The chimney in my old house was knocked down and only the firebox remains. Can I install vent-free gas logs?
Technically, the answer is no. Even vent-free gas logs require a chimney to be present, except in specially made vent-free zero clearance boxes. Occasionally you may find a building inspector who will specify construction of a masonry firebox and allow this, but do so only with his careful supervision; this installation won’t be advised by the appliance manufacturer.