For indoors, I like to rent these:
http://www.mdgfog.com/pdf/atmosphere-aps-series_e.pdf
Very carefully controlled particle size, below the 1u to 1.5u range where your lungs trap particles excessively. Since its Co2 driven, its not a thermal "cracker" with all the nasty health issues.\
World class machine. The designer had good taste in beer, used to come to laser show conferences.
Steve