Select an Oil Fired Steam Boiler and Avoid Over-Firing and Under-firing

Migan

Select an Oil Fired Steam Boiler and Avoid Over-Firing and

Under-firing.





 





Holohan  laments that

the boiler manufacturers over the years have reduced the water content of their

boilers in order to get better efficiency ratings. The implication is that the

reduction in water content of steam boilers is a negative for steam system.

Like cycling for instance.





 





Most 3 section boilers are rated for 280 sq ft of steam with

a .75 gph nozzle , and have a similar AFUE 

of 85.  The pronounced

variance  among the different brands is

in the amount of water each  boiler

contains.  From about 5 gallons for the

New Yorker and Buderus,  and about 10

gallons each for Burnham, Smith,  and

Williamson, to a high of 17

gallons for the Peerless,





 





I conclude that 

Holohan is suggesting the best choioce is the steam boiler with the

largest water capacity (given that the other 

variables like fuel consumption, steam load, and AFUE are about the same

for each of the boilers.)  Or am I

wrong?





 





Holoran also has a lot to say about the folly of over-firing

and under-firing.





 





Now, if I skip over the three section boiler and instead

hang with the four section boiler like Smith or Williamson, each with 14

gallons of water , and fire with a 0.75 gph nozzle  would I get a steam load and an AFUE rating similar to the three

section boilers?  Does under firing get

into the picture here, or am I good to go with a four section boiler.





 





  So what is up with

Peerless? How do they manage to score average ratings with above average water

content?  And why would I not get

similarly good results with a larger, four section boiler with  14 gallon water capacity, as I would with a

three section 17 gallon capacity 

Peerless.  It would seem to me

that the four section boiler has more heat absorbing surface and ought to

produce steam at least as efficiently as a boiler with three sections.





 





There are a lot of 

used oil fired steam boilers available at token prices and I’m looking

to replace my mothers’ coal fired boiler (refitted with an oil burner in the

fifties) with a sensible and long lasting updated replacement.  Her coal fired  one-pipe steam heating system had no breakdowns for almost a

century.  I’m a life long renter and

this is the first  time I’m dealing with

house heating so please overlook my immaturity with steam heat..