That is an excellent point as even flue-dried tobacco is vented, up the flue.

 

For anyone interested is seeing one of these alleged brick tobacco buildings, there is one on the Berne Heritage Days Barn Tour, July 16th at the Jacob Post Barn/Farm.  Take a smoker who has quit with you and they will be able to tell you if the building was ever used to cure tobacco.  They will want a cigarette so I'll let you know after I visit it.(8^)

R. Miner