Duct fitting pressure drop coefficients for
converging round tee
From ASHRAE (1989), with permission
![]() |
Branch Cc,b
Ab / Ac | ||||||||
0.1 |
0.2 |
0.3 |
0.4 |
0.6 |
0.8 |
1.0 |
||
Vb / Vc | 0.0 |
-1.0 |
-1.0 |
-1.0 |
-0.90 |
-0.90 |
-0.90 |
-0.90 |
0.1 |
0.40 |
-0.37 |
-0.51 |
-0.46 |
-0.50 |
-0.51 |
-0.52 |
|
0.2 |
3.8 |
0.72 |
0.17 |
-0.02 |
-0.14 |
-0.18 |
-0.24 |
|
0.3 |
9.2 |
2.3 |
1.0 |
0.44 |
0.21 |
0.11 |
-0.08 |
|
0.4 |
16 |
4.3 |
2.1 |
0.94 |
0.54 |
0.40 |
0.32 |
|
0.5 |
26 |
6.8 |
3.2 |
1.1 |
0.66 |
0.49 |
0.42 |
|
0.6 |
37 |
9.7 |
4.7 |
1.6 |
0.92 |
0.69 |
0.57 |
|
0.7 |
43 |
13 |
6.3 |
2.1 |
1.2 |
0.88 |
0.72 |
|
0.8 |
65 |
17 |
7.9 |
2.7 |
1.5 |
1.1 |
0.86 |
|
0.9 |
82 |
21 |
9.7 |
3.4 |
1.8 |
1.2 |
0.99 |
|
1.0 |
101 |
26 |
12 |
4 |
2.1 |
1.4 |
1.1 |
Main Cc,s
Vb / Vc | 0 |
0.1 |
0.2 |
0.3 |
0.4 |
0.5 |
0.6 |
0.7 |
0.8 | 0.9 | 1.0 |
Cc,s | 0 | 0.16 | 0.27 | 0.38 | 0.46 | 0.53 | 0.57 | 0.59 | 0.60 | 0.59 | 0.55 |