Introducing: HVAC Distributions and Multiplication

Setting up HVAC systems for multi-storey buildings has traditionally meant a lot of repetition. Draw an air loop, connect the terminals, maybe tag by level, repeat for each floor. Our new Distributions and Multiplication features exist to handle some of that tedium for you.

These two features work together. Distributions define the structural pattern of how your HVAC system repeats and reconnects across the building. Multiplication defines how many instances of each component actually get created. Together, they let you draw a system once and have it scale to whatever the building requires.

Distributions

A distribution tells Better Building: "This branch of my HVAC tree repeats for each zone group I've defined." Groups might represent floors, building wings, or orientations (north/south perimeter). The grouping is yours to decide.

The workflow is straightforward:

1. Create Groups (Level 1, Level 2, Level 3)

2. Assign Zones to those Groups

3. Mark HVAC components as belonging to a distribution

4. The system replicates those components per group when the model processes

What you see in the interface is a clean schematic showing the pattern. Components are colour-coded by distribution group, making it easy to see which elements belong together. This also helps with validation: if a blue component connects to a green component with a gap between them, something's misconfigured.

What gets written to the EnergyPlus IDF is the fully expanded system with every instance connected appropriately.

Multiplication Logic

Distributions define structure. Multiplication logic controls instance counts per component. For example, you might want to replicate a component for every thermal zone in its scope, which is standard for air terminals (58 zones might mean means 58 terminals). Or you may need to replicate each connection such as a air handling unit or chilled water loop to serve the air terminals below it.

Combining Modes

The flexibility comes from mixing modes. A typical configuration:

Component	Mode	Result (5 floors, 58 zones)
Air terminals	Per zone	58
Air handling units	Per group	3
Hot water loop	Per group	3
Chilled water loop	Common	1
Chillers	Common	As defined

Each component follows its own rule. The system maintains connections between them. Every terminal connects to its floor's AHU. Every AHU connects to the common chilled water loop.

Why This Matters?

The air side of HVAC modelling is where complexity tends to accumulate. More zones, more terminals, more connections than the plant side. Distributions and multiplication logic let you manage that complexity at the pattern level rather than the instance level.

You describe the intent once. Better Building handles the replication. When the design changes (and it will), you're updating a pattern rather than chasing individual components across dozens of zones. It's a more sustainable way to work, and one that scales with project complexity instead of fighting against it.