4 - ratings & capacities – Dunkirk Excelsior EXB Series User Manual
Page 8
8
GPH = U.S. Gallons per Hour
Mbh = 1000 Btu (British thermal units) per hour.
psi = Pounds per square inch
*MAWP = Maximum allowable working pressure. This low pressure oil fired hot water boiler is constructed and
hydrostatically tested for maximum working pressure of 65 psi in accordance with the latest revision of the A.S.M.E.
(American Society of Mechanical Engineers) Boiler and Pressure Vessel Code Section IV Standards for heating boilers.
AFUE= Annual Fuel Utilization Efficiency
Heating Capacity and AFUE based on 13.1% CO
2
(13.5% CO
2
at 0.95 GPH and 1.10 GPH), -0.02” w.c. draft in breech, and
# 1 smoke or less. Testing is done in accordance with U.S. DOE (Department of Energy) test procedure.
Heating Capacity indicates amount of heat available after subtracting losses up the stack. Remaining heat is available
to heat water. Small portion is heat from jacket and surfaces of boiler and this heat stays in structure. Net AHRI rating
represents portion of remaining heat applied to heat radiation or terminal units (i.e. finned tube baseboard, cast iron
radiators, radiant floor, etc.). Difference between Heating Capacity and Net AHRI Rating, called piping and pickup
allowance, establishes reserve for heating volume of water in system and offsetting heat losses from system piping. Net
AHRI ratings shown are based on piping and pickup factor of 15% in accordance with AHRI Standard as published by
Hydronics Institute.
Net AHRI rating of boiler selected should be greater than or equal to calculated peak heating load (heat loss) for building
or area(s) served by boiler and associated hot water heating systems. Consult manufacturer before selecting boiler for
installations having unusual piping and pickup requirements.
4 - RATINGS & CAPACITIES
Table 1 RATINGS & CAPACITIES
OIL-FIRED HOT WATER BOILERS
Number
of
Sections
Firing
Rate
[GPH]
Input
[Mbh]
Heating
Capacity
[Mbh]
Net
AHRI
Rating
[Mbh]
*MAWP
Water
[psi]
AFUE
[%]
Min. relief
Valve
Capacity
[Mbh]
Max.
Water
Temp
[°F]
Chimney
Liner Size
Round
[Inches]
Chimney
Liner
Size
[Square
Inches]
Flue
Size
[Inches]
4
0.75
105
91
79
65
86.0
91
250
6
6 3/4
5
4
0.95
133
114
99
65
85.0
115
250
6
6 3/4
5
4
1.10
154
132
115
65
84.0
132
250
6
6 3/4
5
5
1.00
140
122
106
65
86.5
122
250
6
6 3/4
5
5
1.15
161
139
121
65
85.0
139
250
6
6 3/4
5
5
1.35
189
161
140
65
84.0
161
250
7
6 3/4
5
6
1.30
182
159
138
65
86.5
159
250
6
6 3/4
5
6
1.45
203
176
153
65
85.0
176
250
7
6 3/4
5
6
1.65
231
198
172
65
84.0
198
250
7
6 3/4
5
7
1.65
231
201
175
65
86.0
201
250
7
6 3/4
6
7
1.80
252
217
189
65
85.0
217
250
7
6 3/4
6
7
1.90
266
228
198
65
84.0
227
250
8
6 3/4
6