# CFD of oper terrace area (Arch and hvac )

**URL:** <https://www.simscale.com/forum/t/cfd-of-oper-terrace-area-arch-and-hvac/101015>\
**Category:** Project Support\
**Created:** [May 2, 2026, 11:04pm UTC](https://www.simscale.com/forum/t/cfd-of-oper-terrace-area-arch-and-hvac/101015 "2026-05-02T23:04:44Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![mdrnazish](https://www.simscale.com/forum/letter_avatar/mdrnazish/32/5_5575768a8748004e209b776fc1b2916d.png) [@mdrnazish](https://www.simscale.com/forum/u/mdrnazish)\
**Post date:** [May 2, 2026, 11:04pm UTC](https://www.simscale.com/forum/t/cfd-of-oper-terrace-area-arch-and-hvac/101015/1 "2026-05-02T23:04:44Z")

</div>

I am working on a CFD simulation using a Revit (STEP) file. The model includes both architecture and HVAC components in a single file. My objective is to analyze airflow and temperature on an open terrace where HVAC units are placed.

For this purpose, I selected a **Conjugate Heat Transfer (CHT)** analysis. I assigned:

- **Air** as the fluid region

- **Steel and concrete** as solid materials

After setting up the model, I applied boundary conditions such as **velocity inlets** and **pressure outlets**.

However, when I try to run the simulation, I encounter multiple errors related to boundary conditions and region assignments. It seems that some boundary conditions are incorrectly applied to solid regions instead of fluid regions.

Additionally, every time I upload a new STEP file or refresh the page, I repeatedly receive the same warnings for all simulations, and I have to manually review them each time. This is making the setup process very time-consuming.

I suspect there may be an issue with how the geometry (fluid vs. solid regions) is defined or extracted.

Could you please guide me on:

- Correctly defining fluid and solid regions for a CHT simulation

- Properly assigning boundary conditions only to fluid domains

- Avoiding repeated warnings after re-uploading or refreshing

- Whether I need to re-create or extract the flow volume separately

I can share the project link if needed.

---

<div class="post-metadata">

**Author:** ![BryanArsenio](https://www.simscale.com/forum/user_avatar/www.simscale.com/bryanarsenio/32/71634_2.png) [@BryanArsenio](https://www.simscale.com/forum/u/BryanArsenio)\
**Post date:** [May 5, 2026, 11:18am UTC](https://www.simscale.com/forum/t/cfd-of-oper-terrace-area-arch-and-hvac/101015/3 "2026-05-05T11:18:56Z")

</div>

Hi @mdrnazish

Would it be possible for you to let me know the project title and share the project with support if it is private? That way I can take a look and analyze the problem deeper.

Thanks!  
Bryan