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APPENDIX 2 - MANUFACTURER BOX CONSTANTS
The following tables show flow calculation constants for the most commonly used manufacturers of variable air volume
terminals.
Manufacturers Listed:
Carnes Company
Environmental Technologies, Inc. (ETI)
Krueger
Metal Industries
Price Industries
Redd-I
Trane Company
Temperature Industries
Titus
Tuttle & Bailey
York Industries
Damper Only Installations
Although accurate at the time of publication, these numbers are subject to change without notice. Consult the
manufacturer’s technical data for further information on your particular box.
CARNES COMPANY
Box Type & Model
Inlet Size (in.)
CFM @ 1"
Area
K (Box Constant)
5" Round
NA
0.136
2.42
Single Duct: AVCC / AVWC / AVEC
6" Round
NA
0.196
2.37
7" Round
NA
0.267
2.40
Constant Fan: ACFB
8" Round
NA
0.349
2.41
10" Round
NA
0.545
2.61
Intermittent Fan: ASFB
12" Round
NA
0.785
2.35
14" Round
NA
1.068
2.42
Dual Duct: ADCC
16" Round
NA
1.396
2.38
9 x 12
NA
0.750
2.37
16 x 18
NA
2.000
2.30
90 deg travel, clockwise to close
16 x 24
NA
2.670
2.40
