Dual duct system

[Anonymous]

Hi,

I would like to reproduce (family) a dual-duct system which the fan is inside a room used as plenum. (See attached drawing). The airflow of each cold zones should be added to find the total flow of the fan. What would be the ideal parameters for the creation of this family? Thank you.

Luc

[asommer]

If the "Room" is a big plenum, you will not be able to get the flow values to the fan.  you need duct connecting all of this.

[Anonymous]

Hi,

Yes. The room is a big plenum.

However, I wondered, to avoid errors, if I could create two families, one hot side fan  and another cold side fan. What do you think of that?

Regards,

[asommer]

That might make it easier to work the flows out, but I think you would still have to duct it up.  What this really looks like is a Rooftop unit with vestibules on it.  It just seems odd to place a fan in the middle of the room and not duct it up, just pressurizing the room...

I think you might get tripped up not ducting it up solid.  You would have to use values from the Space, in which you would have to place diffusers to give the space an "Actual Supply CFM" value.  I don't know how to do this where the space is in the middle of the system and not on the end...

Sorry i can't help you here, but please post if you find a solution.

[Anonymous]

Hello,

I created two families (fan system), one for the cold deck section and the other for the hot deck section. For now, this approach meets my needs and it works well. All dual duct terminal units are placed but not connected. Therefore, no flow calculation can be done for now. I'll come back later with more comments.

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