || || || || || || || || || || ||
A.12*F
B. 42*F ||
Unit 3 Refrigeration and Refrigerants Review Questions with
|| || || || || || || ||
precise detailed answers || ||
Name three reasons why ice melts in an icebox - ✔✔It absorbed heat, boxes made of wood
|| || || || || || || || || || || || || || || ||
then metal, boxes insulated with cork.
|| || || || || ||
What are the approximate temperature ranges for low-, medium-, and high-temperature
|| || || || || || || || || || ||
refrigeration applications? - ✔✔Low - below 0 degree to -10 degree
|| || || || || || || || || ||
medium - 35 degree to 45 degree || || || || || ||
high - above 45 degree and below room temperature
|| || || || || || || ||
One ton of refrigeration is
|| || || ||
A. 1200 Btu.
|| ||
B. 12,000 Btu/h.
|| ||
C. 120,000 Btu.
|| ||
D. 120,000 Btu/h. - ✔✔B. 12,000 Btu
|| || || || || ||
Describe briefly the basic refrigeration cycle. - ✔✔It is the process of removing heat from a
|| || || || || || || || || || || || || || || ||
place where it is not wanted and transferring that heat to a place where it makes little or
|| || || || || || || || || || || || || || || || || ||
no difference.
||
What is the relationship between pressure and the boiling point of liquids? - ✔✔The
|| || || || || || || || || || || || || ||
temperature / pressure relationship correlates the vapor pressure and the boiling point of
|| || || || || || || || || || || || ||
water and is basis for controlling a systems temperature.
|| || || || || || || ||
What is the function of the evaporator in a refrigeration or air-conditioning system? - ✔✔It
|| || || || || || || || || || || || || || ||
is like a heat sponge. It absorbs heat into the system.
|| || || || || || || || || ||
, 2
What does the comperessor do in the refrigeration system? - ✔✔It is the heart of the
|| || || || || || || || || || || || || || || ||
refrigeration system. It pumps heat through the system in the form of heat-laden
|| || || || || || || || || || || || ||
refrigerant. It is also called vapor pump. || || || || || ||
Define a superheated vapor - ✔✔the temperature of vapor refrigerant above its saturation
|| || || || || || || || || || || || ||
( change - of - state ) temperature.
|| || || || || || ||
The evaporating pressure is 76 psig for R-22 and the evaporator outlet temperature is 58*F.
|| || || || || || || || || || || || || || ||
What is the evaporator superheat for this system?
|| || || || || || || ||
A. 13*F ||
B. 74*F ||
C. 18*F ||
D. 17*F - ✔✔A. 13*F
|| || || ||
If the evaporating pressure was 76 psig for R-22 and the compressor inlet temperature was
|| || || || || || || || || || || || || || ||
65*F, whatwould be the total superheat entering the compressor?
|| || || || || || || ||
A. 11*F ||
B. 21*F ||
C. 10*F ||
D. 20*F - ✔✔D. 20*F
|| || || ||
Define the term subcooled liquid - ✔✔The temperature of a liquid when it is cooled below
|| || || || || || || || || || || || || || || ||
its condensing temperature.
|| ||
The condensing pressure is 260 psig and the condenser outlet temperature is 108*F for R-
|| || || || || || || || || || || || || ||
22. By how many degrees is the liquid subcooled in the condenser?
|| || || || || || || || || || || ||
A.12*F
B. 42*F ||
