Error when using LocalEnvironment objects with airflow network - why?

asked 2019-11-21 09:05:25 -0600

Agnese's avatar

updated 2020-01-07 17:15:44 -0600

Hello, I am trying to use the LocalEnvironment objects (both the SurfaceProperty:SurroundingSurfaces and the ZoneProperty:LocalEnvironment) to change the outdoor boundary conditions (air temperature, wind speed and surrounding surface temperature) of specific thermal zones of a naturally ventilated building modelled with the Airflownetwork.

I've used EnergyPlus example idf files for reference. However, after adding the LocalEnvironment objects, I have this kind of sever error with the Airflow-network: The entered number of external nodes is 22. The entered number of external surfaces is 18 This happens even though I don't add any node to the airflow-network.

Anyone has a possible explanation or happen to have the same problem?

Thank you!

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I haven't personally used those, but if you upload your IDF it'll help.

Jason DeGraw's avatar Jason DeGraw  ( 2019-11-23 11:12:22 -0600 )edit

Hi Jason, this is the first time I ask a question in UnmetHours and I cannot find where to upload the idf file? The format is not allow as attachment to the message. Sorry for the silly question!

Agnese's avatar Agnese  ( 2019-11-26 04:53:28 -0600 )edit

Since IDFs can sometimes be large, it is probably best to consider sharing the file with a link (using Dropbox, for example) rather than directly uploading it. For a direct upload, I think I recall people changing the IDF extension to TXT (since the IDF file is just a text file), but that may not work if the file is too big.

Jason DeGraw's avatar Jason DeGraw  ( 2019-11-27 06:59:00 -0600 )edit

Many thanks, Jason.

Here are the IDF files:

In the file “Cadiz-LocalNode” I have added a SurfaceProperty:LocalEnvironment object and an OutdoorAir:Node (Local_15) to set the hourly windspeed for an external surface (surface 145). In the file “Cadiz_SurroundingSurfaces” I’ve added a SurfaceProperty:LocalEnvironment and a SurfaceProperty:SurroundingSurfaces object for the external surface 145. In both cases, I get the same severe error “GetAirflowNetworkInput: Errors found getting inputs” which terminates the simulation

Agnese's avatar Agnese  ( 2019-11-29 04:50:04 -0600 )edit