Stack
Diam.
(in.)
Table 1.8.15C: Approximate Stack Capacities (MBH)
(Based on Atmospheric Boiler with Draft Hood)
5
7
10
12
15
20
25
30
35
40
45
50
60
70
80
90
100
125
150
200
6
100
120
140
150
170
200
220
250
270
280
300
320
350
380
400
430
450
510
550
640
7
130
160
190
210
240
270
310
340
360
390
410
430
480
510
550
580
620
690
760
870
8
180
210
250
280
310
360
400
440
480
510
540
570
620
670
720
760
810
900
990
1140
9
220
270
320
350
390
450
510
560
600
640
680
720
790
850
910
970
1020
1140
1250
1450
10
280
330
400
430
490
560
630
690
750
800
850
890
980
1060
1130
1200
1260
1410
1550
1790
12
400
480
570
630
700
810
910
1000
1080
1150
1220
1290
1410
1520
1630
1730
1820
2040
2330
2580
14
550
650
780
860
960
1110
1240
1360
1470
1570
1660
1750
1920
2070
2220
2350
2480
2770
3040
3510
16
720
850
1020
1120
1250
1450
1620
1770
1920
2050
2170
2290
2510
2710
2900
3070
3240
3620
3970
4590
18
910
1080
1290
1420
1590
1830
2050
2250
2430
2590
2750
2900
3180
3430
3670
3890
4100
4590
5030
5810
20
1130
1340
1600
1750
1960
2260
2530
2770
3000
3200
3400
3580
3920
4240
4530
4810
5070
5670
6210
7170
22
1370
1620
1940
2120
2370
2740
3060
3360
3630
3880
4110
4340
4750
5130
5480
5820
6130
6860
7510
8680
24
1630
1930
2300
2530
2820
3260
3650
4000
4320
4610
4900
5160
5650
6110
6530
6920
7300
8160
8940
10330
26
1910
2260
2710
2960
3320
3830
4280
4690
5070
5420
5750
6060
6640
7170
7660
8130
8570
9580
10490
12120
28
2220
2630
3140
3440
3850
4440
4970
5440
5880
6280
6660
7030
7700
8310
8890
9430
9940
11110
12170
14060
30
2550
3010
3600
3950
4420
5100
5700
6250
6750
7210
7650
8070
8840
9540
10200
10820
11410
12760
13970
16140
32
2900
3430
4100
4490
5020
5800
6490
7110
7680
8210
8710
9180
10050
10860
11610
12310
12980
14510
15900
18360
34
3270
3870
4630
5070
5670
6550
7320
8020
8670
9270
9830
10360
11350
12260
13110
13900
14650
16390
17950
20730
36
3670
4340
5190
5670
6360
7350
8210
9000
9720
10390
11020
11620
12730
13750
14700
15590
16430
18370
20120
23240
48
6530
7730
9230
10120
11310
13060
14600
16000
17280
18470
19600
20660
22630
24400
26130
27710
29210
32660
35780
41320
54
8260
9780
11690
12810
14320
16530
18480
20250
21870
23380
24800
26140
28640
30930
33070
35080
36970
41340
45290
52290
60
10200
12070
14430
15810
17680
20410
22820
25000
27000
28870
30620
32280
35360
38190
40830
43310
45650
51040
55910
64560
72
14700
17390
20780
22770
25460
29400
32870
36000
38890
41570
44100
46480
50920
55000
58800
62360
65740
73500
80510
92970
NOTE: The above vent input capacities in MBH (thousands of Btu/hr) are sea level ratings for double wall or insulated vents allowing for a system K factor of
7.5. Apply the correction factors for altitude, other k-factors and boiler draft control correction factors.
Summary of Contents for Forced Draft Steam Boilers
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