MATH PROBLEMS
Part 5: Problems 23.16 Through 23.20
PROBLEM 23.16 The plans require a 200 3 240 duct, but the
attic space is only 160 deep. Properly size the duct to fit within
the attic space and write a request for information (RFI) to in-
form the engineer.
PROBLEM 23.17 The plans require a 480 3 960 with 20
acoustical liner. List the correct duct size to be used on the
shop drawing.
PROBLEM 23.18 The required CFM for a certain room is 800
CFM at a velocity of 600 FPM. If there are four equally sized dif-
fusers, what size square duct would be used? What size round?
PROBLEM 23.19 Convert the following rectangular duct
sizes to round:
120 3 120
240 3 240
300 3 180
480 3 140
1000 3 300
PROBLEM 23.20 Convert the following round duct sizes
to rectangular:
80 5
180 5
600 5
240 5
340 5
Figure P23.15f (continued )
59728_ch23_EOC_ptg01.indd 28 03/02/16 10:38 am