Snapshot Manager: Missing IDF version declaration

I ran into an issue, while I tried to import the IDF from the Snapshot Manager to Designbuilder. (Pollination: v2.187.6)

Designbuilder gives an instant error if there is no IDF version description/declaration at beginning of the file.
Is it possible to add this simple info to the IDF file?

I’ve tried to bypass this by guessing the IDF version. It made possible to open the IDF file in Designbuilder, but the model became a complete mess :slight_smile:

Designbuilder converts IDF to gbXML during the import process, so it would be nice if Snapshot Manager would be able to export gbXML directly. (I know it’s a planned feature, but I would like to put emphasis on this)

By the way I’m really impressed by the Snapshot Manager’s feature, looks really promising!

My Dummy:

Hi @drumman,

I know that DesignBuilder uses an older version of EnergyPlus. It is unlikely that the IDF generated from the latest version of the model editor work with DesignBuilder. @chriswmackey should be able to tell about the correct version of the IDF file that is currently generated by the model editor.

And yes, we will add the functionality to directly export to gbXML.

Thank you! We are just getting started with it. Stay tuned for the upcoming release that should fix this issue.

OMG! The IDF version incompatibility is doing some magic there. Can you try to export to gbXML directly from Step 9 of the Export Model workflow instead, and see if that solves the problem? It has been a while since I have seen an exploded model like that. :expressionless:

Just so you know, and this will be the long-term solution, we are working closely with the DesignBuilder team to support their internal XML format so we can bypass the challenges of using gbXML and IDF for interoperability.

1 Like

Hi @drumman ,

Normally we pull the E+ version that we write into the IDF directly from the EnergyPlus installation. But we have not finished connecting the Model Editor to the local installation of OpenStudio/EnergyPlus (we should hopefully be there by the end of this week). Once we have that, you’ll be able to export gbXML, OSM and IDF (with the E+ version in it) from the Model Editor.

In the meantime, all of this gbXML, OSM and IDF exporting is currently available in Step 9 of the Export Model workflow as Mostapha said.

And to answer this question:

Pollination is currently using EnergyPlus 23.2 (from the end of last year). So that’s the version that you’ll see written into the IDF if you export from step 9. That is also the intended E+ version of the IDF that you’re currently exporting from the Model Editor.

DesignBuilder is currently using EnergyPlus 9.4 (from 4 years ago). Given how much the E+ dev team changes the IDF schema these days, the IDFs that you export from Polliantion are almost certainly going to be incompatible with an EnergyPlus version that old.

gbXML is the current recommended way of getting from Pollination over to DesignBuilder. The DesignBuilder team put together the most complete importer of gbXML that I have seen in any software to date and this should get all of the geometry to come over smoothly from Pollination to DesignBuilder.

That said, gbXML doesn’t have great support for all of the other features that we would like to get imported into DesignBuilder (eg. constructions, schedules, loads). So that’s why we are writing a translator from Pollination to the new DesignBuilder XML schema (dsbXML) that the DSB team just released. Hopefully, you should see that option available in the next couple of months.

1 Like

@mostapha @chriswmackey Thank you for the quick and detailed response!

Step 9 Export Model works perfectly, I’ve tried before - forgot to mention.

I’m a bit suprised that gbXML is not “enough” for the detailed data transfer with schedules, HVAC etc, but it’s good that Designbuilder team has resolved this bottleneck!

Out of curiosity I’ve checked what EnergyPlus version is Insight using: v8.5

to deviate the topic:
My actual small test case is more complicated building, with coulmns, multiple walls combined etc…
I would like to try an extreme scenario when “I’m not allowed” or “It’s not possible” edit the Architectural model (switching off the room boundary parameters for the releavant instances) and all of these issues need to be resolved in the Snapshot Manager to export the model to Designbuilder. It seems doable.

DB result without any changes made to the archicetrual model, using the Exporter only:

I will look for the update and make a clear model out of this mess with the Snaphot Manager! :slight_smile:

1 Like

Hi @drumman,

Excellent! That makes me feel better.

To be honest, I haven’t tried this functionality with DesignBuilder myself. You should give it a try and see if it works. The constructions and schedules are the easier ones. I will be surprised if the HVAC translation works.

It is very doable! I would be more than happy to record a video to show how to clean up this model in the model editor. It should not take more than 5-10 minutes to get it all fixed.

All great things to hear, @drumman.

Just to give a little more info about this:

I should clarify that gbXML has schemas for objects like constructions and schedules but they made some decisions about them over a decade ago that seem like they were more geared towards DOE-2 support instead of E+ support. For example, there is no support in gbXML for multi-layered window constructions or frame objects. The only option gbXML supports is defining window constructions with a U-Value and SHGC. With the DesignBuilder XML schema, we should be able to bring over lots of detailed information like this.

I also want to set expectations that HVAC is a very complex thing to translate between any platform. It’s definitely not feasible for us to make a map between Pollination and DesignBuilder HVAC using gbXML’s schemas. Even with the new DesignBuilder XML format, we may not be able to bring over any more of the HVAC system beyond thermostat setpoints, outdoor air requirements, and a general flag for whether a given room is supposed to be conditioned or not. But we will see. Both DesignBuilder and Pollination have this somewhat abstracted way of defining HVAC template systems and I would love to make a translation pathway between these two if we find that it’s possible.

I’ll try to remember to post back here once we have a dsbXML export pathway ready to test.

1 Like