I have a model with a solid oxide fuel cell CHP included. The example file MicroCogeneration.idf I have adapted it from has a PTAC but my modelled building does not so I've removed it. I think the issue that EnergyPlus is flagging up in the .err file is that there are dangling connections where the PTAC was previously.

Have I understood this correctly? Do these errors matter? And if they do, how do I prevent them? The model runs anyway so it seems like this may not be an issue but I'd like to confirm one way or the other.

Extract from the .err file:

************* Testing Individual Branch Integrity
************* All Branches passed integrity testing
************* Testing Individual Supply Air Path Integrity
************* All Supply Air Paths passed integrity testing
************* Testing Individual Return Air Path Integrity
************* All Return Air Paths passed integrity testing
** Severe  ** Node Connection Error, Node="BUILDING:SAPZONE2 INLET NODE", ZoneInlet node did not find an outlet node.
**   ~~~   ** Reference Object=ZONEHVAC:EQUIPMENTCONNECTIONS, Name=BUILDING:SAPZONE2
** Severe  ** Node Connection Error, Node="BUILDING:SAPZONE2 EXHAUST NODE", ZoneExhaust node did not find a matching inlet node.
**   ~~~   ** Reference Object=ZONEHVAC:EQUIPMENTCONNECTIONS, Name=BUILDING:SAPZONE2
************* There were 2 node connection errors noted.
************* Beginning Simulation