Despite the increased availability of ventless gas fireplaces, traditional gas fireplaces require an efficient flue or vent system. If a vent or flue is inefficient, that can lead to the erosion of mortar joints, causing potentially dangerous fumes and tars to escape. It also boosts the build-up of soot, thus increasing the risk of fire.
Although not necessary with outdoor gas fireplaces, all new chimneys now have to be built with a vent or flue lining to protect from harmful flue gases. The lining is usually made of refractory concrete or impervious clay. It has long been realised that a vent or flue lining improves the flow of combustion gases, and it was not unusual for old vents or flues to be lined with lime mortar as the chimney was built. However many were not lined at all.
A modern vent or flue liner can replace perished lining in a chimney, reduce the size of the vent or flue in order to make the gas fireplace more efficient, or add stability to a frail chimney structure. A specialist installer or manufacturer such as Houston gas fireplaces will advise you about the most suitable and cost effective type of liner for your direct vent gas fireplace.
Be it gas log fireplaces or gas insert fireplaces, for the most efficient gas fireplaces, use must be made of a rigid sectional liner for your vent or flue. This type of liner, which may be made of ceramic, lightweight pummice or refractory concrete is well established because of its durability, and is commonly used for new installations. They are suitable for all types of fuel.
A more recent innovation for the lining of old chimneys of gas fireplaces is the use of a lightweight concrete that is pumped into the vent or flue around an inflatable tube. The concrete is specially formulated to provide a fire-resistant insulative lining that seals the old brickwork while reinforcing the structure. However if your gas fireplace is multi-vented then another approach is preferable.
When looking at cheap gas fireplaces and vented gas fireplaces, flexible stainless steel liners are the simplest and cheapest to install. Particularly used in association with corner vented gas fireplaces the best of these is the spirally-wound double skinned type. Made of austenitic stainless steel, which is particularly resistant to corrosion as well as heat, it has a smooth inner surface, and can be used for gas fireplaces, freestanding gas fireplaces, and appliances that burn coal, wood and oil. Made as a continuous length, it can be fitted easily to both straight and offset vents or flues. Single skin flexible steel liners are usually designed for use with gas fired boilers or room heaters only. They should never be used with solid fuel or wood burning fires or stoves.
In conclusion if you are not using a vent free gas fireplace, it is essential that your vent or flue is in prime condition, especially when used in conjunction with natural gas fireplaces such as those made by Majestic gas fireplaces. For the best information always consult your local gas fireplace wholesalers for details and vent requirements of cheap gas fireplaces.
