If you want to root some varieties of fruit, it requires high humidity, and bottom heat, without excessive air temperatures. I have come up with the following set ups to help raise the humidity, within a humidty chamber, without raising the air temperature.
This is for late winter rooting in your baseemnt, away from the sun
Clay pot method:
Take a clay pot and plug the bottom hole. Fill the pot with water and place it in the humidity chamber. You will then need an aquarium air pump, air tubing and a small airstone. Plug the tubing into the air pump, and the other end into the airstone. Put the airstone into the water pot and plug in the pump. This should raise the humidty to 60% within a chamber 3'x2'x18".
Take a good size jar and punch two holes in the lid for aquarium air tubing to pass through. Place tubing through holes as shown in the below diagram and seal the tubes in place with silicone rubber cememt. Fill the jar with water, plug in the pump, and you can deliver cool humid air to the humidity chamber.
I hope this is useful to those not wanting (or able) to set up a misting system in their basement.
Hardiness Zone 6a