Direct Vent Gas Fireplaces.
Continental's Direct Vent Gas or Propane Fireplaces do not require a chimney and can be vented directly through a wall or roof. The direct vent draws its combustion air from outside while venting to the same outside atmosphere.
Direct Vent Fireplaces have a completely enclosed chamber that is extremely efficient, drawing in air for combustion from the outside and expelling gases to the outside as well. Direct Vent Fireplaces have a porous front glass enclosure that allows radiant heat to pass into the room.
Safety. ... As another safety measure, the vent pipe can be installed through the wall with a fire-caulked flange. Efficiency. Direct vent fireplaces burn natural gas or propane like traditional fireplaces; however, they convert most of the fuel to usable heat.