Appendix
EDMMT712101
178
VAM-HVE/HVLT Series
17.5.2 Calculation of pressure loss for straight pipe duct
In the Case of Circular Ducts
(1) Duct Resistance is Found by the Following Formula.
The following formula is generally used to find Pressure Loss rP at time air flows in the straight pipe duct.
Airflow Resistance Coefficient for Main Duct
(2) Method that finds by Air Duct Flow Resistance Chart
Circular Air Duct Flow Resistance Chart (Galvanized Steel Pipe)
Duct resistance
P (Pa) =
λ
× × × v
2
λ:
Friction coefficient of pipe for duct (0.01 to 0.25)
γ:
Specific weight of air (kg/m
3
)
≈
1.20 kg/m
3
L: Duct length (m)
d: Duct diameter (m)
v: Air velocity inside duct (m/sec)
v = ×
Q: Airflow rate (m
3
/h)
Here when we substitute
λ
= 0.01 (in the case that the pipe is extremely smooth)
γ
= 1.2,
P = 0.01 × × × ×
γ
2
L
d
Q
d
2
4
3,600
π
Q
d
2
2
1.2
2
L
d
4
3,600
π
{
}
Duct material
Aluminum flexible duct
Vinyl chloride pipe
Galvanized steel pipe
λ
0.03 to 0.04
0.01 to 0.02
0.016 to 0.025
1000000
800000
600000
400000
200000
100000
80000
60000
40000
20000
10000
8000
6000
4000
2000
1000
800
600
400
200
100
80
60
40
20
10
0.04
0.1
0.2
0.4
1.0
2.0
6.0
10
80
60
40
20
400
350
300
250
200
180
160
140
120
100
90
80
70
60
45
40
35
30
25
20
18
16
14
12
10
9
8
7
6
6
5
4
3
2
4.5
d = 5
3.5
2.5
d = 500cm
0.04
0.1
0.2
0.4
1.0
2.0
6.0
10
80
60
40
20
v = 50.0m/s
40.0
30.0
20.0
15.0
9.0
8.0
7.0
6.0
5.0
4.0
3.0
2.0
1.8
1.6
1.4
1.2
1.0
0.9
0.8
0.7
0.6
0.5
Airflo
w r
ate Q (m
3
/h)
Friction loss coefficient
γ
(Pa/m)
Duct Flow Resistance Chart
Diameter
: 50 cm
Air v
elocity:
10.0 m/s
Summary of Contents for VAM Series
Page 2: ......
Page 4: ...EDMMT712101 2 Table of Contents 17 6 Precautions for Design and Installation 181 ...
Page 56: ...Control System EDMMT712101 54 VAM HVE HVLT Series C 3P343420 1E ...
Page 138: ...Installation Manual EDMMT712101 136 VAM HVE HVLT Series 3P607378 3C ...
Page 139: ...EDMMT712101 Installation Manual VAM HVE HVLT Series 137 3P607378 3C ...
Page 141: ...EDMMT712101 Installation Manual VAM HVE HVLT Series 139 C EM20A032 ...
Page 142: ...Installation Manual EDMMT712101 140 VAM HVE HVLT Series C EM20A032 ...
Page 143: ...EDMMT712101 Installation Manual VAM HVE HVLT Series 141 C EM20A032 ...
Page 147: ...EDMMT712101 Details of Optional Accessories VAM HVE HVLT Series 145 3P607378 3C ...
Page 148: ...Details of Optional Accessories EDMMT712101 146 VAM HVE HVLT Series 3P607378 3C ...
Page 149: ...EDMMT712101 Details of Optional Accessories VAM HVE HVLT Series 147 3P607378 3C ...
Page 150: ...Details of Optional Accessories EDMMT712101 148 VAM HVE HVLT Series 3P607378 3C ...
Page 151: ...EDMMT712101 Details of Optional Accessories VAM HVE HVLT Series 149 3P607378 3C ...
Page 152: ...Details of Optional Accessories EDMMT712101 150 VAM HVE HVLT Series 3P607378 3C ...
Page 155: ...EDMMT712101 Details of Optional Accessories VAM HVE HVLT Series 153 4P457318 1D ...
Page 156: ...Details of Optional Accessories EDMMT712101 154 VAM HVE HVLT Series 4P457318 1D ...
Page 157: ...EDMMT712101 Details of Optional Accessories VAM HVE HVLT Series 155 4P457318 1D ...
Page 158: ...Details of Optional Accessories EDMMT712101 156 VAM HVE HVLT Series 4P457318 1D ...
Page 159: ...EDMMT712101 Details of Optional Accessories VAM HVE HVLT Series 157 4P457318 1D ...
Page 184: ......
Page 185: ......
Page 186: ......
Page 187: ......