I was recently advised by my new boss ( structural engineer ) that restrooms should be under negative pressure per industry standards.
I understand that the new International Mechanical Code requires exhaust at 75 cfm per water closet or urinal, but I see nothing that requires this to be continuously exhausted or even that a restroom must be negatively pressurized.
Does that mean that one exhausts a total of 150 cfm if you have a toilet and a urinal or do you exhaust 75 cfm & choose one or the other as the basis for design?
If you did exhaust either 75 cfm or 150 cfm then would it not be possible to supply an equal amount of cfm without negative pressurization, generally with the supply air towards the entry & exhaust over the smelly areas?
A final question, can odors be prevented from passing through a door crack when the door is open thus causing depressurization to occur? Or is it possible for hydrogen sulfide ( rotton egg odor ) to travel from a point of high concentration to a point of low concentration irregardless of pressurization? I have driven by cattle farms in Nebraska that seem to emanate odors upwind for some reason.
Recent observations lead me to believe that industry generally has applied manual or automatic motion sensors at exhaust fan switches in rest rooms in the interest of energy conservation. Hopefully, this can continue to be the case. If one is concerned about odors, apply trap primers to floor drains, and install automatic flush valves at urinals & waterclosets.
However, I have come to the conclusion that I am an idiot since my boss tells me that I am. Don't tell anyone that I wrote these questions as I am sure that I could be fired for not being knowledgable.