In respond to to your dilemma about ducting, it would not have ducting but if you need it it is possible to slip 250mm ducting in excess of the motor housing and repair with tape. Just had it mounted these days and am quite satisfied. They vented the air outside http://angelonmgtg.aioblogs.com/12958426/5-tips-about-diy-sub-floor-ventilation-you-can-use-today