In an apartment that uses a gas-with-gas stove (cooking and heating)
and there's a pipe exiting the heater part of the stove and going to a
chimney that's to the right of it. Gas-with-gas stoves haven't been
manufactured for awhile, but that kitchen would still need heat. A
modern gas wall furnace would fill the bill if a new gas stove was put
in, but I have a question about the venting for the wall unit. It
seems they use a concentric pipe that goes through the wall to the
outside providing combustion air and burned gas exhaust. The only
practical place to hang this furnace would be on the wall right next
to the stove where the chimney for the old stove is. So to get to the
outside of the building, you have to go through the wall into the
chimney then through the chimney on the other side to the outside
wall.
Would such a long run defeat the purpose of the concentric pipe?