Mapping HVAC / Airflow in Indoor Cultivation Cleanrooms

I am a long time SketchUp user and have spent the last few years founding and designing our proof-of-concept indoor cultivation facility, reliant on others for advice on HVAC thermodynamics / airflows. I’d like to be able to cross-check designs myself and have created a test room here for this purpose.

I have rebuilt and cleaned up an STL import of my model. Looking for some assistance configuring for simulations.

A little more detail; I need to configure 1no. standalone HVAC unit and 4no. of re-circulating ingress/extract paired grilles.

Hello GoodwoodRS4!

First off, welcome to the SimScale platform and our Forum!

The indoor HVAC problem you’re describing sounds like what many of our users have successfully simulated with the platform. I want to provide a link to the Office Room HVAC tutorial as it serves as a great starting point to understanding the simulation workflow from start to finish using the Convective Heat Transfer Analysis Type. Here’s the link: Thermal Comfort In a Meeting Room | Tutorial | SimScale

After looking at the project you’ve created, let me leave you with some notes to help you get started:

  1. It’s best to work with the CAD formats that are supported for all the analysis types; check out the list here: CAD Preparation & Upload | Simulation Setup | SimScale
    STEP files are a more ideal file type, since STL files are only guaranteed to be compatible with the Lattice-Boltzman solvers (Incompressible LBM & Pedestrian Wind Comfort) which are not the analysis types you’ll work with (again, the appropriate analysis type for your problem is Convective Heat Transfer).

  2. You need to create/extract the Internal Flow Volume of the room model in your project; the flow volume is the 3D body that models the negative space of the room where air is present. You’ll notice in the tutorial above that the simulation setup is done on this flow volume– this is the case with any CFD simulation as we are simulating the air in the flow region, not on the solid walls/bodies of the room. Here’s a great article that walks you through how to create/extract the Internal Flow Region: How to Create Flow Volume Extraction? | Knowledge Base | SimScale

  3. If you are interested in modeling any emissions/contamination or gases in the flow domain that passively flow with the air (e.g. CO2 gas), you can use the Passive Species modeling to embed them in your model, Another great tutorial to understand how to work with passive species is linked here:
    Car Park Contamination Simulation Tutorial | SimScale
    The tutorial above also uses the concept of Momentum Sources to model fans within the flow domain that don’t add new air from outside the room or push air out of the room (this is the way Boundary Conditions would behave). There are additional requirements in the geometry to set these up, so I would add them after you get your baseline case working without them.

Good luck in your first CFD simulation with SimScale! Feel free to provide updates here on the forum if there’s any success you’d like to share!


Hey Omar, thanks so much for reaching out so promptly. I was working through the creation of the Internal Flow Volume, which makes perfect sense, but keep running into issues with my STL model and faceted surfaces… As you expected.

Going to attempt re-creating the model in Fusion360.

I have recreated the model in Fusion360, seems to have worked much better. Going to try and follow one of the tutorials and see where I get to.