Ironbug: How to model several airloops

Hi @MingboPeng,

We have a project where each zone has its own outdoor air system, but all zones are connected to the same VRF system.

I am getting a Failed to add all airloop demand components! error. I’m thinking it might be due to how I am trying to duplicate components. I have tried making the names of all the components explicit, but have noticed that the OASystem component does not have a params_ input so I can’t specify unique names for it:

The demand side looks fine to me but the two supply objects look identical.
Do you have any suggestions how to solve this? (542.9 KB)


Hi @MaxMarschall ,

VRF terminal has its own outdoor air setting at zone level, you will need to set them to 0 if you have a separate airloop with outdoor air system attached to zone.

In terms of why it failed to add rooms to airloop demand side is: you cannot add room directly to airloop, it needs an airloopBranches to add rooms at parallel branches.

Thanks @MingboPeng,

It works now, but I have noticed some very strange behavior:

The two definitions are identical (copy-pasted), except for the input into the ListLength component that is plugged into the Ironbug_Duplicate component for the OASystem:

In the top example, it is taken from the HBZones at the start of the definition; in the bottom example, it is taken from a later component. In both cases, the number outputted from the ListLength component is 2. If I enter “2” directly with a number slider, I also get the error message:

Is this a bug or have I made an error?
List (751.0 KB)

@MingboPeng I found the issue myself, which was that the Duplicate and FanConstant outputs ended up with different tree structures:

The solution was to simplify them: