SMD-401M
Pressure Drop Data
This pressure drop testing was conducted in accordance with AMCA Standard 500-D using the three configurations shown.
All data has been corrected to represent standard air at a density of .075 lb/ft
3
(1.201 kg/m
3
).
Actual pressure drop found in any HVAC system is a combination of many factors. This pressure drop information along with
an analysis of other system influences should be used to estimate actual pressure losses for a damper installed in a given
HVAC system.
5D
6D
5D
D
4 (W) (H)
3.14
AMCA Test Figures
Figure 5.3
Illustrates a fully ducted damper. This
configuration has the lowest pressure drop of the
three test configurations because entrance and
exit losses are minimized by straight duct runs
upstream and downstream of the damper.
Figure 5.2
Illustrates a ducted damper exhaust-
ing air into an open area. This configuration has
a lower pressure drop than Figure 5.5 because
entrance losses are minimized by a straight duct
run upstream of the damper.
Figure 5.5
Illustrates a plenum mounted damper.
This configuration has the highest pressure drop
because of extremely high entrance and exit
losses due to the sudden changes of area in the
system.
Damper Size
12 in. x 12 in.
(305mm x 305mm)
Velocity (fpm)
4 5 6
7
8 9 10
x 100
x 1000
Pr
essur
e Loss (in. wg
)
10.0
9.0
8.0
7.0
6.0
5.0
4.0
3.0
2.0
2 3 4 5 6
7
8 9 10
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.10
0.09
0.08
0.07
0.06
0.05
0.04
0.03
0.02
5.5
5.2
5.3
Damper Size
24 in. x 24 in.
(610mm x 610mm)
Velocity (fpm)
4 5 6 7 8 9 10
x 100
x 1000
Pr
essur
e Loss (in. wg
)
10.0
9.0
8.0
7.0
6.0
5.0
4.0
3.0
2.0
2 3 4 5 6 7 8 9 10
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.10
0.09
0.08
0.07
0.06
0.05
0.04
0.03
0.02
5.5
5.2
5.3
Damper Size
36 in. x 36 in.
(914mm x 914mm)
Velocity (fpm)
4 5 6 7 8 9 10
x 100
x 1000
Pr
essur
e Loss (in. wg
)
10.0
9.0
8.0
7.0
6.0
5.0
4.0
3.0
2.0
2 3 4 5 6 7 8 9 10
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.10
0.09
0.08
0.07
0.06
0.05
0.04
0.03
0.02
5.5
5.2
5.3
Figure 5.3
Figure 5.2
Figure 5.5
