Get my ducts in a row, please.

May 18, 2010 10:16 AM

Old frame farmhouse, may or may not have firestops. Old octopus-style gravity furnace has ductwork to first floor only (but has floor registers in upstairs rooms). When installing a new furnace and ductwork in this situation, if upstairs ductwork is desired, where/how does it typically get routed?
posted by bricoleur to Home & Garden (5 answers total)

Typically duct-work to the second floor will be located within framing, furred out walls or mechanical shafts located in out of the way locations such as back of closets.

Collaborate on a design/build solution with a heating/cooling contractor you can communicate with and trust or hire a mechanical engineer.
posted by xod at 10:47 AM on May 18, 2010

Our gravity furnace was replaced by forced air in 2003 (midwestern US) and the supply and return were run exactly as xod states, inside plywood chases installed in the back of closets. It killed off the closets pretty well but was the only realistic choice.
posted by werkzeuger at 11:31 AM on May 18, 2010

Best answer: Moved into 95 year old frame farmhouse three years ago. Replaced aging forced air furnace which had similar ductwork to your house. Found an 18" square space next to the interior chimney which runs from basement to roof. We were able to install a vertical metal duct alongside chimney. It terminates in a distribution box in the attic with insulated flex tubing to ceiling vents in each of the 4 upstairs rooms. It has helped wonderfully with air conditioning!! The upstairs usually is well heated too.
posted by tronec at 12:52 PM on May 18, 2010

You're a step ahead of where we were a year ago; there were no ducts at all upstairs in our old farmhouse. No closets, either.

(No attic, either, otherwise we might have done something similar to what tronec describes.)

Houses of similar vintage in our area have interior corner posts, usually covered with paneling, sometimes just plastered over. Our house wasn't constructed that way. But, since it might have been, we faked it. We boxed in the corners of our parlor with 6 inch "posts." Inside those boxes? HVAC ducts, air returns, and in one corner, plumbing for the upstairs bathroom.

Memail me if you'd like pictures.
posted by minervous at 1:59 PM on May 18, 2010

Response by poster: Thank you, all good answers but tronec's solution fits my house perfectly.
posted by bricoleur at 10:35 AM on May 20, 2010