A new diffuser for essential oils and the like is rendered more compact by integrating the entire diffuser into a form of cap threaded to fit a bottle operating as a reservoir. The motor and pump system are integrated into a package sleeved inside a housing that then receives in a silo beside the pump and motor the entire reservoir and diffuser system. Simplified control algorithms provide a limited set of buttons that are more intuitive by which a user need only define total time of operation, some level of intensity of scent, and an indication of the comparative size of the space to be conditioned by the diffused scent.
