Forward curved fans

Forward curved fans

a) require larger size shafts than backward inclined fans
b) are desirable when air handling units have two or more fans mounted on a common shaft
c) operate at higher speeds than backward inclined fans
d) are quieter than backward inclined fans
e) are more desirable for large fans






Answer: B

Control of the static pressure and horsepower requirements at a given speed is obtained by using

Control of the static pressure and horsepower requirements at a given speed is obtained by using

a) direct drives
b) fluid drives
c) outlet damper control
d) variable inlet vane control
e) belt guards







Answer: D

Centrifugal fans are classified as

Centrifugal fans are classified as

a) backward inclined
b) straight
c) backward inclined with airfoil blades
d) forward curved
e) all of the above







Answer: E

When comparing the tube axial fan with the vane axial fan the main difference between the two is the

When comparing the tube axial fan with the vane axial fan the main difference between the two is the

a) noise output
b) location of the fans in the system
c) location of the fan bearings
d) size of the two units
e) motion of the discharge air






Answer: E

The group of fans which consist of a rotor or wheel having several radial blades, which is mounted on a shaft within the fan housings is

The group of fans which consist of a rotor or wheel having several radial blades, which is mounted on a shaft within the fan housings is

a) Axial flow
b) Centrifugal
c) Both Axial flow and Centrifugal
d) Archial flow
e) None of the above







Answer: B

Backward inclined centrifugal fans:

Backward inclined centrifugal fans:

a. Require more horsepower than the forward curved fans to deliver a specified volume of air
b. Are quieter than forward curved fans
c. Are less efficient than forward curved fans
d. Operate at lower speeds than forward curved fans
e. Are noisier than forward curved fans






Answer: B