When given a choice of using hot air or paper towel to dry hands for children, use the paper towel. The advantage of using paper towel is that the act of rubbing the paper on the little hands removes a significant number of residual germs left after washing something that is not easily done with hot air as children often do not dry their hands long enough under the hot air to dry all the moisture on their hands. The moisture on their hands then harbors germs.
I know we are all trying to be green and reducing our carbon print wherever we can. Perhaps instead of using lots of paper towels to dry your hands, just take one and tear it on half to dry the hands.