Frequent lurker here coming out of the closet…

We are doing a gut reno of our brick/frame house, doing the work ourselves. We’re currently working on the ground floor (interior) bathroom. We got a Panasonic whisper fan, choosing a pretty powerful one not for the size of the bathroom, but because there’s a pretty long run to the outside (25 feet). We get to install the duct ourselves, and decided to go with flexible aluminum ducting, but we’re having a hard time installing the actual duct to the fan. It’s driving me (and really, my dear husband) nuts. The duct just seems to big to clamp on to the duct outlet on the fan.

Is there a secret that’s not in the manual that anyone can help out with?


Comments

  1. There is a crimping tool that puts ripples into the now smaller fitting, allowing (2) 6″ fittings to join. Work around the circumference carefully. They do have it at Home Depot if you know what to ask for.

  2. Place the screws towards the top of the vent or sides. Just insurance since tape will eventually weaken. Alum. foil tape is like more expensive duct tape.

    You might be able to crimp the larger duct since it’s flexible stuff. If done carefully and taped, there will be no leaks.

  3. Place the screws towards the top of the vent or sides. Just insurance since tape will eventually weaken. Alum. foil tape is like more expensive duct tape.

  4. We have 6 inch duct and the fan duct diameter is also 6 inches, so it’s not a question of mismatched sizes. The flexible aluminum duct measures a bit bigger (6 1/4, actually, although it was sold as and is labelled 6 inch duct. We got it from Grainger.

    CMU: the screws are to hold it in place? Puncturing it won’t cause, I don’t know, condensation to drip?

    And this aluminum foil tape stuff, does it have an adhesive?

    Thanks all!

  5. Considering that the ducts will be completely concealed, use at least a couple of sheet metal screws for mechanical fastening, then the alum. tape.

  6. It may be that your duct size is 4″ diameter and the diameter on your bath fan is 3″. A 4″ to 3″ reducer should do the trick like quest said. Use a lot of aluminum foil tape on all the joints to prevent leakage. It grabs much better than duct tape.