Heater uses a built-in electric high velocity fan to pull cool air into the rear of the heater, across a heat exchanger, then forces warm air into the surrounding areas. Requires 115V AC power and can be vented vertically or horizontally (please check local codes and restrictions). Low Profile Design - can be installed in low-ceiling buildings. Minimum 8 Ft. clearance from floor to base of heater required with a mounting clearance of 1 In. Spark ignition features self-diagnostic control module. CSA certified. Power exhaust allows for Category 1 vertical or Category 3 horizontal venting (3 In. vertical and 4 In. horizontal vent kit sold separately). 1/2 In. gas connection.