Does my chimney have to be lined?
A traditional fire with a large opening looks beautiful, but it is not efficient. The air across the opening has to move towards the fire and up the chimney to avoid dangerous fumes coming into the room. It is obvious, therefore, that the larger the opening, the larger the size of the flue required to carry the volume of air up and out of the chimney. This massive volume of air has to rise up by being heated by the fire and hence the phrase we hear so often in our business, “all the heat goes up the chimney”.
Most open fronted fires, whether coal, wood or gas, do not require the chimney to be lined unless there is a problem with the chimney. Open basket fires are very inefficient but a modern high efficiency box fire can achieve up to about 60% efficiency.
Most glass fronted fires or stoves are more efficient. They are designed so that the heat goes into the room rather than up the chimney. They can only do this if the volume of air, that needs to be heated in order to expel the fumes of combustion up the chimney, is reduced by installing a liner in the chimney. Some modern homes have well insulated pot glazed flues that act in the same way and can be connected by an adaptor to the fire so that a liner is not required.
There are exceptions, but for most houses and most fires, the rule is that an open fronted fire will not require a liner, but a glass fronted fire will.
