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# node connection error [closed]

I get this following errors after putting a four pipe fan coil into my air loop in my energyplus

Severe * Same component name and type has differing Node Names. * ~~~ * Component: COIL:COOLING:WATER, name=FCU-LC-09 * ~~~ * Nodes, inlet: NODE 10, outlet: NODE 12 * ~~~ * & Nodes, inlet: UNDEFINED, outlet: UNDEFINED * ~~~ * Node Types: Air Nodes & UNDEFINED * Severe * Same component name and type has differing Node Names. * ~~~ * Component: COIL:HEATING:WATER, name=HW HTG COIL * ~~~ * Nodes, inlet: NODE 12, outlet: NODE 57 * ~~~ * & Nodes, inlet: UNDEFINED, outlet: NODE 7 * ~~~ ** Node Types: Air Nodes & UNDEFINED

May I know how to resolve them?

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### Closed for the following reason the question is answered, right answer was accepted by davis close date 2020-10-10 00:02:00.793533

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You need to check node names (did you have a sketch of you system with node name? It could be useful): NODE 12 is FCU-LC-09 Coil:Cooling:Water outlet node as well as HW HTG COIL Coil:Heating:Water inlet node name, that obviously cannot be (it has no reason).

Moreover you have as "UNDEFINED" 2 nodes on CHW Coil (maybe air node?) and 1 node on HW Coil.

You have to set properly insert these objects on both Air loop(s) and CHW/HW loops

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May I know why the outlet node of the cooling coil cannot be the inlet node of my heating coil? because I put them one after the other actually

My second question is what does undefined node means and where do I check them? This is because I actually set everything in openstudio first before exporting it to idf so the node should be properly assigned as well.

P.S one thing to note is that I set my Four pipe fan coil in energyplus instead of openstudio

https://drive.google.com/file/d/1sRzv... - this is my idf file

( 2020-10-04 11:33:47 -0500 )edit

I got a bit confused, I let myself be fooled by the error reported, thet let me think about a fan coil unit inserted in an air loop. Indeed this is looking at your file, BUT ZoneHVAC:FourPipeFanCoil is a zone HAVC component that cannot be put in an air loop as you did. Please look at I/O Ref for this obj to properly insert this object in your file.

( 2020-10-05 07:24:06 -0500 )edit

(cont) About your first point i thought the CW then HW connection was at water loop level (the only loops actually the component can have), and therefore without any sense

( 2020-10-05 07:26:00 -0500 )edit

Thank you for your advice. I have refer to the document and hook up the FourPipeFan coil as instructed.

However, I am experiencing this new error:

* Severe * An outlet node in AirLoopHVAC="AIR LOOP HVAC 1" is not connected to any zone * ~~~ * Could not match ZoneEquipGroup Inlet Node="NODE 5" to any Supply Air Path or controlled zone * Fatal * Preceding errors cause termination

May I know if you know this error?

Attached is my idf file: https://drive.google.com/file/d/1_Oxq...

( 2020-10-06 09:39:31 -0500 )edit

I've started with :

AirLoopHVAC:SupplyPath node 4 --> node 5 (Air Loop HVAC 1 Demand Inlet Nodes) add in NodeList for Learning Workshop Node 7 (to cover ADU) in addition to Node 4 (covering FCU) and put in the Zone Air Inlet Node or Node List Name (in ZoneHVAC:EquipmentConnections) the previous Zone List with node 7 added ....

But any time Severe Errors occurs. You have to deeply review all nodes/branches !!! For example Node 4 (and related obj: HW Htg Coil) apperas both on fan-couil unit (FCU) and in Air Loop HVAC 1 Main Branch !! My suggestion , as I stated in the first comment,

( 2020-10-07 05:33:36 -0500 )edit