Better to vent furnace out wall or chimney?
We are getting a new 95% efficient gas furnace and it has been mentioned that there are two options for venting it out of the walk-in, unfinished basement. It could either go out the unused, walled-in chimney that the oil furnace was vented through, or they could cut a hole in the concrete block wall and vent it out the side of the house. The basement ceiling is about 6-1/2 or 7 feet high. If it went out the chimney, it would leave more headroom. Since they say they could do either, which should we choose?