Abstract: A humidifying aid has a container having an open top for receiving water or the like. A pair of first and second upstanding arms extend from the container and terminate in a pair of transversely and outwardly extending ears for resting on the rim of an outlet opening for the furnace air recirculation system. Once the humidifying aid is disposed in its position, the grill cover for the outlet is placed over the humidifying aid for concealing the humidifying aid from view, while permitting access to it for replenishing the water supply therein. Thus, needed moisture is added to the recirculating air.