Auto-Zone Control Systems Auto-Zone Plus Systems Installation & Operation (Version 03A) - Manual (Page 27)

Auto-Zone Plus Section 1
Design Guide 1-23
Table 1-2: Round Damper Dimensional Data
Pressure Independent Round Damper “K” Factor
Pressure Independent Round Air Dampers utilize “K” factors to correctly measure and
read CFM values. These “K” factors represent the airflow that will pass through a given
size damper at 1” of velocity pressure. These “K” factors must be programmed into the
control system for all pressure independent dampers. See Table 1-3 for a list of “K”
factors by round damper diameter used.
Table 1-3: Pressure Independent “K” Factors
VAV/Zone Round Damper Dimensional
Data
Duct Diameter A B C
6 ″ 19.00 5.88 9.38
8 ″ 19.00 7.88 11.38
10 ″ 19.00 9.88 13.38
12 ″ 22.00 11.88 15.38
14 ″ 22.00 13.88 17.38
16 ″ 22.00 15.88 19.38
1/2" Foil Faced
Insulation
Actuator
Zone Controller
Round Damper
Blade Assembly
Control Enclosure
(Cover Removed)
AIR FLO W AIR FLO W
Flow Probe “K” Factor Chart
K Factor = CFM Flow @ 1” Velocity Pressure
Damper Diameter Flow Probe “K” Factor
6 ″
474
8 ″
950
10 ″
1417
12 ″
2120
14 ″
2908
16 ″
3700