System effect factors for various duct outlet lengths
From ASHRAE (1988), with permission
![]() |
Notes:
|
KSEF values for various outlet duct lengths
Ratio of blast area to outlet area |
No duct |
12% effective duct length |
25% effective duct length |
50% effective duct length |
100% effective duct length |
0% |
50% pressure recovery |
80% pressure recovery |
90% pressure recovery |
100% pressure recovery |
|
0.4 |
2.0 |
1.00 |
0.40 |
0.18 |
no system effect factor |
0.5 |
2.0 |
1.00 |
0.40 |
0.18 |
|
0.6 |
1.00 |
0.66 |
0.33 |
0.14 |
|
0.7 |
0.80 |
0.40 |
0.14 |
- |
|
0.8 |
0.47 |
0.22 |
0.10 |
- |
|
0.9 |
0.22 |
0.14 |
- |
- |
|
1.0 |
- |
- |
- |
- |