Exhaust fan controller

Abstract

The invention makes the decision to turn on the exhaust fan and dry out the confined space in the event that a factory predetermined moisture level has been exceeded, thereby limiting any destruction or health risks caused by negligence on the part of users or infrequent maintenance. Periodic Maintenance schedules are often extended so far as to be ineffective in moisture control. The invention takes the option to turn off the exhaust fan out of users control but not the option to turn it on. The invention is manufactured in such a way that all electronic components, sensor and pc board mounting fit into any ordinary switch box in a building electrical system and wire directly into the already installed wiring for the manual switch which it will replace.

1 . The invention provides an economical and practical means to detect and exhaust moisture vapor from indoor spaces. In checking 20,912 patents offered by the USPTO website none were found to address or to be aimed at detecting and exhausting moisture vapor automatically from indoor spaces, as this invention provides. There is on the market a manually adjusttable humidity sensor, requiring and/or allowing the user to determine if or when the exhaust fan motor motor will be switched on. Our invention is wholly dissimular in three major ways. First, ours is not based on sensing humitity, but the more direct moisture or condensation sensing. Second, our invention is trully automatic and does not allow users the option of turning the fan motor off, but only to turn it on. The third major difference is the adapability of the various means our circuits offer to different room and electrical installations to accomplish condensation sensing and fan control. 
 In the detail show in  FIG. 3A  the vent fan controller is configured to be installed as a direct replacement of an ordinary fan motor control switch.    The configuration in  FIG. 3B  takes advantage of the flexability allowed in new installations, as this allows the exhaust fan and the controller to be mounted on the ceiling of the subject room and permanently wired there before the room walls are installed.      FIG. 4  depicts a configuration that would mount on the ceiling of larger rooms, possibly in multiples, and using only the sensor, signal conditioning circuit and a minature radio frequency transmitter, would become the monitor of moisture vapor events from the more ideal location on the ceiling. Upon triggering this unit would send a radio frequency “moisture present” signal to a wall mounted reciever, timer and triac controller which would turn on the vent fan motor or motors in the case of multiple installations.    Each of these different adaptations of the basic invention are necessary in certain indoor situtations, but it should be noted that all of them could utilize either the small gold tined fork sensor of  FIG. 1  or the sensor found in any generic smoke detector interchanably if each sensor is given its suitable signal conditioning circuit.