- Ventless fireplaces burn efficiently and produce very little carbon monoxide. Emissions produced by a ventless fireplace can be compared to that of a four-burner gas stove. As an extra safety measure, ventless gas fireplaces are equipped with oxygen-depletion sensors that shut off the gas supply to the fireplace if oxygen levels are diluted too much by carbon monoxide.
- Skeptics of ventless gas fireplaces maintain that these appliances emit not just carbon monoxide, but carbon dioxide, nitrogen oxides and water vapor that could promote mold growth into the indoor air. Safety devices are not guarantees, as mechanical errors can happen, especially on aged appliances that have not been properly maintained or inspected on a regular basis.
- Consumers of ventless gas fireplaces can take precautions to ensure the quality and safety of indoor air during operation. If you choose to have a ventless fireplace, have it installed by a professional. Buy the right sized fireplace for the space you want to heat. Do not burn a ventless fireplace for more than four hours a day. Finally, no matter which kind of gas fireplace you install, consider having carbon monoxide detectors in your home to protect yourself and your family.