I've been scouring posts dating back to 2005 and have not found an answer to my current issue.
I have a brand new home that has a Heat n Glo SL-550 direct venting fireplace. It is installed in an insulated bump out which has been properly insulated in all 6 spots(even spray insulation underneath the sheeting from the basement). This unit is configured to use the Intellifire system so it does not have a steady pilot on.
My issue is that when the fireplace is not in use, it is convecting cold through the combustion air pipe which cools off the the bottom of the fireplace and creates a cold spot in my living room. While my hairy fluffy dog loves it, us humans don't so much. I've had the service tech from the company who installed the fireplace come out and was told nothing is wrong and it's the nature of the design. I've taped up all knockouts for the gas line and electrical and any other open spots with foil tape to minimize any cold air infiltration.
My folks live down the road and have a Vermont Castings DV. Their fireplace is installed in a corner configuration and has a bit more piping(elbows, length, etc) and a different termination cap and there is no cold convection issue at all. Their knockouts are actually wide open.
So long story short, is there anything I can do to stop the cold besides installing a always on pilot to counter the cold effect?