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Inlet Node Name is required but was blank

asked 2018-06-12 07:04:56 -0500

borui gravatar image

updated 2018-06-12 08:39:47 -0500

Dear all, I 've been trying a single zone for HVAC analysis for a while, simulation always ends badly. The most and big problem shows" field [ xxx Inlet/outlet Node Name] is required but was blank, and I check a lot of discussion in the forum which is similar to this one. But unfortunately, even I delete extra setting coils still can't fix it out.

Could someone please kindly help me on this issue? I'll be appreciated!

Attached file here.


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answered 2018-06-12 08:32:46 -0500

You have two problems: one is really easy to fix, the other is much more tricky (for new users at least).

Problem 1: trivial

** Severe  ** <root>[Coil:Heating:Water][Coil Heating Water 1] - Missing required property 'water_inlet_node_name'.
** Severe  ** <root>[Coil:Heating:Water][Coil Heating Water 1] - Missing required property 'water_outlet_node_name'.

The message should point you directly to the fix. If you look at your coil Heating water, it is placed only on your AirLoopHVAC, and it doesn't have a connection to a PlantLoop. I just connected it properly to the PlantLoop.

HW Coil Not connected

Problem 2: harder

You have one heating coil on your plantLoop, but this coil isn't on an AirLoopHVAC. Similarly, "CHW Clg Coil 2" and "Fan Constant Volume 4" are nowhere to be found... This is because you actually have an orphaned "AirLoopHVACUnitarySystem" in your model (orphaned=not placed on an AirLoopHVAC) and this unitary system contains the Fan, the heating coil, and the cooling coil. I removed it via the ruby bindings:

unitary = m.getAirLoopHVACUnitarySystems[0]

Now your model will run correctly. I have uploaded the fixed model here. Please note that it was upgraded to OpenStudio 2.5.1 (the version I have on my system), so you won't be able to load it in OpenStudio 2.4.0.

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Hi Julien, really thanks for your help. But I still have some more questions.

The orphaned issue might because I tried various HVAC system before and I wanna see what's the difference but it doesn't work, so after that, I delete them. I just assumed that it's clear but true is not... So, how to detect the invisible error in HVAC system? Measures?

And the other question is when pre-assigned in the Thermal zone equipment as a PTAC, but to the next page HVAC system doesn't show up any details, like hot water loop or the PTAC system itself, how to prevent that or make it right?

Really thanks!

borui gravatar imageborui ( 2018-06-14 23:12:35 -0500 )edit

I found your oprhaned object via the ruby bindings, but you could find it in a text editor, but removing it in a text editor wouldn't be safe: chances are you'll forget or mess up something in the process. On the thermal Zone tab, when you click on your PTAC you should see a link icon in the right panel, that's allow you to connect the hot water coil to a plant loop.

Julien Marrec gravatar imageJulien Marrec ( 2018-06-15 05:10:32 -0500 )edit

(FYI, I'm answering here because you're new, but 1. This is a new question that has nothing to do with this one, so it shouldn't be posted here, and 2. You could find the answer on this site by yourself, it's been covered more than once.)

Julien Marrec gravatar imageJulien Marrec ( 2018-06-15 05:10:48 -0500 )edit

Big thanks to Julien, I got it! Next time I'll be careful about that.

borui gravatar imageborui ( 2018-06-16 13:12:03 -0500 )edit

@borui, if the answer solved your problem, please remember to mark it as accepted by clicking the check mark to its left. It'll help us by flagging the thread as being resolved.

Julien Marrec gravatar imageJulien Marrec ( 2018-06-18 06:12:51 -0500 )edit

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Asked: 2018-06-12 07:04:56 -0500

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Last updated: Jun 12