The majority of projects so far are for the gaming and hospitality industries, where there is a high return on investment in systems which create and maintain high quality air. It has been found that ozone works well with par- ticulate filters. It eliminates the need for costly carbon VOC filters and re- duces the makeup air required which is costly to condition. Paybacks for ozone systems are typically about one year, and facilities customers and managements are very pleased with the noticeably higher air quality. This paper will present data from a bingo hall in Washington.