No.Per the sizing tables, all orientations must terminate vertically with a UL listed rain cap, otherwise the appliance may not vent properly. However, sometimes it is permissible to vent a Category 1 appliance horizontally with B-vent if a certified flue gas exhaust fan (Exhausto, Tjerlund, Field Controls) is mounted on the exterior wall to pull the flue gases out.
Can B-vent terminate horizontally?
    April 1, 2013
		            No. Per the sizing tables, all orientations must terminate vertically with a UL listed rain cap, otherwise the appliance may not vent properly.
 
         
            


