Thomas, this is a Direct Vent Gas Insert that would take the place of your existing coal basket. It is a sealed system and uses two 3" flexible aluminum vents which run the entire length of your chimney with a termination cap installed at the top. Some amount of deconstruction of the original firebox and removal of any obstructions above it leaving to the flue is required. The process is relatively simple for a very experienced installer. Minimum cavity requirements vary a bit depending on the front chosen but the Windsor Arch pictured requires 25 1/4" h × 20" w x 11 1/2" d. Enlarging the available opening is possible in most cases. I've installed many of these over the last 16 years and would be glad to assist with advice. I assume you are not in the South Eastern U.S. The manufacturer is Valor. You can get other information on this unit and available options at www.valorfireplaces.