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How to Use the Rubix Air Handling Unit Selection Tool: A Complete Guide

Learn how to use the Rubix AHU Selection Tool to configure Air Handling Unit controls, generate quotations, produce technical documentation and streamline HVAC project delivery.
July 7, 2026 by
How to Use the Rubix Air Handling Unit Selection Tool: A Complete Guide
Peter Campbell

Selecting HVAC controls for an Air Handling Unit (AHU) can often be one of the most time-consuming parts of a project.

Engineers need to determine the correct control strategy, identify every field device, specify hardware, generate technical documentation, produce quotations, prepare wiring information and ensure the control philosophy matches the mechanical design.

Traditionally, much of this process has been completed manually.

At iACS, we wanted to change that.

That's why we developed Rubix, an intelligent AHU selection and configuration platform that dramatically reduces engineering time while improving consistency across every project.

Rather than manually creating every document from scratch, Rubix allows users to configure an AHU using an intuitive selection interface before automatically generating technical documentation, quotations and engineering outputs.

Whether you're configuring a simple ventilation unit or a complex healthcare Air Handling Unit, Rubix provides a faster, more consistent and more intelligent way to specify HVAC controls.


What This Blog Covers

In this guide you'll learn:

  • What Rubix is
  • Who it's designed for
  • How to create a project
  • How to configure an Air Handling Unit
  • Every major selection available within Rubix
  • The documentation Rubix generates
  • The benefits of using Rubix
  • How Rubix supports the wider iACS project workflow


Table of Contents

  1. What is Rubix?
  2. Why Was Rubix Developed?
  3. Who Uses Rubix?
  4. Creating a New Project
  5. Selecting the Right Control Panel
  6. Define the Physical AHU
  7. Fan Configuration
  8. Heating & Cooling Selection
  9. Heat Recovery Selection
  10. Dampers & Actuators
  11. Humidification
  12. Filters & Monitoring
  13. Additional Control Features
  14. BMS Integration
  15. Remote Displays
  16. Generating Technical Documentation
  17. Why Rubix Saves Time
  18. Frequently Asked Questions
  19. Conclusion: Discover How Rubix Can Transform Your Next HVAC Project


1. What is Rubix?

Rubix is iACS's intelligent AHU selection and configuration platform.

It has been developed to simplify one of the most complex stages of any HVAC controls project: selecting the correct control strategy and generating all associated engineering documentation.

Instead of manually calculating inputs, outputs and hardware requirements, Rubix allows engineers to answer a series of guided questions about the Air Handling Unit.

The software then automatically generates the required documentation based on those selections.



2. Why Was Rubix Developed?

Every Air Handling Unit is different.

Some units contain:

  • Two fans

Others contain:

  • Eight EC fans
  • Heat recovery
  • DX cooling
  • Humidification
  • Gas heating
  • Multiple dampers
  • Building Management System integration

Manually selecting every component increases engineering time and introduces opportunities for inconsistency.

Rubix was developed to standardise this process.

By following a structured workflow, engineers can configure an AHU in minutes rather than hours while ensuring every selection follows the latest iACS engineering standards.



3. Who Uses Rubix?

Rubix has been designed for:

  • AHU Manufacturers
  • HVAC Contractors
  • Consultants
  • Controls Engineers
  • Sales Engineers
  • Estimators
  • Project Engineers
  • Commissioning Teams

Whether you're pricing a new project or preparing it for manufacture, Rubix simplifies the process.



4. Create a New Project  

Every project begins by creating a new project within Rubix.

Users simply enter:

  • Project name
  • Site location
  • Installation costs (if required)
  • Commissioning costs (if required)

Once the project has been created, individual Air Handling Units can be added and configured independently.

This allows multiple AHUs to exist within the same project while maintaining consistent documentation throughout.

 
Configure Your Air Handling Unit

Each AHU is configured individually.

Users simply create the unit name before entering the selection wizard.

For example:

  • AHU01
  • AHU02
  • AHU03

Every unit can later be duplicated, allowing engineers to quickly create multiple similar AHUs without repeating the entire configuration process.

This is particularly useful on projects containing numerous units with only minor variations.



5. Selecting the Correct Control Panel

One of the first decisions is selecting the appropriate iACS control platform.

Rubix currently supports:

  • iX
  • iX Compact
  • iX HTM
  • iSmart
  • iSmart HTM
  • Compact Panels

Engineers can then choose:

  • Enclosure
  • Backplate only
  • Anti-condensation heaters
  • Internal lighting supplies

This immediately establishes the foundation for the entire controls package.



6. Define the Physical AHU

The Air Handling Unit was configured for volume control using EC fans.

Commissioning verified:

  • 0–10V control signals
  • Fan enable outputs
  • Alarm relays
  • Fan rotation
  • Air volume setpoints

Both supply and extract fans were configured for 18 m³/s airflow with matching K-factors, ensuring balanced system operation.



7. Fan Configuration

Fan selection is one of the most comprehensive areas within Rubix.

Users can specify:

  • Supply fans
  • Extract fans
  • Number of fans
  • Fan manufacturer
  • Motor size
  • EC or AC motors
  • Single or three phase
  • Inverter requirements

For AC motors, Rubix allows engineers to select inverter protection levels and whether inverters should be supplied with the project.

This ensures the control system is correctly matched to the mechanical equipment.


Intelligent Fan Control Strategies

Rubix supports multiple fan control philosophies.

These include:

Fixed Speed: Fans operate continuously at a commissioning-adjusted speed.

Pressure Control: Fans modulate to maintain duct pressure.

Volume Control: Airflow is automatically maintained using fan K-factors.

Air Quality Control: Fans respond to CO₂ levels.

Temperature Control: Fan speed adjusts according to temperature demand.

Each strategy is accompanied by an explanation, helping engineers select the most appropriate solution for the project.



8. Heating & Cooling Selection

Rubix supports a wide variety of HVAC heating and cooling strategies.

Heating options include:

  • Electric heaters
  • Gas heaters
  • LPHW coils
  • Frost coils
  • Main heating coils
  • Reheat coils

Cooling options include:

  • Chilled water
  • DX cooling
  • Heat pumps
  • Dehumidification

Engineers can also specify:

  • Valve types
  • Water flow rates
  • Pressure drops
  • IP ratings
  • Coil splitting
  • Heater staging
  • Thyristor control

This allows Rubix to generate an accurate control solution tailored to the mechanical design.



9. Heat Recovery Selection  

Modern AHUs increasingly incorporate heat recovery.

Rubix currently supports:

  • Thermal Wheels
  • Cross Flow Heat Exchangers
  • Run Around Coil Systems

Depending on the selection, Rubix automatically requests the information required to size actuators, control strategies and associated hardware.

This ensures every heat recovery solution is configured correctly from the outset.



10. Dampers & Actuators

Rubix allows complete damper configuration including:

  • Fresh air dampers
  • Exhaust dampers
  • Mixing dampers
  • Supply dampers
  • Return dampers

Engineers can specify:

  • Damper size
  • Number of spindles
  • Fail-safe actuators
  • End switches
  • IP ratings
  • Terminal connections

Rather than manually selecting actuators later, Rubix incorporates these requirements directly into the project.



11. Humidification  

The software supports both:

  • Steam humidifiers
  • Adiabatic humidifiers

Additional selections include:

  • High limit humidistats
  • Power supplies
  • Single-phase
  • Three-phase

Rubix automatically adjusts the control philosophy depending on the humidification strategy selected.



12. Filters & Monitoring

Filter monitoring is fully configurable.

Engineers can select:

  • Panel filters
  • Supply bag filters
  • Return bag filters
  • HEPA filters

Each filter can be monitored using either:

  • Differential pressure switches
  • Pressure transducers

Rubix also allows common or individual alarm monitoring depending on project requirements.



13. Additional Control Features

Rubix includes numerous additional control options including:

  • Fire alarms
  • Fireman's override
  • Remote start/stop
  • Room temperature sensors
  • Averaging sensors
  • Setpoint adjusters
  • Expulsion temperature sensors
  • Fresh air sensor types

These options allow engineers to tailor the control strategy to virtually any Air Handling Unit configuration.



14. Building Management System Integration

Building Management System integration is increasingly important.

Rubix currently supports:

  • BACnet IP
  • BACnet MSTP
  • Modbus RTU
  • Modbus TCP/IP

This allows engineers to prepare controls that integrate seamlessly into wider building automation systems.



15. Remote Displays

Large logistics facilities demand HVAC systems that are reliable, maintainable and capable of continuous operation.

This project demonstrates how iACS combines intelligent controls, bespoke engineering and structured commissioning to deliver systems that are ready for long-term operation.

Rather than simply manufacturing control panels, iACS provides complete HVAC controls support throughout the project lifecycle.



16. Automatically Generated Documentation

Perhaps the biggest benefit of Rubix is the documentation it produces.

At the click of a button, Rubix can generate:

  • Technical datasheets
  • Costed quotations
  • Bills of Materials (BOM)
  • Description of Operation
  • Input & Output schedules
  • BMS points lists

Rather than creating these documents manually, engineers receive consistent documentation generated directly from the AHU configuration.



17. Why Rubix Saves Time 

Rubix significantly reduces engineering effort by:

  • Eliminating repetitive data entry
  • Standardising selections
  • Reducing engineering errors
  • Automatically generating documentation
  • Simplifying quotations
  • Speeding up project delivery

For manufacturers managing multiple AHUs across large projects, these efficiencies can save many hours of engineering time.

How Rubix Fits into the iACS Workflow

Rubix is one part of the wider iACS digital ecosystem.

Once an AHU has been configured, projects can move seamlessly into:

  • Production
  • Manufacturing
  • Panel testing
  • Installation
  • Commissioning
  • Documentation
  • NEXUS project management

This creates a streamlined workflow that supports every stage of an HVAC controls project.



18. Frequently Asked Questions

Is Rubix only for Air Handling Units?

Rubix has been developed specifically for AHU control system selection, allowing engineers to configure a wide range of ventilation and HVAC applications.

Does Rubix generate quotations?

Yes. Rubix can generate costed datasheets and quotations directly from the AHU configuration.

Can multiple AHUs be configured?

Yes. Multiple AHUs can be created within the same project, duplicated and individually customised.

Does Rubix generate BMS points lists?

Yes. Rubix automatically generates BMS points lists along with several other engineering documents.

Who should use Rubix?

Rubix is designed for manufacturers, consultants, contractors, controls engineers, project engineers and commissioning teams looking to streamline HVAC controls design.



Discover How Rubix Can Transform Your Next HVAC Project 

Rubix has transformed the way HVAC controls are configured at iACS.

By combining intelligent configuration with automated documentation, the platform allows engineers to move from concept to quotation in significantly less time while improving consistency across every project.

Whether you're configuring a single Air Handling Unit or managing a large multi-unit development, Rubix provides a faster, smarter and more reliable approach to HVAC controls selection.

If you're looking to reduce engineering time, improve quotation accuracy and simplify the configuration of Air Handling Unit controls, Rubix provides a powerful solution built specifically for the HVAC industry.

Combined with iACS's manufacturing, installation, commissioning and software expertise, Rubix helps deliver complete HVAC control solutions from initial concept through to project handover.

Contact the iACS team today to arrange a demonstration and discover how Rubix can transform the way you specify and deliver HVAC controls.

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