MFC Series Boiler Vent and Combustion Air Guide
TAG-0080_OG
•
GF-148-V
•
3/29/2023
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TABLE 5: Ducted Combustion Air Duct Pressure Drop (Eq. Ft.)
for
MFC 10000
MMBTU Boiler
Inlet Duct
& No.
Boilers
Duct Section
Type
OUTSIDE AIR TEMPERATURE (°F)
-30 °F
-15 °F
0 °F
20 °F
40 °F
60 °F
80 °F
100 °F
120 °F
16" Duct
Single
Boiler
Straight Run
0.29
0.31
0.32
0.34
0.37
0.39
0.42
0.44
0.47
90° Elbow
3.12
3.28
3.44
3.67
3.91
4.17
4.45
4.75
5.07
45° Elbow
2.44
2.56
2.68
2.86
3.05
3.26
3.47
3.71
3.95
Ent. Loss
8.78
9.21
9.66 10.31
11.00
11.73
12.52
13.35
14.25
18" Duct
Single
Boiler
Straight Run
0.16
0.17
0.18
0.19
0.20
0.22
0.23
0.25
0.26
90° Elbow
1.85
1.94
2.04
2.18
2.32
2.48
2.64
2.82
3.01
45° Elbow
1.45
1.52
1.59
1.70
1.81
1.93
2.06
2.20
2.35
Ent. Loss
5.48
5.75
6.03
6.43
6.86
7.32
7.81
8.34
8.89
20" Duct
Two
Boilers
Straight Run
0.36
0.38
0.39
0.42
0.45
0.48
0.51
0.54
0.58
90° Elbow
4.64
4.87
5.11
5.45
5.82
6.21
6.62
7.07
7.54
45° Elbow
3.62
3.80
3.99
4.25
4.54
4.84
5.17
5.51
5.88
Ent. Loss
14.38
15.09
15.83 16.89
18.01
19.22
20.51
21.88
23.34
22" Duct
Two
Boilers
Straight Run
0.22
0.23
0.24
0.26
0.28
0.30
0.32
0.34
0.36
90° Elbow
3.04
3.19
3.34
3.57
3.80
4.06
4.33
4.62
4.93
45° Elbow
2.37
2.48
2.60
2.78
2.96
3.16
3.37
3.60
3.84
Ent. Loss
9.82
10.30
10.81 11.53
12.30
13.13
14.01
14.94
15.94
22" Duct
Three
Boilers
Straight Run
0.48
0.51
0.53
0.57
0.60
0.64
0.69
0.73
0.78
90° Elbow
6.83
7.17
7.52
8.02
8.56
9.13
9.74
10.39
11.09
45° Elbow
5.32
5.58
5.86
6.25
6.67
7.11
7.59
8.10
8.64
Ent. Loss
22.10
23.18
24.33 25.95
27.68
29.54
31.51
33.62
35.87
24" Duct
Three
Boilers
Straight Run
0.31
0.33
0.34
0.36
0.39
0.41
0.44
0.47
0.50
90° Elbow
4.61
4.84
5.08
5.42
5.78
6.17
6.58
7.02
7.49
45° Elbow
3.59
3.77
3.95
4.22
4.50
4.80
5.12
5.47
5.83
Ent. Loss
15.60
16.37
17.18 18.32
19.55
20.85
22.25
23.74
25.33
24" Duct
Four
Boilers
Straight Run
0.54
0.57
0.60
0.63
0.68
0.72
0.77
0.82
0.88
90° Elbow
8.20
8.61
9.03
9.63
10.28
10.96
11.70
12.48
13.32
45° Elbow
6.39
6.70
7.03
7.50
8.00
8.53
9.11
9.72
10.37
Ent. Loss
27.74
29.10
30.54 32.57
34.75
37.07
39.56
42.20
45.03
26" Duct
Four
Boilers
Straight Run
0.36
0.38
0.40
0.42
0.45
0.48
0.51
0.55
0.58
90° Elbow
5.68
5.96
6.26
6.68
7.12
7.60
8.11
8.65
9.23
45° Elbow
4.43
4.64
4.87
5.20
5.55
5.92
6.31
6.74
7.19
Ent. Loss
20.14
21.13
22.17 23.65
25.23
26.92
28.72
30.64
32.69
NOTES:
1) Calculation assumes
2335 scfm
per boiler at full fire rate
2) Units for "Straight Run" pressure drop values are (eq. ft. / foot)
3) Units for "Elbows" and "Ent. Loss" are (equivalent feet / item)
