Abstract: A direct ventilation gas fireplace having co-linear air intake pipe and gas outlet pipe. The pipes are separated from each other so that the fluid flowing in one pipe does not come in contact with the other pipe. The gas outlet pipe may comprise a safety release valve that allows any excess pressure, in case of explosion, to exit through a lateral spring-actuated door into an enclosure closed around the combustion chamber. This safety release valve allows to build fireplaces having pipes longer than the usual length allowed for respecting specific safety tests in case of gas explosion.