An enclosure defines a confined space configured to store goods that can be advantageously maintained by controlling the water vapor levels to which the goods are exposed. A water vapor conversion element, at which liquid water is converted to water vapor, can be operably associated with the confined space to distribute that water vapor to the confined space. A water delivery unit is operatively associated with the water vapor conversion element and is configured to deliver water in liquid form to the water vapor conversion element. The water delivery unit can comprise a drip chamber configured to deliver the water essentially one drop at a time. The enclosure can comprise a drawer in a refrigeration appliance such as a household refrigerator. A sensor configured to determine the water vapor level present in the confined space can be operable to selectively control the distribution of water vapor to the confined space.