Two combustion vents?

[Kgaalaas]

I’m trying to clear space between joists in my basement for other utility routes and I discovered what appears to be a second combustion vent. The first begins near the floor next to the furnace as I would expect (photo 1) and then runs to the exterior of the house. The second begins at the ceiling of the basement between joists just 3 joists over from the other vent. This also runs to the exterior of the house. Are both of these needed, or is one a relic from when perhaps the furnace was moved? The house was built in ‘96. I am second owner (2011-present) and I have not had any new duct work done.

 

[Kgaalaas]

I’m trying to clear space between joists in my basement for other utility routes and I discovered what appears to be a second combustion vent. The first begins near the floor next to the furnace as I would expect (photo 1) and then runs to the exterior of the house. The second begins at the ceiling of the basement between joists just 3 joists over from the other vent. This also runs to the exterior of the house. Are both of these needed, or is one a relic from when perhaps the furnace was moved? The house was built in ‘96. I am second owner (2011-present) and I have not had any new duct work done.

Never mind. I found my own answer. The second vent is indeed needed.