System Design Overview
The System Design section is where you configure your HVAC systems, balance space airflows, and design duct layouts.
Sections
Section titled “Sections”Configuration
Section titled “Configuration”Set up central unit and terminal unit equipment:
- Central unit capacity and airflow
- Terminal unit types and sizing
- Supply air temperatures
- Control strategies
Air Balancing
Section titled “Air Balancing”Balance each space’s airflows:
- Design supply, return, and exhaust
- Outdoor air delivered directly to the space
- Transfer air in and out
- The resulting differential, with a warning when the space is out of balance
Layout
Section titled “Layout”Design the duct distribution system:
- Register, terminal unit, and central unit placement
- Duct and riser routing and sizing
- Fitting loss coefficients — HVAKR places the fittings themselves
- Critical path and pressure calculations
Workflow
Section titled “Workflow”The typical system design workflow:
- Configure - Set central unit and terminal parameters
- Balance - Adjust per-space supply, return, exhaust, and transfer airflows
- Layout - Route ducts and size components
Each step builds on the previous, so work through them in order.
System Configuration
Section titled “System Configuration”Before designing ductwork:
- Verify system loads are accurate
- Set appropriate supply air temperature
- Configure outdoor air requirements
- Select terminal unit types
Design Validation
Section titled “Design Validation”Run the project Check to validate your design — ask AI Chat to “Check this project,” or run a check job via the REST POST /projects/{id}/jobs endpoint. Check’s design-quality checks include:
- Airflow balance — central unit and terminal (zone) supply vs. return/exhaust
- Equipment oversizing — coil capacity flagged when it’s more than 200% of peak load
- CFM/ton ratio outside the expected 300–500 range
- Duct heat gain coverage against the ceiling-plenum cooling load
Best Practices
Section titled “Best Practices”- Finalize loads first - Complete building model before system design
- Work system by system - Focus on one system at a time
- Check air balance - Verify supply equals return plus exhaust
- Validate equipment - Confirm selected equipment meets requirements
- Document assumptions - Note design decisions for future reference