True/False
Indicate whether the sentence or statement is true
or false.


1.

The
amount of air flow (CFM) that is delivered by a blower depends on the resistance (pressure) that the
blower has to work against?
True or False


2.

To
meet the objective of good duct design, the duct system must be designed so that the air flow
resistance , in terms of static pressure drop, matches the external static pressure that is developed
by the blower when the blower delivers the desired CFM?
True or
False

Multiple Choice
Identify the
letter of the choice that best completes the statement or answers the question.


3.

A
friction rate is equal to the pressure loss that occurs between two point in a duct system that are
separated by a specific distance.Friction charts and duct slide rules use 100’ for the reference
distance. What would you assume the pressure drop would be in a typical residential duct
system. a.  0.5 “
W.C.  c.  5”
W.C.  b.  .1”
W.C.  d.  .8”
W.C     


4.

The
formula for finding FR when the system pressure drop is know is? a.  FR=PD
x100
100  c.  PD=.5
x100
100  b.  PD=FR
x100
100  d.  FR=.8x100
100     


5.

How
do you determine available static pressure when doing your design? a.  Exam all device
pressure losses and subtract from manufacturers external static pressure at your desired
CFM  c.  Measure in
field  b.  Blower static pressure
measurement  d.  Calculated
CFM     


6.

Using
your ductulator with a friction rate of 0.05 for galvanized duct @ 480 CFM what would the size of
your round duct be for these conditions?


7.

Using
your ductulator with a friction rate of 0.05 for galvanized duct @ 480 CFM what would the friction
rate be for these conditions? a.  600 fpm  c.  800 fpm  b.  1200
fpm  d.  400
fpm     


8.

If
you have a round duct diameter of 8” what would be the round duct area in square
inches?


9.

If
you want to deliver in a rectangular duct which is 8 x ? an amount of air equal to 200 CFM at a 0.05
friction rate, what would the 8 x ? be?


10.

To
deliver 150 CFM of air to a space with a friction rate of 0.05 what size wire helical flexible duct
would you need?


11.

In a
residence what would be the problem with a main duct run delivering 1,000 CFM @0.05 friction rate
with a size being 50 x 8? a.  Velocity to low and duct costly to fabricate, too
large  c.  Velocity to
high  b.  Nothing  d.  FPM to
high     


12.

If my
duct system pressure drop is equal to 0.05 W.C and my duct is to delivery 200 CFM at a length of 200
feet, what would be my required design friction rate?
