Importing back custom HVAC systems from an OSM file

@mostapha thanks!

Curious if you had any workflow recommendations for using OpenStudio’s graphical interface to customize the HVAC systems.

My thought is to assign a HVAC system in Rhino then save the model as a .osm file to customize them more with the graphical interface. What’s the easiest way to get the changes back into a HBJSON format from OpenStudio?

Hi @marentette ,

This is one that @mingbo should weigh in on as the author of the detailed HVAC workflows with the Pollination Rhino plugin and Ironbug. But I know that both Mingbo and I agree that the OpenStudio Application is a great way to learn about HVAC systems. Its interface for displaying the loops and zone equipment has a nice balance of detail and abstraction that makes it possible to understand how the controls and setpoint managers of the HVAC operate, which is often the hard part of understanding a particular HVAC architecture.

However, once you have an understanding of a particular HVAC architecture, I really wouldn’t recommend the OpenStudio Application as a way to edit HVAC systems for at least a couple of reasons:

  1. It has no “Undo” button. There have been many situations where I have accidentally broken something in an OpenStudio HVAC and I just want to go back but cannot since the OpenStudio App was designed in a way that “Undo” is un-support-able. In this situation, I usually end up trashing my current model and starting back from an older version that I saved. Granted, if I only need to perform a couple of tweaks to the HVAC, this type of workflow is often fine. But, this is usually going to happen several times for a case of serious HVAC editing and you can imagine how annoying this gets after it happens more than once.

  2. There isn’t a great way to encode repeatable logic about the HVAC system in the OpenStuido App so that I can reuse it as the project design changes or to apply it across several different projects. Granted, this criticism is something that applies to almost all BEM platforms and I really shouldn’t fault OpenStudio too much for this because they actually do support a way of encoding reusable HVAC logic by writing your own measures. But my experience has been that the vast majority of people are not going to learn Ruby, OpenStudio SDK, and Measure conventions in order to be able to encode reusable HVAC logic. I know a few people who have managed to become a Ruby/OpenStudio SDK experts but they are often working in teams where everyone else doesn’t know Ruby and so the whole endeavor doesn’t go very far given that there’s only one person on the team who can edit the HVAC through the measure.

On the other hand, through Ladybug Tools, we’ve managed to engage a community of over 200,000 people in the combined skillset of visual scripting with Grasshopper and energy modeling with OpenStudio. And, as a scripting interface, Grasshopper can be used to specify reusable HVAC logic. Add to that the fact that Grasshopper has the vitally important functionality of “Undo” and you can begin to see why we recommend Ironbug/Grasshopper as the best way to edit detailed HVAC with Pollination. @mingbo has been working on a set of commands in Pollination Rhino that better integrate these capabilities with the Pollination plugin and we’ll hopefully have some good documentation soon on the full workflow that we recommend here. But, if you want to get started by familiarizing yourself with Ironbug, you’ll be able to more readily make use of the workflows as we roll them out. You can see there’s a whole category devoted to Ironbug on the LBT forum, which can help get you started.

Lastly, to answer this:

There’s currently no way to bring an HVAC system from OpenStudio to HBJSON. We can bring the geometry and most of the other properties but trying to import all of the possible detailed HVAC components from an OSM file is a monumental task. You can already see that Ironbug has over 150 different components and these don’t even cover every HVAC component that can be specified in OpenStudio. So we don’t have plans to support this anytime soon.

In any event, if you start learning Ironbug, we promise that we’ll make it worth your time with what we have coming down the development pipeline.