CIRO Chapter 6 questions with 100%
complete solutions
Which of the following factors listed below does not affect heat transfer
A. Temperature difference
B. Surface area
C. Thermal conductivity
D. Enthalpy - correct answer ✔✔1
An example of a poor conductor of heat is
A. Aluminum tubing
B. Schedule 40 steel pipe
C. Plastic
D. Water - correct answer ✔✔1
Thermal conductivity ('k') is
A. Exactly the same value for any metal
B. The number of BTUs that will pass in one hour through a material 1" thick with an area of 1 ft2 if the
temperature difference from one side to the other is 1deg F
C. A measure of the total energy (heat content) per pound of refrigerant measured in BTU's
D. A relationship between heat and temperature that is useful in determining discharge temperatures. It
is the heat moved into or out of the process, divided by the absolute temperature in BTUs/lb./R - correct
answer ✔✔1
Which is not common source of fouling of a heat exchange surface
A. Water
B. Oil
C. Ice
, D. Dirt - correct answer ✔✔1
Reducing the evaporating temperature of an air unit evaporator causes
A. Reduced humidity in the room and lower operating costs
B. Increased humidity in the room and lower operating costs
C. Reduced humidity in the room and higher operating cost
D. No changes - correct answer ✔✔1
Which statement is true?
A. The higher the 'k' factor the greater the thermal conductivity
B. The lower the 'k' factor the greater the thermal conductivity
C. The higher the 'k' factor the lower the thermal conductivity
D. The 'k' factor is not associated with thermal conductivity - correct answer ✔✔1
Optimum 'k' factor for the given material that the heat exchanger is made of results when
A. There is no impeding substance such as ice, dirt or oil on the surfaces of the heat exchanger tubes
B. Maximum airflow across the coil is achieved
C. The system is operating with the design recirculation ratio
D. The system is maintaining temperature - correct answer ✔✔1
When air flow is decreased across a heat exchange surface, cooling capacity is
A. Reduced
B. Increased
C. Not changed because area is not changed
D. Not changed because coil temperature is not changed - correct answer ✔✔1
Centrifugal fans have an advantage over propeller fans in that they _____________ than prop fans
A. Require less physical space
B. Consume more HP per cfm of air moved
complete solutions
Which of the following factors listed below does not affect heat transfer
A. Temperature difference
B. Surface area
C. Thermal conductivity
D. Enthalpy - correct answer ✔✔1
An example of a poor conductor of heat is
A. Aluminum tubing
B. Schedule 40 steel pipe
C. Plastic
D. Water - correct answer ✔✔1
Thermal conductivity ('k') is
A. Exactly the same value for any metal
B. The number of BTUs that will pass in one hour through a material 1" thick with an area of 1 ft2 if the
temperature difference from one side to the other is 1deg F
C. A measure of the total energy (heat content) per pound of refrigerant measured in BTU's
D. A relationship between heat and temperature that is useful in determining discharge temperatures. It
is the heat moved into or out of the process, divided by the absolute temperature in BTUs/lb./R - correct
answer ✔✔1
Which is not common source of fouling of a heat exchange surface
A. Water
B. Oil
C. Ice
, D. Dirt - correct answer ✔✔1
Reducing the evaporating temperature of an air unit evaporator causes
A. Reduced humidity in the room and lower operating costs
B. Increased humidity in the room and lower operating costs
C. Reduced humidity in the room and higher operating cost
D. No changes - correct answer ✔✔1
Which statement is true?
A. The higher the 'k' factor the greater the thermal conductivity
B. The lower the 'k' factor the greater the thermal conductivity
C. The higher the 'k' factor the lower the thermal conductivity
D. The 'k' factor is not associated with thermal conductivity - correct answer ✔✔1
Optimum 'k' factor for the given material that the heat exchanger is made of results when
A. There is no impeding substance such as ice, dirt or oil on the surfaces of the heat exchanger tubes
B. Maximum airflow across the coil is achieved
C. The system is operating with the design recirculation ratio
D. The system is maintaining temperature - correct answer ✔✔1
When air flow is decreased across a heat exchange surface, cooling capacity is
A. Reduced
B. Increased
C. Not changed because area is not changed
D. Not changed because coil temperature is not changed - correct answer ✔✔1
Centrifugal fans have an advantage over propeller fans in that they _____________ than prop fans
A. Require less physical space
B. Consume more HP per cfm of air moved
