OSB
Series 2 Oil-Fired Steam Boilers – Boiler Manual
Part Number 550-110-772/0816 27
13 Ratings
AHRI Certified Rating
Boiler
model
number
Burner
Capacity
GPH
Heating
Capacity
MBH
Net ratings
Seasonal
efciency
AFUE %
Round
ue
outlet
size
inches
Minimum Chimney
Dimensions
Boiler water
content
(gallons @
normal
waterline)
Draft loss
through
boiler
inches W.C.
Steam
sq. feet
Steam
MBH
Rectangle
inches
Round
inches
Height
feet
Notes 1 & 2 Note 3 Note 4 Note 5 Note 6
OSB-3
0.95 114 358 86 84.0% 7 8 x 8 6 15 10.7 0.020
OSB-4
1.20 144 450 108 84.0% 7 8 x 8 6 15 12.5 0.010
OSB-5
1.45 174 546 131 83.9% 7 8 x 8 7 15 14.2 0.015
OSB-6
1.75 210 658 158 83.7% 7 8 x 8 7 15 16 0.015
Notes
1. MBHreferstothousandsofBtuperhour.
2. Base on 140,000 Btu per gallon of oil.
3. BasedonstandardtestproceduresprescribedbytheUnitedStatesDepartmentofEnergy,withcombustionconditions13.5%CO
2
.
4. Net ratings are based on net installed radiation of sufficient quantity for the requirements of the building and nothing need be
addedfornormalpipingandpickup.Ratingsarebasedonapipingandpickupallowanceof1.333.Anadditionalallowance
should be made for unusual piping and pickup loads.
5. See page 6 for minimum breeching diameter.
6. Listeddraftlossesareforfactory-shippedsettings.
7. OSBboilersareASMEratedfor50psigworkingpressure.
DOE
®