Setup, current natural gas furnace for the first floor is in a closet on an outside wall of a finished basement (basement has it's own separate system). Due to the slope of the land outside, any lines going to the outside must be run parallel to the wall for about 8 feet before turning and going outside.
One of the salesmen that I've had come out mentioned the need for two lines running to the outside of the house for the furnace, one line for intake of combustion air, the other for the exhaust. In talking to another salesman, he said his plan is to only run an exhaust line to the outside. He's planning on running a 2" intake line from furnace into the main part of the finished basement and pull the combustion air from there.
The current 12 year old furnace is sitting behind a louvered door and therefore is actually pulling combustion air from the basement, but it seems like the second salesman is trying to cut corners by running the intake line a couple of feet into the basement rather than outside. What would you guys recommend in this situation?