Confusting ApacheHVAC 'Invalid configuration' error

[clorenz531]

I'm currently modeling a building which has two air handlers. I pulled in prototype system 05a, copied it, assigned the appropriate rooms to the multiplex and that's it.

The room loads run fine, but when I try to do system sizing runs (or do a network check), I get the following error:

Network is not valid. Reason:
Invalid configuration: Selected multiplex[ID: MU000101] contains a duct-only section, re-route this to be outside the multiplex. resizing the multiplex may help.

What does that mean? The multiplex it refers to literally has the exact same layout as my other system, but that one works fine. What could be causing this error?

[PCully]

Hi,

See Section 8.1.1 of the ApacheHVAC user guide for description of the Multiplex rules. It sounds like you have a run of duct/connectors with no components within the Multiplex (i.e. between where the section enters and exits the multiplex boundary there are no components defined). These need to be outside the Multiplex or it will fail.

Check the rules and then have a look at your network to try spot the source of the problem.

If it doesn't look like you have broken any of these rules then you might have some sort of corruption in that Multiplex, check that components are on all layers of the Multiplex and that kind of thing and usually you could resolve by redoing the multiplex or delete and redraw any problematic components.

Phil