Vent-Free Gas Log Fireplaces
Unvented gas log fireplaces
When you go shopping for gas fireplaces, you'll find that some gas logs are not vented. 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. Byproducts of combustion simply enter the living space.
Unvented gas logs can be placed in a masonry fireplace, or in special fireboxes made to resemble a hearth.
Unvented gas appliances are always equipped with an Oxygen Depletion Sensor (ODS), which kicks the fuel source off before carbon monoxide reaches a dangerous level in the room.
Water is a byproduct of combustion. In a vented appliance, most moisture escapes out the vent, but in an unvented unit it enters the living space. The extra humidity can be a plus for many homes during dry winter months, but if your home is tightly insulated the excess moisture may condense on cold windows.
Follow a Few Rules
- Unvented gas fireplace appliances generate a lot of heat, so combustibles must be kept at a safe distance. Fireplace doors should be left open during use.
- Never go to sleep and leave unvented gas logs burning. Most manufacturers recommend you only burn the logs for a few hours at a time.
- Open a window slightly while the gas logs are burning, to let fresh air enter the room.
- Bigger is not always better. For best air quality, the gas fireplace unit you install should be approved for the size of the room it will be used in.
- Unvented gas appliances are not legal in all areas, so check your local building codes before buying a unit.
It's a good idea to install one or more carbon monoxide detectors, no matter what type of fuel-burning appliance you might have. Detectors are an inexpensive way to put your mind at ease about the air quality inside your home.