Click here to Find a Contractor in your area.
Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit

Air condition from basement upward?

Can I get effective high velocity /small duct air conditioning in a two story  home

with the air handler suspended from the basement ceiling ,

with a plenum  along that ceiling, and duct work up into the walls of the first floor , and into  floor outlets in the second floor?

With added outlets for friction losses, could I even go to high on the wall of the second floor for outlets using closet routes.?

 We have 8 feet ceilings and  2 X10 joist cavities.

In Minnesota I do not want to create holes in my attic floor downward into the house.


  • Techman
    Techman Member Posts: 2,144
    Hi Velocity

    If memory serves me right all of the takeoffs are supposed to be pretty much the same length so 1st floor/2nd floor is not equal .
  • joe_94
    joe_94 Member Posts: 39
    well, sort of

    Yeah, I have seen something like that, but also that though  long runs may provide less cold air,  adding another can make up for it.

    My basic question is less intelligent:  Can the system boost the air upward adequately?

    It does this in conventional  furnace- based systems.

    I had thought  maybe I could  add  a vertical element in the plenum, to get mainstream air higher before breaking off into  feeder lines. Perhaps the plenum could be like an "H" laid on its side.

    Help, anyone?
  • Techman
    Techman Member Posts: 2,144

    IF you looped up the extra length for the 1st fl  branch ducts,then the air on the 2nd fl branches would be even w/the 1st fl.But, if you dont loop up the 1st fl supplies AND YOU know how to properly add an extra supply or two for the 2nd fl to offset the supply imbalance on the 2nd fl ,please let us know. If you put this system in on your own and it does work properly PLEASE keep us advised . I am always willing to learn new ways.And Hi-V main supply trunk layout is not the same as conventional ducting.
This discussion has been closed.