July 14, 2010 - 6-7 p.m. - Zumwalt Residence tour as part of the Cincinnati State Alternative Energy Sources course - true Geothermal, air ground-cooling tubes, 9008 Decima St., Blue Ash, OH 45242. Joe Davis's site, the current owner, will be giving the tour. His site includes construction and other technical details of the underground home. RSVP to Chuck.Lohre@Green-Cincinnati.com or call 513-260-9025 for more information. There is no charge for the tour. Call if you get lost or are running late. Slideshow.