Systems

Systems in HVAKR represent the HVAC equipment that conditions your building. Each system includes central equipment and serves one or more zones.

System Concepts

What is a System?

A system includes:

Central unit - AHU, RTU, or other central equipment
Terminal units - VAV boxes, fan coils, etc.
Ductwork - Air distribution network
Zones - The spaces being served

System Types

Common system configurations:

Single-zone - One thermostat controls the entire system
Multi-zone - Multiple zones with terminal units
VAV - Variable air volume with zone control
VRF - Variable refrigerant flow

Creating Systems

Automatic System Creation

HVAKR can automatically create systems from unassigned zones:

Navigate to Building Model > Systems
Click Auto Group Zones (the wand icon) in the toolbar
HVAKR creates systems and groups unassigned zones into them immediately — there is no strategy dialog — and shows a toast with how many systems were created and zones grouped
Review the results on the canvas and adjust zone assignment as needed

Create a System

Navigate to Building Model > Systems
In the Systems panel, click Create System (or press N)
A new system named New System is added and selected automatically
Rename it and set its color in the System Data panel
Assign zones to the system (see below)

Systems are created empty — there is no system-type template to pick at creation. Configure the central unit, coils, and outdoor air afterward in the System Design > Configuration pane.

Assigning Zones

Assign Zones to a System

Select a system in the Systems panel
In the System Data panel, click Assign Zones
Click zones on the canvas to toggle their assignment — the hint bar reads Click a zone to toggle system assignment
Assigned zones appear in the system’s Zones list; remove one with the ✕ button
Click Done when finished

Zone Requirements

When zones are assigned:

Airflow is calculated based on zone loads
Terminal units are sized
Ventilation is distributed to zones

System Capacity

The system calculates total capacity based on:

Sum of zone peak loads (with diversity)
Ventilation requirements
Safety factors

System Data

Select a system in the Systems panel to edit it in the System Data panel:

Name - Rename the system
Total Area - Combined floor area of the system’s spaces (read-only)
Color - Display color for the system on the canvas
Zones - The zones assigned to the system (see Assigning Zones); click a zone to open it
Occupancy Diversity, Lighting Diversity, and Equipment Diversity - Diversity factors applied to the system’s occupancy, lighting, and equipment gains when aggregating zone loads
Preview Loads - Show the system’s aggregated load summary
Delete - Remove the system

The central unit, terminal units, coils, outdoor air, and duct parameters are not set here — configure them in the System Design > Configuration pane, using the project’s duct types for duct sizing.

System Calculations

Load Aggregation

System load combines zone loads:

Sensible cooling load
Latent cooling load
Heating load
Ventilation load

Airflow Calculation

Supply airflow based on:

Peak sensible load
Supply air temperature
Minimum ventilation

Equipment Sizing

Size central equipment for:

Peak system load
Coincident outdoor air
Part-load performance

Multiple Systems

System Per Floor

Common approach:

Separate AHU for each floor
Easier maintenance access
Simpler duct routing

System Per Exposure

Alternative approach:

Interior system (cooling only)
Perimeter systems (heating and cooling)
Better load matching

Central Plant

For large buildings:

Central chiller plant
Central boiler plant
Systems connect to plant loops

Best Practices

Match system to building - Use appropriate system types
Consider maintenance - Accessible equipment locations
Plan for future - Size systems with growth capacity
Check diversity - System capacity vs. sum of zones
Verify ventilation - Adequate outdoor air for all zones