Questions about ventilation or if the space will even work.

Have an existing safe room/ vault room in my house I am wanting to turn into a root cellar. It is roughly 7’wx16’lx8.5’h the entire thing is constructed from 8” concrete walls including the ceiling. I assume the floor is your typical 4”. Two of the walls are against dirt and the others butt up to my finished basement. It stays about 60 degrees at the moment but that is with an interior door ant the entrance and my basement is heated and cooled. My thought was to put an insulated exterior door at the entrance to help keep the cold in. My problem is the ventilation. I can’t go through my finished side without a huge mess and cost. Was wondering if I could do vents up high for both cold air intake and gas venting. I have power in the room and could power vent both the cold air intake and gas vent. Wanting feed back to know if this will even work. Also live in Missouri. So winters stay cool. I can upload pictures to give a better visual if necessary.Thanks

I'm jealous that you have such a space! Storage is low on my property but lets get to the nuts and bolts.

You can not go through the outside finished wall, but you were wondering if you can go high. Do you mean venting to the first floor?

I know you want to have roughly a 6" intake and outtake as like a basic idea.

I guess my question is can I have both the intake and exhaust vents come from the ceiling if I power vent them. And will 3 or 4 inch pipe work rather than the 6”. For what I’m thinking 6” might be too big.

The diameter of the pipe changes the speed of the air for a given volume per hour of volume change.
The inlet pipe may be best to bring down close to the floor and the outlet pipe keep neaqr the ceiling at the other end of the room to ensure as much movement of air as possible.

Hey,  welcome to Permies!
Core drilling through 8" of concrete takes some special equipment.
If you have a standard 80" high doorway, you could lower the header by 8" , giving you that space to run your ducting through and your doorway would still be six feet tall.
If you run 4" diameter intake ductwork through the center of your 6" exhaust ductwork,  you will insulate the intake from the warmth of the home, cutting down on condensation.
It will also mean youe will not need to makes as many holes in studs, insulation,  siding,  etc.