Which of the following statements about coil surfaces is false?

Which of the following statements about coil surfaces is false?

a) Air flows across the fins
b) Finned coils are more compact than smooth tube coils of the same capacity
c) Fins increase the contact surface area between the airstream and the tubes
d) All fins must be crimped
e) Finned coils are less expensive than smooth coils of the same capacity








Answer: D

Which one of the following methods is not a method of ensuring uniform steam distribution in steam coils?

Which one of the following methods is not a method of ensuring uniform steam distribution in steam coils?

a) installation of distributing plates within the steam header
b) "steam distributing" coils
c) installation of individual orifices into the supply end of each tube
d) once called "non-freeze coils"
e) controlling the face velocity of the air flowing over coils







Answer: E

Half serpentine water coil circuiting is used

Half serpentine water coil circuiting is used

a) in applications requiring high water velocities and low water pressure drops
b) where the water velocity in the tubes is more than 2.4 m/s
c) where the water velocity in the tubes is between 0.3 and 2.4 m/s
d) for any water velocity in the tubes
e) where the water velocity in the tubes is less than 0.3 m/s






Answer: E

Double serpentine water coil circuiting is used

Double serpentine water coil circuiting is used

a) where the water velocity in the tubes is less than 0.3 m/s
b) where the water velocity in the tubes is more than 2.4 m/s
c) for any water velocity in the tubes
d) where the water velocity in the tubes is between 0.3 and 2.4 m/s
e) in applications requiring low water velocities and low water pressure drops







Answer: B

Single serpentine water coil circuiting is used

Single serpentine water coil circuiting is used

a) where the water velocity in the tubes is less than 0.3 m/s
b) where the water velocity in the tubes is more than 2.4 m/s
c) for any water velocity in the tubes
d) where the water velocity in the tubes is between 0.3 and 2.4 m/s
e) in applications requiring high water velocities and low water pressure drops







Answer: D

Which of the following statements about water coils is false?

Which of the following statements about water coils is false?

a) Coils should be hooked up in a counterflow arrangement.
b) Coils need to be able to vent air.
c) Adequate air velocity over the finned surface must be maintained.
d) Circuiting should minimize the performance of the water flow versus the pressure drop through the coil.
e) The bottom connection should always be the water inlet.

Answer: D