Looking to get more heat from the Osburn Horizon zero clearance fireplace? Install the Warm Air Circulating Grille and you'll get just that. There are no moving parts. The grill will use the radiant heat from inside the chase to push warm air into the room. Install the intake grille on one side of the chase close to the floor and install the top grille over the top of the fireplace. Natural convection will create a draw and push warm air into the room. For optimal air circulation, position the grille on one of the fireplace enclosure sides. The grille can also be installed on the enclosure’s front wall, but the air circulation will be reduced.