I have a space in finish basement where I have to supply heat from ceiling. But in ceiling, in some places, main supply trunk is not reachable or some occupied by other vent for upstairs. Now I am ending up with reuse the existing branch of 7" flexible duct, which goes up stairs currently. I think I just have add a tee and then attach boot. I know cons of splitting the supply.

I need to know what register vent boot, do I have to use which is compatible with duct tee or How do i achieve this ?

The joists in ceiling running 16 inch center and 2 in. x 10 in. in size. The floor space in basement is 180 sqft

Any help will be highly appreciated.

  • Clear, focused, well lit pictures of the areas in question, along with dimensions (have someone hold a tape measure up in the pic on a key dimension, others can be estimated from there) will help immeasurably!
    – FreeMan
    Apr 27, 2021 at 12:06

1 Answer 1


Splitting that 7" flex duct to two ducts will yield very little heat to either room. I would find another "tap-in" spot off the main trunk to get heat for the basement. Can you add a supply register to the bottom of the supply trunk.

A picture or two would help us understand what you want to accomplish, what problems you are encountering, and what options we see that would resolve this problem.

  • I like the idea of adding supply register to the bottom of the main trunk. but it close to return. I'll post a picture soon. thanks
    – PowerTech
    Apr 27, 2021 at 22:06

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.