Downsizing boiler replacement

Kjmass1

I have 200k/157k one pipe steam boiler from the 70s. After a couple remodels I’m only using 300 EDR as we’ve removed some radiators so we are really oversized. All things equal, if I swapped it out for say a 100k or appropriately sized boiler, what kind of gains would I be looking at? Or would the smaller boiler just have to run longer? Can it make the same amount of steam with the same run times but burning half the natural gas?

Thanks
Kevin

The Steam Whisperer

I have found when using boiler of nearly identical AFUE, both equipped with stack dampers, that the fuel usage drops about 12% when going from a boiler twice as large as needed to one just the right size. Since you old boiler probably doesn't have a stack damper, the savings will probably ve several points higher. If the old boiler is in bad shape, that could amount to more savings.

Kjmass1

> @The Steam Whisperer said:
> I have found when using boiler of nearly identical AFUE, both equipped with stack dampers, that the fuel usage drops about 12% when going from a boiler twice as large as needed to one just the right size. Since you old boiler probably doesn't have a stack damper, the savings will probably ve several points higher. If the old boiler is in bad shape, that could amount to more savings.

Thanks. It doesn’t have a stack damper and combustion efficiency is worth a couple more points as I think mine is 80% (or was). I know my near boiler piping isn’t ideal so I’m wondering if 20% is possible or a pipe dream?

EBEBRATT-Ed

With 300 edr you need about 117,000 input

The Steam Whisperer

just right for a little 63 Peerless