Lifesmart EZcool Duo Port Indoor/Outdoor Portable Air Cooler for 500 Sq Feet Maximum Coverage: up to 500 sq ft Uses less energy than a 60 watt bulb Low voltage (12v) is ideal for outdoor use - deck, patio or porch, tailgating, boat, or camping Water reservoir base holds 1 gallon of water for up to 7+ hours of use No pads to clean or chemical treatment. Air and water filters are designed to protect the atomization system and do not require regular replacement