Steam from kettle

[justlead1]

Hi One of my nipper has a cafe, In order to make a presents i would like to hang a large kettle at high level outside the cafe, that will emit steam. (not unique as the Blue Kettle at the Angel Islington had the same some 50 years ago.Hence the idea, But not around to ask.)
Other than stoking with dry ice on a regular basic, what other methods can i consider to achieve my aim?