Replacing bathroom exhaust fan

Hello, I have a quiet, 6" duct, horizontal discharge bathroom fan to replace the old, loud and malfunctioning 8" vertical discharge fan. What I hadn't realize was that, with the roof cap right above the fan, the exhaust for the old fan was just a 3 ft.-long, vertical 8" air duct. To use the same cap I have to shift the new fan along the joist, cut a new hole, and direct the duct up with a single elbow. Or, alternatively, to reuse the hole, connect three 6" elbows to direct the horizontal discharge into the roof cap above.

I prefer shifting the new fan and cutting a new hole in the ceiling, but this bathroom is tiny (in the photo, the curtain bar is 5 ft), so I can only move the fan even closer towards the heating outlet.



Can a fan be as close as 6" from the heating outlet? Or is it better to bent the air duct with elbows? The roof cap is only 4 feet directly above the fan ceiling hole. Would greatly appreciate any comment! Best Wishes, h.

 

If I were hired to do that job I'd keep it in the same place and use insulated flexible ducting to make the connection.

I was going to mention that metal ducting for a bathroom exhaust fan usually has condensation issues but I'm imagining you're in a year round warm area where the attic doesn't get extremely cold.

 

Thanks, PJmax! I have prepared insulating 6" sleeves for metal ducting. I've heard that metal ducting is quieter and doesn't' collect dust etc. So, just wanted to keep metal ones as it was on the old fan. What flexible ducting would you use? Plastic over a metal spring?

 

If asked my opinion..... I would say metal ducting would be nosier or louder but in the attic it's really a moot point.

 

Yes, doesn't matter that much, and with such a short exhaust. If flexible ducting, is it insulation over a thin plastic sheath with wire?

 

Can you hang the new fan in a vertical orientation?

 

I guess I can't. The intake flow and exhaust flow are perpendicular.

 

Can you provide a link to the installation instructions for the fan?

 

I'm installing Broan QXTE080. Below are the instructions for a similar one in design:

BROAN QTXE080FLT USER MANUAL Pdf Download.