I'm currently reinsulating my attic and found that the exhaust duct for my range hood was not properly connected—it was just loose and sitting on top of the cabinet! The range hood itself is installed under a cabinet with a designated area for exhaust, but whoever did the installation didn't actually connect the hood's exhaust to any ducting. There's about an entire foot of gap between the hood's exhaust and the round duct in the attic, so when the fan is on, it doesn't create any pressure in the duct, rendering it ineffective.
Because of this, I've realized I need to install a rectangular duct properly. I'm wondering if I can simply slide this duct over the exhaust port of the range hood, or do I need to take the range hood down to install the duct first? Also, I'm concerned about how to seal the connection since I can't access the area behind the wall easily. Finally, can I use the same support straps for the rectangular duct as I would for a round duct?
2 Answers
For your situation, it’s definitely best to foil tape the duct to the exhaust port. It might be tricky to do it without opening the wall to gain access, though. If the duct’s dimensions are right, you might need to flare the end to make it fit snugly over the range hood’s exhaust port. Supporting it with some steel plumber's tape secured to the ceiling joists could work well too. Just ensure it's secure enough to handle the airflow!
If you can’t foil tape, duct mastic could be a good alternative to create a tighter seal, especially since you might not have great access.
I think you could set up a 3ft duct from the attic and lower the range hood using a scissor jack for easier access! With some tweaks like a bit of plywood for support, you might be able to tape everything together and then just jack the hood back into place once the duct is secured. Sounds a bit tricky but totally doable!
That's an innovative idea! Lowering it down will give you some breathing room to work—just be careful with the balance!
Definitely give it a try. Just be mindful of the weight distribution while you’re lowering the hood—it can be a bit tricky!
I agree! That sounds like the right move. Just make sure the duct faces the right direction to connect properly. And yes, flaring the end should help fit it better over the port.