I'm looking to get some opinions on the design of our ventilation systems installed were I work. I am by no means an HVAC expert, but probably know enough to be dangerous !
I work in a facility that sorts small packages and houses between 150-200 delivery vehicles inside, mostly diesel.
Around the beginning of winter, I noticed fumes to be worse in the building, I had found out, that a section of the building's exhaust fans where 1/2 of the vehicles park were disabled. I had brought this to the attention of the plant engineering people, and the next day, ALL of our exhaust fans were shut off (we had the ability to turn on fans in my area as needed if it got smoky). I was informed that these exhaust fans are obsolete because we employ 2 Rapid 4000 AM Direct Fired Heating Unit with CO sensors and when the air gets too bad the sensors will draw in more fresh air, and if it gets real bad, 1 unit goes 100% fresh air, the other 100% Exhaust. I was told if fumes get bad to crack a pedestrian door and the unit will sense pressure loss and push the fumes out of the building.
It seems to me that the system will be pushing the fumes right past everyones breathable air space instead of exhausting the fumes closest to the source.
4 of the sensors used are CO only, 2 are CO / NO2 (used to sense diesel). It is my opinion that they should not rely on said sensors, seeing how diesel fumes contain MANY other contaminents other than CO / NO2, and it is best to have good circulation PRIOR to setting an alarm! The building is a loose building but when they start and move vehicles and the doors are closed, it can be pretty irritating.
I was hoping someone could shed some light on best practices or industrial hygiene protocol.
Thanks in advance for the help!