A humidifier is a machine that helps to restore the moisture in your air. By far, you might find that your home seems much more uncomfortable during the winter than in the other months of the year. Largely, this is due to the lack of moisture in the air. Humidifiers are available in a variety of sizes which are able to keep homes, both large and small, more moist during the winter months. Humidifiers may be able to be built into your central heating and cooling system, or your closed heating system to help circulate moisture through your home using either the furnace or fans, respectively.