I have a house about 6 years old with central heat and air. The heat
is propane. The unit is in the crawl space.

I have seen those humidifers that add humidity to the house in winter.
I live in Kentucky. (Almost in Tennessee). Do these things work well?
I have heard they let you run your thermostat a little lower. I also
read they can use 18 gallons of water a day which would add to the
water bill.

My main concern is I have a newborn and supposedly keeping a high
humidity level in your house makes it less likely for people to get
sick and decreases respiratory problems along with keeping you skin
from drying out.

Is it bad to have too much humidity inside? Do they make a
humidifer/dehumidifer for the whole house? What this be beneficial?
ANy advice is greatly appreciated!