Simmering a pot of water on the stove adds humidity to the air without a humidifier. Set the temperature to low to heat the water. Add more water, and adjust the setting as necessary to prevent the pot from boiling dry. Line drying laundry inside the house also increases humidity.
Heating water converts it to a vapor from steam. Placing a pot on the stove is an effective means of increasing humidity. When using the simmering pot method, leave the kitchen vent off so the humidity the pot creates remains inside the house.
Increase humidity in areas away from the kitchen by line drying clothes inside the home. Stretch a clothesline, or purchase a folding drying rack. Wash a load of laundry, and hang it to dry. Hanging laundry to dry reduces energy consumption and adds up to 2 1/2 gallons of water to the air in a home each week. If there is no dirty laundry, run a few towels through the rinse and spin cycle of the washing machine, and hang them to dry.
A lack of humidity is often a problem in the winter when the furnace of heating systems dries the air in the home. The dry air dries occupants' skin and respiratory passages. Increasing the moisture levels in the air provides relief for itchy skin and stuffy noses. While machines are available for the task, they are not always necessary.