A vent-free fireplace has no exhaust vent. The gas is simply connected to the unit and the flame burns inside without a vent. The blue flame of a vent-free gas fireplace unit is designed to provide nearly complete fuel combustion, resulting in less carbon monoxide and soot than a vented model. Since they do not require a chimney, the heat produced stays in the home. For this reason, this is an excellent choice for those looking for heat and cost efficiency.

The vent-free fireplace are commonly known as Oxygen Depletion Sensor(ODS). When oxygen levels drop, the ODS goes to work by cutting off the flame. With a vent-free fireplace, the damper does not have to stay open whereas with a direct vent fireplace it does. The vent-free fireplaces can be installed even in compact space and the ideal design adds to any decor. Thermostatically controlled heat delivers warmth throughout the room. The gas in these fireplaces burns cleanly, efficiently and costs less to use than wood or electricity.