Fireplace inserts have changed dramatically since they were first introduced. New technology and tighter standards have improved their ability to burn wood and also protect the environment.
The Environmental Protection Agency certifies fireplace inserts as either catalytic or noncatalytic. Catalytic inserts ensure that virtually all harmful portions of the woodsmoke are removed prior to releasing it into the air. Although more expensive, they allow the owner to burn wood at a lower temperature for a longer time, which gives an extended heating period with less wood.
Another type of wood burning stove that uses an existing fireplace sits right in front of the fireplace as a separate unit. The smoke and fumes are directed into the fireplace flue through a modified vent.
Fireplace inserts require wood that is a little shorter than the normal 18-inch size for fireplaces. Often a 16-inch length works much better. An insert owner should always look to ensure he gets the proper length when buying wood in bulk. Otherwise the wood will need to be cut again.