Looks like for the battle for the air, the fan won !
And your CO levels should have remained at zero .... I would be more worried about CO2 levels rising to lower the O2 content. Remember, our atm. is not 100% oxygen.
All is well .. looks like the small amt of sulfur (SOx after burning) in the coal helped you out. Your nose can detect this at < 1 ppm ... one of the few chemicals it can smell at such low levels (why? I don't know why we developed this ability ~ its not like we come across SOx that often).
http://www.cdc.gov/niosh/docs/81-123/pdfs/0575.pdf for some more information on sulfur dioxide...a neat little compound.
Thank your mother kids. Thanks mom.
I once talked to someone that did just that...he had a big hand fed boiler and burned bituminous coal. Smoke spilling out of the loading door was a problem, so he installed an exhaust fan backwards so it would pressurize the boiler room. He said it worked excellent, prevented any smoke spillage and really got the fire cooking after a reload.
