Duct fitting pressure drop coefficients for
round transition
From ASHRAE (1989), with permission
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Values for C
q, deg | |||||||||||
10 |
15 |
20 |
30 |
45 |
60 |
90 |
120 |
150 |
180 |
||
A0 / A1 |
0.06 |
0.21 |
0.29 |
0.38 |
0.60 |
0.84 |
0.88 |
0.88 |
0.88 |
0.88 |
0.88 |
0.1 |
0.21 |
0.28 |
0.38 |
0.59 |
0.76 |
0.80 |
0.83 |
0.84 |
0.83 |
0.83 |
|
0.25 |
0.16 |
0.22 |
0.30 |
0.46 |
0.61 |
0.68 |
0.64 |
0.63 |
0.62 |
0.62 |
|
0.5 |
0.11 |
0.13 |
0.19 |
0.32 |
0.33 |
0.33 |
0.32 |
0.31 |
0.30 |
0.30 |
|
1* |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
|
2 |
0.20 |
0.20 |
0.20 |
0.20 |
0.22 |
0.24 |
0.48 |
0.72 |
0.96 |
1.0 |
|
4 |
0.80 |
0.64 |
0.64 |
0.64 |
0.88 |
1.1 |
2.7 |
4.3 |
5.6 |
6.6 |
|
6 |
1.8 |
1.4 |
1.4 |
1.4 |
2.0 |
2.5 |
6.58 |
10 |
13 |
15 |
|
10 |
5.0 |
5.0 |
5.0 |
5.0 |
6.5 |
8.0 |
19 |
29 |
31 |
43 |
*for equal-area transition from square to round, use C = 0.15.