Mesas MD-Series Dehumidifiers eliminate moisture & protect valuable items from the irreversible effects of rust and mildew. The MD series are ideal in tightly closed spaces with little to no ventilation; excellent for safe storage. The MD Dehumidifier circulates warm dry air on a 24 hour basis. an enclosure on a 24 hour basis. This increases the temperature of the air several degrees above the ambient outside temperature reducing moisture.