by Scott Atkins
When considering one of the gasfireplaces it is important to decide which type of venting system you will be using. There are three different venting systems that can be used with the natural gas fireplaces or the propane gas fireplaces. None of the venting systems for the gas fireplaces will use the standard, large chimney that is used with the wood burning fireplaces.
Shielded, what sorts of life are stirring yet:
Legs lagged like drains, slippers soft as fungus,
The gas and grate, the old cold sour grey bed.
—Philip Larkin (1922–1986)
The gas fireplaces direct vent system will use the system that will draw in fresh air from outside. This will be used in the combustion process. The by products are removed to the outside. No air is used from the room or released into to room. This specialized system is a coaxial pipe or a pipe in pipe design. While the outer pipe brings in fresh air, the center will expel the by products. As the cooler, fresh surrounds the warmer, used air, this will help to heat the fresh air making this a very efficient process.
Another venting option is the B-vent of the natural system. The fireplace will draw the fresh air from the room to be used for the combustion process. The used air and all of the by products will be removed by a vent that is terminated above the roof line, like the furnace. This is more decorative but it will lower the efficiencies of the gas heater.
The ventless gas fireplaces are really vent free. This system will pull in air for the combustion from the room. The combustion process will take place and that same air is returned to the room. For safety purposes, a system to monitor the oxygen level of the room has been designed. This system is called the Oxygen Depletion System or the ODS. If the oxygen level in the room drops by 2% the system will shut down the fireplace. While some of the major manufactures will not develop the vent free gas fireplaces, others stand by the record they are very safe. A few states will not allow the ventless gas fireplaces, others will allow with a permit only. Most states will allow the vent lees with no conditions.
The gas fireplaces offer the great ambiance of a fireplace with the great advantage of not having to deal with the burden of the wood. Some owners of the wood burning fireplaces will choose not to use their fireplaces because of the hassles involved with the wood and the cleaning of the ashes. And do not forget to use some of the many gas fireplace accessories to really give the fireplaces a great look and feel. If you will be using either the B-vent system or the gas fireplace direct vent you will be using a vent pipe. If you decide on the ventless gas fireplace, there is no need for any venting system. A gas fireplace will add a great look to any room. With the many different options for the gas fireplace vent systems, there is something for almost every room.