Christian Fox posted for all of us...
I don't top post - see either inline or at bottom.

Hi,

I'm planning on getting a high-efficiency natural gas-fired furnace to replace our
current 15-year old standard-efficiency furnace within the next year or so.

I've heard that the high-efficiency furnaces require different ducting, and use a vent on
the side of the house rather than a chimney as an exhaust.

Our current furnace has two insulated ducts going to the side of the house, and the
chimney running to the roof. If I get a new high-efficiency furnace, is it likely that
the ducts to the wall will need to be changed?

The reason I ask is that I'm considering finishing my basement, and if I do the ducts
won't be easily accessible. If the ductwork will need to get changed or replaced, I'd
rather do that before finishing the basement ceiling.

Thanks in advance for your help!

Christian Fox

Maybe... and you're welcome
--
My boss said I was dumb and apathetic.
I said I don't know and I don't care...

Tekkie