I took several of my crock pots (all different sizes) and set them in different rooms around the house. I used the smaller 1 1/2 - 3 quart ones in the bathrooms and kitchen. I used the 4 - 6 quart ones in the bedrooms and livinng room. I then filled them 3/4's of the way with water, placed the lid on and turned to high. This allowed the water to quickly heat up. After an hour or so I removed the lids and let the moisture start escaping in the air. You want to make sure you keep an eye on these so that they don't run dry. I would suggest not adding cold tap water to them as they need water, but catch some water in pitchers or bowls and let it come to room temperature before adding to the already hot crocks.
crockpotrecipeexchange.com/2012/01/using-your-crock-pot-as-humidifier.html
crockpotrecipeexchange.com/2012/01/using-your-crock-pot-as-humidifier.html
