humidifier demand and the power module 30 need be made and stocked only in a number a significantly lesser number adequate to meet the demand for powered humidifiers substantial advantages economies and costs savings are consequently realized in all stages of the channels of trade from manufacturer to consumer for some hot air furnace humidifier systems and or installations it may prove desirable to provide means for controlling the delivery of water to the evaporator unit or assembly 14 and or for controlling the times and duration of operation and or the speed of operation of the motor driven fan 34 to satisfy this demand the present invention provides another modular unit namely a control module 40 as depicted in fig5 7 and 8 10 the module 40 is comprised of a housing 42 of a size shape configuration and design compatible with and complementary to that of the modules 10 and 30 so that when the same are assembled together as illustrated in fig7 10 they will convey the appearance of a unitary product of pleasing design the control module 40 like the power module 30 is invertible so that it may be assembled onto either the left hand side or the right hand side of the humidifier module housing 12 as may be required in powered humidifier.