Interactive AHU Simulator
Use the interactive AHU simulator to experiment with supply temperature, duct pressure, occupancy, CO₂, outdoor temperature, filter conditions and HVAC control sequences.
The LumiBMS AHU Simulator models a complete air handling unit with supply and extract air paths, heat recovery, heating and cooling coils, pressure controlled fans and room conditions.
Change operating conditions and watch how the building automation control sequence responds in real time.
What does the AHU simulator model?
The simulator includes:
- outdoor air damper
- supply air filter
- rotary heat recovery
- heating coil
- cooling coil
- supply fan
- extract fan
- supply duct pressure
- extract duct pressure
- room temperature
- room CO₂
- occupancy
- filter pressure drop
- PI control
- alarms
How does the AHU control sequence work?
Outdoor air enters through the intake damper and filter. Heat recovery transfers energy between the extract air and incoming outdoor air before the heating and cooling coils regulate the supply air temperature.
The supply and extract fans regulate duct pressure using PI control. Room temperature, occupancy and CO₂ create changing loads that affect heating, cooling and ventilation demand.
Supply air temperature control
The controller compares the measured supply air temperature with its setpoint.
Heat recovery is used when useful energy can be transferred from the extract air. Heating or cooling output is then adjusted to reach the requested supply air temperature.
Duct pressure control
The supply and extract fans regulate their respective duct pressure setpoints.
When system resistance changes, for example because filters become dirty, the fan controllers adjust their outputs to maintain the required pressure.
Room temperature and CO₂
The room model reacts to supply air conditions, outdoor temperature and occupancy.
Increasing occupancy adds internal heat and increases CO₂ generation. Changes in ventilation affect how quickly the room conditions respond.
Try these AHU simulation scenarios
Cold winter conditions
Set the outdoor temperature to approximately -15 °C and observe heat recovery and heating demand.
High occupancy
Increase occupancy and observe the effect on room temperature and CO₂ concentration.
Dirty filters
Increase filter dirtiness and observe filter pressure drop and fan response.
Change the supply air temperature setpoint
Change the supply temperature target and observe how the PI controller changes heating and cooling output.
What can the AHU simulator be used for?
The simulator can be used for:
- building automation training
- HVAC control education
- learning AHU operating sequences
- understanding PI control
- testing disturbances and setpoint changes
- demonstrating heat recovery
- explaining duct pressure control
- understanding how sensors and actuators interact
Frequently asked questions
What is an AHU?
An air handling unit, or AHU, conditions and circulates air in a building. Typical components include filters, heat recovery, heating and cooling coils, dampers and fans.
How does an AHU control supply air temperature?
The controller compares measured supply air temperature with its setpoint and adjusts heat recovery, heating and cooling output to reduce the temperature error.
Why does an AHU control duct pressure?
Duct pressure control allows the fans to adapt to changing airflow demand and system resistance while maintaining suitable pressure in the ventilation system.
What does heat recovery do?
Heat recovery transfers thermal energy between extract air and incoming outdoor air. This can reduce heating and cooling demand.
What happens when AHU filters become dirty?
Dirty filters create a larger pressure drop. A pressure controlled fan may increase its output to maintain the requested duct pressure.