Focus

The focus of this stage in your integrated design project is to explore how you can best implement the strategies that you identified for achieving your project goals as you design the features of your building’s HVAC system.  For this check-in you’ll add these features to your building model:

• HVAC Analysis Features
• Spaces
• HVAC Zones
• HVAC System Elements
• Air-Based System Components
• Ducts
• Air Terminals
• Ducts
• Zone Controllers
• Air Handlers
• Fluid-Based System Components
• Piping
• Radiators

Recommended Approach

At this point in our design process, we’ll continue adding the details to flesh out our initial building design ideas -- for this check-in, focusing on your overall heating, ventilating, and cooling strategy and the HVAC system elements that will illustrate your proposed systems.

How Detailed Should This Version of Model Be?

Our goal in modeling the HVAC system is to understand the impacts of your design decisions and find ways to improve your design -- NOT to create a perfect Revit model.

At this stage, you’ll want your mechanical model to accurately reflect the locations of the major elements and essential components of your HVAC strategy. But to keep this assignment from becoming overwhelming, you should:

• Keep your system modeling very high level.
• Get the main components in your HVAC strategy modeled to illustrate how they’ll work together with the other building systems...
• Learn to let go of the small details when you’re in this design exploration phase.  The details will get resolved later in the process.

It’s very easy to get lost in all the detail of modeling the HVAC system components -- for example, getting all the ducts to connect properly can be very tricky, especially if they get very large when you resize them to match the airflow required. So:

• DO NOT…  I repeat, DO NOT…  I repeat again, DO NOT agonize over the duct connections that just don’t want to connect as desired.  
• For the scope of this course and design project, you won’t be able to resolve all the HVAC details -- and that’s okay!  There will be lots of unknowns and issues for future resolution -- that’s typical, expected and okay!

What Size Should the HVAC System Elements Be?

Similar to our challenge when doing the structural design, the answer is -- we don’t know yet!

In practice, we can compute the overall and cooling loads for the overall building (or for each zone in the building) and use this information to pick appropriately-sized heating and cooling equipment.   But, selecting that equipment is beyond the scope of this course -- so, you can place some moderately-sized mechanical equipment as placeholders (to be sized by an HVAC engineer later).

Duct sizing is something that we can do now based on the supply air requirements that you’ve computed for each space.  As you get started modeling, place ducts using an approximate size -- say 12x12 or 12x16 -- as placeholders.  Then, you can use the Duct Sizing tool to compute the actual sizes based on the airflow demands of the terminal that you connect to each duct.

Does the HVAC System affect Other Systems?

The design of your envelope system, your structural system, and your HVAC system all have to work together:

• Your envelope system choices have a huge impact on the heating and cooling loads that your building will experience. So, careful envelope design can be used to greatly reduce the size of the components in your HVAC system.
• Your structural system choices have a big impact on the space available for placing ducts as part of your air-based HVAC systems. The layout and depth of the beams and beam systems often dictate the space and paths available for routing ductwork.

Progress Check-In / Documenting Your Design Journey

About Design Journal Entries

You’ll be sharing your ongoing design process and progress with others in our class community through a posting in an online Design Journal using Notion.

Feel free to use whatever format best captures the ideas that you want to share -- text, images, sketches, photos of hand sketches, intermediate models, results of analyses, and so on.

For this class, your design process is as important as the final result.

Post a Design Journal Entry

Create a new posting sharing your Design Journal entry on this linked Notion page:

Your Design Journal entries this week should highlight your design thinking and analysis results that influenced your decisions about:

• your overall HVAC system strategy
• your heating strategy and how you implemented it in your design
• your cooling strategy and how you implemented it
• any special HVAC system challenges that you encountered

Model Coordination

Upload the latest versions of your architectural, structural, and HVAC models to Autodesk Construction Cloud, then copy these latest versions into your Model Coordination space to explore the integrated design.

• Walk through a merged model view to experience how the architectural, structural, and HVAC designs work together.
• Look for any potential conflicts or issues that require resolution.

Weekly Design Project Check-In

You’ll meet with a member of the teaching team to review your progress and share tips about how to proceed.