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Community and Q&A

Positioning an HVAC Supply Line

PLIERS | Posted in General Questions on

Hi hope all is well, and as always thanks for all the advice. Right now I have a supply line, (forced air, gas furnace) that is open in ceiling of basement. It does not have a register box, it is just hanging there open. I’m wondering if I should just add a register box in the ceiling and call it a day or if I need to bring it down and shoot it out of a wall. Im assuming heat rises so in winter I would want it more towards the floor? Not sure if it matters, it will also take several turns to get it into position for a wall placement. Is there a set guideline for ducts, like it is supposed to be positioned xyz from the floor?

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  1. Expert Member
    BILL WICHERS | | #1

    You're sure this is a supply and not a return? I've seen open duct returns in basements before. I would absolutely put a register on any open duct, and a damper too. If you have an open duct, it will be the path of least resistance and will tend to hog airflow from the rest of the registers. You'll never get good balance with a system like that.


  2. Jon_R | | #2

    Important wrt duct/airflow balance are two issues:

    a) are all rooms comfortable?
    b) are rooms being excessively pressurized or depressurized?

  3. PLIERS | | #3

    The second floor has been always difficult. The attic is the second floor there is no space above the roof is separated by joists and that's about it. It's also has minimial insulation. In winter the second floor gets hotter than the first and in summer the second floor takes more to cool down. During summer I close all the vents manually on first floor to a small opening and open the vents upstairs fully vice versa in winter. With fans and controlling vents I can get closer to comfortable on most days. The hottest sunny days gets more difficult. Sounds like I should put a register in ceiling with damper for this basement wether it is supply or return and then figure it out from there. Insulating the basement as I plan to do should help out the overall system.

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