Hey, I talked to some guys at the shop today and there was ans ongoing thing at a mental health facility like this. And, after a whole lot of investigating a plumber discovered that the hvac condensate drain had been tied into the sanitary vent system directly allowing the blower to pump sewer gas into the building. The addition of "Memphis pattern deep seal traps" at the sanitary vent and running traps at the units with minivents on the indirect waste solved the problem.