Place the unit in one of the many rooms that needs it, preferably as close as possible to an open air vent. Have the janitorial staff set up and turn the unit on before they leave for the night, so it can do its thing all night long. Have whoever is on location first in the morning turn the ozone generator off, and crack a few windows. This will allow a fresh circulation of air before the establishment opens for business for the day. Allow the entire area to air out for at least an hour before anyone else comes into the room.