Ignis Ventless Bio Ethanol Fireplace Ardella with Safety Glass Ventless - no chimney, no gas or electric lines required. Easy or no maintenance required. Easy Installation - Can be mounted directly on the wall or recessed (mounting brackets included). Capacity: 1.5 Liter per Burner. Approximate burn time - 5 - 9 hours per Burner per refill. Approximate BTU output - 6000 per Burner (Total BTU - 18000). Includes Front Tempered Glass Barrier.