Abstract: A gas fireplace is provided having a plenum formed around at least a portion of the fireplace firebox. Room air enters the plenum and is heated by the firebox prior to venting back into the room. Two openings are provided from the outside of the fireplace housing to the plenum. The first opening allows heated air to exit the plenum, while the second opening allows cool outside air to enter the plenum. a mechanism is provided to control the amount of heated air exiting the first opening and the amount of cool air entering the second opening. By controlling the inflow and outflow through the first and second openings, respectively, the amount of the fireplace by-products generated into the room where the fireplace is located such as carbon-monoxide, nitrogen dioxide, heat and moisture are reduced.

Abstract: A gas fireplace is provided having a plenum formed around at least a portion of the fireplace firebox. Room air enters the plenum and is heated by the firebox prior to venting back into the room. Two openings are provided from the outside of the fireplace housing to the plenum. The first opening allows heated air to exit the plenum, while the second opening allows cool outside air to enter the plenum. a mechanism is provided to control the amount of heated air exiting the first opening and the amount of cool air entering the second opening. By controlling the inflow and outflow through the first and second openings, respectively, the amount of the fireplace by-products generated into the room where the fireplace is located such as carbon-monoxide, nitrogen dioxide, heat and moisture are reduced.