The American Standard^® EHUMD500 humidifier is a fan-powered unit that adds the right amount of moisture in every room, with a capacity of 18 gallons per day and up to 4,200 square feet. Temperature is just one factor in total home comfort, especially in dry weather. American Standard trusted humidifiers can protect your wood floors and furnishings from drying out in the winter, can help alleviate allergy symptoms, improve comfort, and save energy by lowering the thermostat temperature.