Yes. They retain heat to radiate back into the room. They also act as a barrier to protect your firebricks and masonry from over exposure to the direct flame.
The wood fireplace goes back thousands of years and no one knows who invented it. Benjamin Franklin invented a particular kind of stove (not a fireplace) that was more effective and efficient than a fireplace in warming a room and in fuel consumption. The Franklin Stove was also easier and safer to use for cooking than a fireplace was.
Often the most efficient way to do this is to buy an insert for your wood burning fireplace. There are many professional companies who can do this and ensure that the job is done correctly.
Better, in a heat efficient way, because there is no loss of heat, with a real one,you need to vent exhaust fumes and at the same time you lose heat. A real fireplace looks better but is less efficient.
A hob is a shelf at the side or back of a fireplace.
In general, a standard fireplace is not the most efficient method of heating your home. A substantial amount of the heat produced is lost up the chimney. Depending on your local regulations, an efficient wood stove or fireplace insert would be a better choice.Always consult with a local qualified expert before installing any heating system.
A firebox is the area within a fireplace where the fire is built and contained, while a fireplace insert is a self-contained unit that is placed inside an existing fireplace to improve its efficiency. Fireplace inserts are typically more energy-efficient and provide better heat output compared to a traditional firebox.
Ask This Old House - 2002 Installing Home Intercom System Energy-Efficient Fireplace 8-2 was released on: USA: October 2009
Stegosaurus had plates down it's back
chimney
will snow cause my fireplace to have a back draft?
Wood-fueled heat, however, is relatively inefficient and emits more pollution than oil, gas, or LP. A standard fireplace, for instance, is only 5 to 15 percent energy efficient.
It's called a rack.