The average homes relative humidity level during the dry winter months can be as low as 13%. This is lower than the relative humidity of the Sahara desert. With the humidity level this low you or one of your family members will suffer through the winter with dry sinuses, this can lead to an increase in flu and colds. The wood in your furniture and floor can crack.
You can improve the overall humidity in your home by adding a humidifier to your heating system. Bring moisture back into your home and the whole house will be feeling better.
Most systems now use a water panel format. This allows the water vapor to be pulled into your supply air while your furnace is running; the overflow water is carried out to a drain.