Due to 3 inconsistent signs in the OSB optics lab which stated that the HVAC fan should be on all of the time, Rick and turned it on.  We were anticipating using the small air bake oven on the counter which referenced the fan being on, and then ran into the signs.  We then attempted to follow the signs and turn the fan on, but found that the wall dial would not turn the flow down to the spec on the sign, nor did there appear to be any updraft in the airbake oven.  So, we think the whole airbake exhaust system in the OSB is broke.  We're relocating our bakeout operation to another oven in another building.