"m Ransley" wrote in message
...
My apt building with a 1.6 million btu boiler has a
window cracked 1" and the flame is adjusted by a tech with a Bachrach
set up and he says oxygen, color and burner efficiency are tops. boiler
is in a small room, heats 16 units steam heat. Infiltration does the
rest.

I wonder how much, if any, difference it would be with a larger vent
instead of infiltration. I run a large boiler in one of our buildings and it
has a motorized louver. You need a winter coat if you stand in front of the
boiler when the blower is running for combustion. The boiler room is
otherwise closed off by a door. This is in an old building with plenty of
drafts and infiltration, but spread out over four floors and distances of
200 feet or so.