Fireplace Inserts are an easy and effecient way to increase a fireplace's heating abilites and also creating a more aesthetic appeal. Most fireplace inserts have self-cleaning doors, so you can enjoy the view of flames in the fireplace while the doors are closed, making the fire more efficient. Manufacturers also add utility features to their inserts, such as fans and thermostatic controles depending on the fuel type.
Typically, air enters through a vent in the insert, heats up while circulating around the main chamber, and exits through another vent. Fireplace Inserts are catagorized by the fuel burned for operation (Natural gas, Propane, EPA-certified wood, Pellet).