DuraVent 5"x8" DirectVent Pro Adjustable Pipe Length:11" 17" Where should I use the w18.9 Where should I use the Ranger Canada United States Clearance – top (measured from the platform on which the appliance is installed)** 80" 80" Clearance – combustible side mantle to unit 8" 8" Clearance – combustible side wall to unit 13" 13" Clearance – combustible top shelf to unit 58" 58" *The information given on the certification label affixed to the appliance always overrides the information published in any other media (owner's manual select vinyl siding standoff has been tested and listed as a decorative gas appliance system or as a direct vent heater system by a major testing agency