how to size Heating Boiler with no Btu info on tag. 1960 national boiler

mempho

The tag says :

national boiler

size : 19w55

sq'steam 1976000

sq'water 10550

sn# 4563

btu:   

the info on the btu looks like it was never stamped. this is an atmospheric hot water boiler with two watts 3/4 174a 30 psi relief valves. it has a couple of end suction pumps that pump through it. I am struggling to figure out the size of this unit. it has a couple of 8"-10" stacks on it. nat gas burners on the bottom. this is the heat for an old Catholic school. anyone have any info on this boiler model number? or how to size based on the sq' of water? any help would be appreciated

Alan (California Radiant) Forbes

Boiler Size

If the boiler is rated at 180 degrees, the output is 170 BTU's per square foot. So:



10,550 square feet x 170 BTU/square foot = 1,793,500 BTU



Deduct 15% for your I=B=R rating.

Tim McElwain

The size

19W55 I believe the 55 may be horsepower so 33,479 BTU's per hr times 55 + 1,841,345 BTU's

Charlie from wmass

Please tell me

you are not sizing the new boiler off the old rating plate. I looked in my National book but your boiler is newer than my book.