We are thinking of installing a double sided direct vent fireplace on the main floor, dividing the dining room and living room. The fireplace will be approximately 10ft away from an exterior wall.

Initially, I have always think of having the vent run vertical ~7ft to ceiling joist space and then horizontal 10ft to exterior wall. Upon visiting to a fireplace store, the person there raised a question for running horizontal 10ft may not be doable. But after reading a couple installation manuals, the 10ft horiz. run seems possible the those brands.

Today, when my wife was talking to her coworker, she also raised the questions for the horizontal run. The co-worker has gone thru a few renovation herself, but no expect.

I'm still in the planning stage for layout, just want to ask some expert here to confirm that the fireplace location can be vented horizontally 10ft with 7ft vertical run. I would much prefer this route and not having the vent vertically all through my second floor to the roof.

Thanks!