Ask Experts Questions for FREE Help !
    logan176's Avatar
    logan176 Posts: 341, Reputation: 6
    Full Member

    Jan 14, 2018, 08:34 PM
    Is it possible to conceal this duct within the basement ceiling?
    When I had a new furnace installed 10 years ago, I needed to install return vents into the upstairs bedrooms of my Cape Cod style home. The HVAC company ran a single 12" round duct from the main trunk across the basement ceiling, up through a bedroom closet, and up to the second floor. From there, the one 12" duct branches off into two bedrooms.

    I'm trying to figure out if there is any way to conceal the basement duct into the ceiling without throwing off the flow of air from the upstairs bedrooms.

    The best option I've been given so far would be to pan off the joist bay to get the most volume of airflow as possible. If my math is correct, a sealed and covered joist bay still would be less than the volume of air in a 12" round duct. However, I don't think I'm getting full flow out of the current set up because the portion of 12" flex that goes from the rigid duct to the main trunk was compressed into the bay to squeeze above the main support beam to the house.

    If I was to pan off the bay, I can't figure out how to connect that space cleanly to the 12" flex that's already there or to the return main.

    Attached Images
    ma0641's Avatar
    ma0641 Posts: 15,681, Reputation: 1012
    Uber Member

    Jan 14, 2018, 09:03 PM
    12" duct has 113 sq. in. Your joist spacing X joist depth=? Pretty common to use dead joist space as a return but you could use as a supply. Put the duct into the vertical space, use orange fire block foam to close off the side holes(should have been done anyway). Fashion a plate from flashing to cover the chase but not the duct. Use flashing across the duct dead space, UL approved metal tape to seal the flashing and then duct mastic.
    logan176's Avatar
    logan176 Posts: 341, Reputation: 6
    Full Member

    Jan 14, 2018, 09:40 PM
    The bay dimensions are 14x7.25, so that gives me 101 square inches. If I understand what youíre saying, it sounds like you are explaining how to attach the vertical duct into the bay I want to close off. I know how to make that connection. Iím not sure how to connect the bay I want to cover to the main return trunk that would be to the left in the third picture above. Right now, there is flex duct, but I can see how I would connect the bay I want to seal off.

    The other horizontal return runs between the joists in the ceiling were panned off like you describe. But I canít see how they connect to the main trunk. Would I have to drop the return trunk to make that connection?

Not your question? Ask your question View similar questions


Question Tools Search this Question
Search this Question:

Advanced Search

Add your answer here.

Check out some similar questions!

Can I replace 12x8 cold air return duct with 12 inch flex duct in my basement? [ 2 Answers ]

I need head room in my basement and want to take down the old cold air return metal duct work 12x 8 and re-route to the plenum with 12"flex duct. Will this be a problem with the furnace working properly? Please advise

Cold air duct in the basement ceiling [ 0 Answers ]

The basement is concrete. It appears we will have to go to the other side of the concret wall and run duct work from the furnace down the wall which means removing a cement block for a cold air return. I think it makes more sense to leave the cold air duct in the ceiling... Dry wall around it and...

How to conceal electric wiring to dining fixture on concrete ceiling [ 6 Answers ]

Would like direction on covering up the feeder wire to long cord plug in pendant dining room fixture - concrete ceiling. We can bore a lge hole at one end of wall (plaster) into adjacent closet for outlet and even control juice at outlet with wall switch....but what to do about cord from center of...

6' duct for basement [ 2 Answers ]

Can I use 6" duct for venting out a basement? I will have four runs coming off the main duct, two in the 12 x 22 bedroom, two for the pool table open area - roughly 20 x 40 - with two vents per duct run, and then one more for the work out room 16 x 20. Thanks

Basement ceiling exposed duct, pipes and wires [ 1 Answers ]

My basement ceiling to floor measue 72" from floor to drywalled ceiling. My problem the prior owners attached ductwork and wires over the drywall. A suspended ceiling will not work takes up too much height. Walls and floor concrete. Any suggestions would be helpful. If I could see some...

View more questions Search