Abstract: A humidifier for a hot air furnace is disclosed which has a housing with at least one open outlet to allow steam to enter the furnace. The housing also contains a heating device, water refill pipe and water level sensors and sensor housing. The sensors are preferably flexible wire with one end being free to flex. The housing also contains a water vessel attachment area which interacts with a housing attachment area to secure a water vessel to the housing. The water vessel contains a liner which has an integral flange around the periphery of the open end to form a gasket between the water vessel and housing. The housing attachment preferably contains at least one water seal which comes in contact with a flange and prevents steam from escaping the humidifier. Handles can be provided on the vessel to allow a user to easily rotate the vessel. A second open outlet can be provided to allow steam to enter the furnace through a moist air duct.

Abstract: A humidifier for use with a hot air furnace has an upper and lower housing removably connected to one another. The upper housing has a heating element and sensor, water refill inlet, and a control circuit connected to the heat sensor and inlet. The lower housing contains a water vessel and a water level sensor secured the lower housing to receive the water vessel. The water sensor registers the minimum and maximum water weight and is connected to the control circuit. A bacteria resistant, semi-flexible removable liner fits within the vessel for the removal of built up mineral residue. Preferably the water sensor is an elliptical beam load cell with an open center surrounded by a rim and a pair of tab ends opposite one another. At least one bridge is machined within the rim to increase sensitivity. A strain gage registers strain changes and an electronic connector transfers the changes to the control circuit where they are converted to the current weight.

Abstract: A hot air furnace humidifier has a heat chamber and a duct connecting the chamber to a furnace. The chamber has a water retaining vessel, preferable provided with a disposable liner. A pair of level sensors register the minimum and maximum water level within the vessel. The water level sensors can be either in proximity with the water or submerged within the water. A heating element incorporates a heat sensing device and can be provided with a thermostat and in proximity with the water or submerged. A water refill pipe is provided with an on/off device and automatically refills the vessel in response to the electronic controls. The electronic controls are connected to the water level sensors, heating element and water refill pipe. The controls can include a humidistat and/or be incorporated with the furnace controls.