An evaporative cooler having an evaporation pad shaped to extend essentially circularly about a blower to define an essentially circular chamber into which the blower draws air through the pad to evaporate moisture therefrom. The chamber may have oppositely convex top and bottom walls, with the blower preferably discharging downwardly through the bottom wall. Water is fed to the top of the pad through a tube extending circularly along the upper edge of the pad and containing water under pressure and having spaced openings through which the water discharges onto the pad.

A humidifier including a base enclosure defining a reservoir to be filled with liquid, an opening disposed above the reservoir, and a discharge orifice communicating therewith; a humidification unit mounted on the base, covering the opening and adapted to produce dispersion of liquid retained by the reservoir; the humidification unit being separable from the base along a joint extending around the opening; and a seal mechanism including a channel for receiving liquid disposed to form a seal preventing the passage through the joint of liquid dispersed by the humidification unit. This arrangement provides a vapor seal for power units that expel vapor through a distinct discharge orifice.

An improved reliable easily installed and maintained humidifier and draft control that is installed on a common ceiling mounted forced air duct output register and has an easily replaced and maintained water bowl and fan mounted above the water bowl that has radially extending fan blades about an axle in the center of the fan that rotates when air is discharged from the register and the air is directed to facilitate air movement that assures evaporation of the liquid placed in the bowl and the fan blades may be shaped to direct the flow in a predetermined manner.

A humidifier comprising a bucket housing, a fan for producing a flow of air between an inlet port and an outlet port defined by the humidifier, a motor having a shaft disposed within the humidifier, and an impeller assembly coupled to the shaft of the motor, the impeller assembly comprising a hollow stem extending into the bucket housing and having longitudinal ribs disposed within the stem, and a disk disposed on an upper end of the stem, the disk defining an inner annular shoulder, an outer annular shoulder, a circumferential edge and a plurality of circumferentially spaced apertures disposed between the inner and outer annular shoulders.