Abstract: A room security system has a deterrent sprayer positioned on a ceiling of a room selectively inward and in front of an entryway to the room. A spray nozzle of the deterrent sprayer is directed at nose height of an average or anticipated person and adjustable to diverge conically to about three-to-six feet in diameter at a point of contact with the person after partial entry through the entryway. A position slightly on an open side of the entryway can be selected on a ceiling for an entryway with a closure that opens on side hinges like a conventional door. A position directly in front of the entryway can be selected for an entryway with a closure that slides vertically or horizontally like some windows and doors. A trip of the deterrent sprayer and/or other security devices can be actuated and an actuation signal transmitted by mechanical, electrical, electronic, light, magnetic or gaseous means in working relationship with the closure and the entryway.