On Feb 10, 10:43*am, "Bob F" wrote:

A couple elbows shouldn't matter unless you have a lot of piping getting there.

Like 12 to 14 feet? The furnace is not against an external wall.
It's in an interior room surrounded by a basement addition. The
intake and exhaust pipes run about a dozen feet or so across the
basement ceiling before breaking through an external wall. Still okay
to add some extension and a few elbows outside?