The most important part of either an outdoor or indoor fireplace is the chimney, which vents the hazardous and noxious gases that are produced by burning of fuel.  Fireplace chimneys regulate the airflow, thus keeping excessive heat from igniting any combustible materials near and around the fireplace. 

Originally, chimneys were constructed out of brick or stone and mortar and lined with fireproof tiles.  Today, however, there are models of metal, which are very simple to install.  Whether the chimney is constructed from brick, stone, or metal they have to be able to withstand the constant heating and cooling as well as the corrosive compounds produced by the fire.  

The flue is a pipe, tube, or channel that carries the hot air, gas, and smoke from the fireplace or stove to the chimney, making the flue the most important layer of fireplace chimneys.  If burning wood, creosote, which is a highly flammable substance, can be deposited on the flue, and can restrict and even block the flow of air through the system, which can create chimney fires.  Therefore, a clean flue is vital for a fireplace to function properly. 

Other components of the fireplace chimney include the chimney cap, chimney flashing, chimney damper, chimney liner, and cleanout door.  Chimney caps are usually constructed from copper, or stainless steel and function as the chimney cover, which prevents downdrafts as well as protecting the chimney from the elements and keeping animals from getting into the chimney.  The chimney dampers close off the fireplace chimney when you are not using the fireplace.  Flashing prevents rain from seeping between the chimney and the roof.  Chimney liners can be made from stainless steel, cast-in place, aluminum, or terracotta and help to improve the performance of the fireplace chimney.  Cleanout doors are found at the base of the fireplace chimney and makes cleaning the ash pit easier.

How the chimney is designed as well as its size can affect how the fireplace draws or performs.  Proper size and height is needed to ensure that the smoke is pulled up the chimney and for the proper burning of wood.   

Proper maintenance is needed in order to avoid the risk of chimney fires.  Every year you should have your chimney inspected and cleaned to ensure that it will work correctly and to ensure the safety of your family and friends.  By properly maintaining your chimney, will ensure you many years of enjoyment.