3
1) Ratings are at sea level to 2,000 feet. For altitudes above 2,000 feet, reduce all ratings 4% for each 1,000 feet above sea level
2) Net steam ratings based on an allowance of 1.333 (300-1600), 1.327 (1700), 1.319 (1800), 1.313 (1900), 1.307 (2000), 1.301 (2100), 1.296 (2200),
1.292 (2300), 1.290 (2400), and 1.288 (2500-3000). Contact Technical Support before selecting boiler for installations having unusual piping and pick-up
factors, such as intermittent system operations, extensive piping systems, etc.
3) Ratings in square feet are computed at 240 Btuh/square foot for steam boilers.
4) Ratings based on 33,500 Btuh per horsepower.
5) Pressure drop based on given fl ow from single outlet and returning to single inlet at the opposite end of the boiler.
6) Chimney sizes shown are one option based on a typical venting system as shown in Figure 6, and sized according to the National Fuel Gas Code, assuming Type B
double wall vent and vent connectors, Other venting system designs are acceptable as shown on Flue Connection And Venting section of this manual. For further
chimney design and sizing information, consult the National Fuel Gas Code, ANSI Z223.1/NFPA 54-latest revision, or ASHRAE6 HVAC Systems and Equipment Handbook,
Chimney, Gas Vent, and Fireplace Systems, or the Standard for Chimneys, Fireplaces, Vents, and Solid Fuel Burning Appliances. NFPA 211. Follow standard engineering
practice.
Ratings and Capacities - Chart 1
Input/Size
(Mbh)
Output (1)
Net AHRI
Ratings (2)
Flue Outlet No.
& Size
Chimney
Size (6)
Flue
Collector
Size to
Chimney
Horsepower
Gross
Output (4)
Therm.
Eff.
Pressure Drop
Thru Water
Boiler (5)
Gross
Output
Mbh
Steam
(Sq Ft)
Steam
Mbh
8”
10”
12”
I.D. x Ht.
GPM
In.
Water
300
400
500
233
310
388
729
971
1213
175
233
291
1
1
1
8”x20’
10”x20’
12”x20’
8
10
12
6.96
9.25
11.58
77.5
18.9
37.8
0.10
0.50
77.5
25.2
50.4
0.27
0.86
77.5
31.5
63.0
0.40
1.20
600
700
800
900
1000
465
543
620
698
775
1454
1696
1938
2183
2421
349
407
465
524
581
2
1
1
2
1
1
2
12”x20’
12”x20’
14”x20’
14”x20’
14”x20’
12
12
14
14
14
13.88
16.21
18.51
20.84
23.13
77.5
37.8
75.6
0.50
1.70
77.5
44.1
88.2
0.70
2.50
77.5
50.4
100.8
0.88
2.90
77.5
56.7
113.4
1.10
3.80
77.5
63.0
126.0
1.30
4.00
1100
1200
1300
1400
1500
853
930
1008
1085
1163
2667
2908
3150
3392
3633
640
698
756
814
872
1
1
2
3
1
2
2
3
16”x20’
16”x20’
16”x20’
18”x20’
18”x20
16
16
16
18
18
25.46
27.76
30.09
32.39
34.72
77.5
69.3
138.6
1.50
5.00
77.5
75.6
151.2
1.80
6.00
77.5
81.9
163.8
2.00
5.60
77.5
88.2
176.4
2.40
7.00
77.5
94.5
189.0
2.60
8.30
1600
1700
1800
1900
2000
1240
1318
1395
1473
1550
3875
4138
4408
4675
4942
930
993
1058
1122
1186
1
4
1
2
1
2
2
3
4
18”x20’
18”x20’
20”x20’
20”x20’
20”x20
18
18
20
20
20
37.01
39.34
41.64
43.97
46.27
77.5
100.8
201.0
2.80
9.60
77.5
107.1
214.2
3.15
10.30
77.5
113.4
226.8
3.50
11.00
77.5
119.7
239.4
4.00
12.50
77.5
126.0
252.0
4.50
14.00
2100
2200
2300
2400
2500
1628
1705
1783
1860
1938
5213
5483
5750
6008
6271
1251
1316
1380
1442
1505
2
3
2
1
3
2
3
4
5
20”x20’
22”x20’
22”x20’
22”x20’
22”x20
20
22
22
22
22
48.60
50.90
53.22
55.52
57.85
77.5
132.3
264.6
4.95
16.00
77.5
138.6
277.2
5.40
18.00
77.5
144.9
289.8
5.70
17.00
77.5
151.2
302.4
8.00
19.00
77.5
157.5
315.0
8.00
20.50
2600
2700
2800
2900
3000
2015
2093
2170
2248
2325
6517
6771
7021
7271
7521
1564
1625
1685
1745
1805
2
1
1
2
1
4
4
4
5
6
22”x20’
24”x20’
24”x20’
24”x20’
24”x20
22
24
24
24
24
60.15
62.48
64.78
67.10
69.40
77.5
163.8
327.6
7.00
24.00
77.5
170.1
340.2
7.50
24.00
77.5
176.4
352.8
8.00
26.00
77.5
182.75
365.5
8.50
27.50
77.5
189.1
378.2
9.00
9.00
RATINGS AND CAPACITIES
