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fttang's avatar
fttang
Explorer
Mar 02, 2014

using ducted roof ac as non-ducted?

i have a 2004 ford e350 that has factory rear ac with duct and vents built into the headliner, which leaves no space on the roof for interior air box of roof ac units.

after some research, i came up with an idea to use a ducted roof unit with separate thermostat, and connect the factory duct to the ac unit.
it wouldn't be a real ducted application because the factory ducts are really small and short, so it's more like a non-ducted application without using factory air box.

any ideas?

ok more explaining:

this is a typical roof unit, blue is the opening required on roof, red is the cold air coming out


this is my headliner(interior ceiling), as you can see blue area(required for air box) is too large and will block factory rear AC duct.


so i was thinking if i can connect the red part on the roof unit to a red opening shown here, and utilize the factory duct, with a separate thermostat that ducted units would have.

the unit would still work as a non-ducted as the factory ducts are really short, so the air would be coming out pretty much directly(as if coming out of air box).
Class B

11 Replies

  • stan909's avatar
    stan909
    Explorer
    Mar 05, 2014
    If pushed for an answer my answer is no.roof top airs have the return and controls that will hang down inside the van ceiling. You could possibly use a Koolkat type air which looks like a window air back by the vans rear air. Tie into the ducting there but you would lose space inside your van. You could also forget about trying to use the ducting altogether and locate your roof air toward the front of the van but that could result in some head bumping.
  • fttang's avatar
    fttang
    Explorer
    Mar 05, 2014
    Bumpyroad wrote:
    stan909 wrote:
    You may have to choose one or the other. If understand you correctly , you wish to ad a rooftop AC and run it through your existing duct work while still being able to use the automotive air. This will be the first time I've seen anyone do this. I think you're on your own but I would like to see how it works out. Good luck.


    by automotive air I assume you mean dash air? don't see where that enters into the discussion.
    bumpy


    stan909 is pretty much right, although i am not trying to use them at the same time(i will only run one of them at a time), just don't want destroy the existing duct work.

    can anyone answer my question of using a ducted AC unit as non-ducted? if the answer is yes then what i need to do is pretty much connecting the AC to the factory ducts.

    bumpy, my van has a separate evaporator mounted in the rear, which has ducts into the roof, the evaporator is connected to the "dash air"(engine mounted compressor and coolant).
    they don't have much to do with what i am trying to do, it is the ducts that matters.
  • Bumpyroad's avatar
    Bumpyroad
    Explorer
    Mar 04, 2014
    stan909 wrote:
    You may have to choose one or the other. If understand you correctly , you wish to ad a rooftop AC and run it through your existing duct work while still being able to use the automotive air. This will be the first time I've seen anyone do this. I think you're on your own but I would like to see how it works out. Good luck.


    by automotive air I assume you mean dash air? don't see where that enters into the discussion.
    bumpy
  • stan909's avatar
    stan909
    Explorer
    Mar 04, 2014
    You may have to choose one or the other. If understand you correctly , you wish to ad a rooftop AC and run it through your existing duct work while still being able to use the automotive air. This will be the first time I've seen anyone do this. I think you're on your own but I would like to see how it works out. Good luck.
  • fttang's avatar
    fttang
    Explorer
    Mar 02, 2014
    georgelesley wrote:
    My only concern would be if the opening is large enough for the proper amount of airflow without obstruction if I understand what you are trying to do.


    i intend to open a hole in the headliner duct(red circle) that's the same size to the AC unit,

    the blue area as for as i understand does not have anything to do with airflow, and i will open that in the metal roof, just don't have the space on the headliner.

    so in theory would this work?
  • fttang's avatar
    fttang
    Explorer
    Mar 02, 2014
    Cuffs054 wrote:
    Fttang, where would the unit get it's return air?


    if that's the black square hole shown in the back of AC unit, i can open a hole in the headliner and use plastic tube to duct it.
  • georgelesley's avatar
    georgelesley
    Explorer
    Mar 02, 2014
    My only concern would be if the opening is large enough for the proper amount of airflow without obstruction if I understand what you are trying to do.
  • Bumpyroad's avatar
    Bumpyroad
    Explorer
    Mar 02, 2014
    I have seen RVs with ducted air that had a "fast cool" function or somesuch where you could open the slats and have it in a direct downflow condition.
    bumpy
  • fttang's avatar
    fttang
    Explorer
    Mar 02, 2014
    camper19709 wrote:
    ???????
    Have no idea what you have or what your trying to do.
    More info needed.


    basically i have no space inside the van for non-ducted ac's air box,
    and trying to install one with separate thermostat instead of ceiling air box, and route the cold air into the factory ducts.

    or think it the simple way, can i install a ducted AC, with a thermostat, with no duct but just a hole(for cold air) in the roof?

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