Franklin stove

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A cast-iron heating stove shaped like a fireplace but employing metal baffles to increase its heating efficiency.

from the GNU version of the Collaborative International Dictionary of English.

• A kind of open stove introduced by Benjamin Franklin, the peculiar feature of which was that a current of heated air was directly supplied to the room from an air box; -- now applied to other varieties of open stoves.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A metal-lined fireplace with a hollow baffle and a flue acting as an inverted siphon, intended to produce more heat and less smoke than an ordinary open fireplace.