Commercial kitchen ventilation is usually associated with extraction—removing heat, grease, smoke and odours from the cooking environment before discharging them outside.
However, some restaurant locations cannot rely on conventional external extract ductwork.
Planning restrictions, building constraints and the surrounding environment can make recirculating ventilation the preferred or only practical solution. In these applications, kitchen air must pass through multiple filtration stages before it can be safely reintroduced.
That places enormous importance on the control system.
The controls must not only operate the fan. They must verify that each filtration stage is performing correctly, compensate for increasing resistance as filters become dirty, identify damaged or missing filters and provide clear maintenance information before air quality is compromised.
For this project, iACS worked with Univent Systems Ltd to develop a bespoke controls solution for a high-capacity Recirculation Tower serving a premium restaurant brand.
The system combined a 7.35kW EC fan, G4 filters, deep HEPA filtration, five carbon filters, intelligent Modbus pressure monitoring, automatic fan compensation and TERA Cloud remote connectivity.
The finished project became more than a successful restaurant installation. It established the control and wiring architecture later adopted by Univent as the baseline for its new Reflow range of commercial recirculation towers.
What This Project Covers
This project demonstrates how iACS delivered:
- Commercial kitchen recirculation controls
- Multi-stage filter monitoring
- Modbus differential-pressure integration
- Dirty, torn and missing filter detection
- Volumetric EC fan compensation
- Carbon-filter lifecycle monitoring
- TERA Cloud remote access
- Remote HMI emulation
- Automatic alarm forwarding
- Factory functional testing
- On-site commissioning
- A repeatable OEM control standard
Table of Contents
- Project Overview
- Why Recirculating Kitchen Ventilation Needs Advanced Controls
- The Recirculation Tower Configuration
- The Limitations of Standard Filter Switches
- The Bespoke iACS Control Solution
- Monitoring G4 and HEPA Filters with Modbus
- Detecting Torn or Missing Filters
- Monitoring Carbon Filters Without Differential Pressure
- Volumetric Fan-Speed Compensation
- TERA Cloud Remote Monitoring
- Factory Testing and Site Commissioning
- The Project Outcome
- From One Project to an OEM Product Standard
- Before and After the iACS Solution
- Why This Project Matters
- Key Capabilities Demonstrated
- Looking for Intelligent Commercial Kitchen Controls?
1. Project Overview
Sector
Hospitality & Leisure
Application
Commercial Kitchen Recirculation Ventilation
Customer
Univent Systems Ltd
End User
A premium celebrity-chef restaurant brand.
Project Timeline
- Quoted and ordered: March 2026
- Site commissioning: 12 May 2026
- Final completion confirmed: 13 May 2026
iACS Scope
- Bespoke control panel design and supply
- Application software
- Modbus sensor integration
- Filter-management logic
- Volumetric fan compensation
- TERA Cloud subscription
- Factory functional testing
- On-site commissioning
- Remote portal handover
Ventilation Equipment
Univent Recirc Tower 1.5 incorporating:
- 7.35kW EC fan
- G4 panel filters
- 300mm-deep HEPA filters
- Five Sitesafe carbon filters
- High-range differential-pressure monitoring
Control Panel
Bespoke iACS control panel IAC0003866, built around a Carel cPCO Small controller.
Project Status
Commissioned, connected and operational.
2. Why Recirculating Kitchen Ventilation Needs Advanced Controls
A conventional kitchen extract system removes contaminated air and discharges it outside.
A recirculating system must do something more demanding: clean the air sufficiently for it to be safely reintroduced.
That means the filtration stages become central to the performance of the entire system.
The controls must provide confidence that:
- Grease is being captured
- Fine particles are being removed
- Odours are being treated
- Filters are present
- Filters are not damaged
- Filters are not excessively blocked
- Airflow remains at the required level
A basic fan starter and dirty-filter alarm cannot provide this level of protection.
The ventilation system needs continuous awareness of its own condition.
3. The Recirculation Tower Configuration
The Recirc Tower 1.5 was designed to move commercial kitchen air through a dense three-stage filtration system.
The main components included:
G4 Panel Filters
The first filtration stage captures larger airborne particles and protects the downstream filters.
HEPA Filters
The 300mm-deep HEPA filters provide fine-particle removal and create a significant resistance to airflow.
Carbon Filters
Five Sitesafe carbon filters absorb odours and gaseous contaminants that cannot be removed through particle filtration alone.
High-Capacity EC Fan
A 7.35kW EC fan was required to overcome the resistance of the complete filter bank while maintaining the design airflow.
The challenge was not simply operating this equipment.
It was ensuring the complete system continued to perform correctly as the filters changed condition over time.
4. The Limitations of Standard Filter Switches
Traditional HVAC systems often use differential-pressure switches.
These devices provide a simple digital status:
- Filter normal
- Filter dirty
Although suitable for many applications, this approach had significant limitations for the recirculation tower.
A switch could indicate that resistance had become too high, but it could not continuously report the actual pressure drop.
More importantly, a standard switch could not reliably identify a filter that had:
- Torn
- Collapsed
- Been removed
- Been installed incorrectly
In these situations, pressure drop may fall rather than rise.
A conventional high-pressure alarm might therefore report that everything was normal while unfiltered air bypassed the system.
For a premium restaurant application, that was not acceptable.
5. The Bespoke iACS Control Solution
iACS designed and manufactured a custom control panel built around the Carel cPCO architecture.
The system combined:
- Programmable filter logic
- EC fan control
- Modbus communications
- Remote HMI access
- Alarm management
- Runtime tracking
- Cloud connectivity
The control strategy was developed specifically around the characteristics of the Recirc Tower rather than adapted from a basic kitchen ventilation program.
This transformed the unit from a collection of fans and filters into a connected, self-monitoring ventilation product.
6. Monitoring G4 and HEPA Filters with Modbus
iACS replaced conventional pressure switches with Belimo Modbus differential-pressure transducers.
The system incorporated 22ADP-154 and 22ADP-156 devices selected to suit the different pressure ranges across the filtration stages.
Rather than returning a simple on/off contact, the transducers transmitted live pressure values digitally to the controller.
This allowed the software to continuously monitor:
- Current filter pressure drop
- Rising resistance
- Rate of filter deterioration
- Abnormally low resistance
- Maintenance thresholds
- Alarm status
Digital Modbus communication also reduced the risk of analogue signal interference and provided more detailed diagnostic information.
7. Detecting Torn or Missing Filters
One of the strongest features of the design was its ability to detect not only blocked filters, but also damaged or missing filters.
The software monitored both the upper and lower limits of the expected pressure range.
Rising Pressure Drop
An increasing pressure drop suggested that the filter was becoming dirty or blocked.
The controller could then generate a maintenance warning before airflow became critically restricted.
Falling Pressure Drop
An unexpected reduction in pressure could indicate:
- A torn filter
- A collapsed filter
- A filter that had been removed
- Air bypassing the intended filtration path
This approach provided protection that would not be possible using a standard dirty-filter switch alone.
It gave operators greater confidence that the filtration system was physically present and functioning, not merely free from blockage.
8. Monitoring Carbon Filters Without Differential Pressure
Carbon filters present a different challenge.
Unlike particle filters, their effectiveness is based on chemical adsorption. A carbon filter can become saturated without producing a reliable change in differential pressure.
For this reason, pressure monitoring alone could not determine when replacement was required.
iACS developed a time-based software strategy.
The controller recorded the actual hours during which the fan was operating and generated a dedicated Replace Carbon Filters alarm after 12 months of accumulated runtime.
This provided a practical maintenance trigger based on real system usage rather than a fixed calendar date.
The solution ensured that:
- Carbon-filter life was actively tracked
- Maintenance was not dependent on memory
- Replacement alerts were generated automatically
- No additional field sensor was required
9. Volumetric Fan-Speed Compensation
As filters become dirty, their resistance increases.
Without compensation, the airflow through the unit would gradually reduce even though the fan command remained unchanged.
To prevent this, iACS developed a volumetric fan-control strategy.
The controller used live pressure information to increase the EC fan demand as filter resistance rose.
This allowed the system to maintain more consistent airflow throughout the filter lifecycle.
Benefits included:
- Stable ventilation performance
- Reduced airflow degradation
- Better air-quality control
- Improved use of filter life
- Fewer manual fan adjustments
The strategy allowed the fan to respond dynamically to the changing condition of the filtration system.
10. TERA Cloud Remote Monitoring
The project included an AirCare TERA Cloud subscription.
A built-in communications solution connected the control panel to the secure remote portal.
This gave Univent’s service team access to:
- Remote HMI emulation
- Live operating values
- Pressure readings
- Fan status
- Filter alarms
- Running hours
- Trend history
- Automatic alarm forwarding
Instead of travelling to site simply to inspect an alarm or verify a reading, engineers could review the system remotely.
This supported faster diagnosis and more proactive maintenance.
The remote portal also allowed the service team to understand how filter resistance developed over time, helping them plan replacement activities more effectively.
11. Factory Testing and Site Commissioning
Before delivery, the bespoke control panel underwent a full functional test.
The test process verified:
- Controller operation
- Fan outputs
- Modbus communications
- Pressure-transducer readings
- Alarm thresholds
- Runtime logic
- Cloud connectivity
- General panel operation
An iACS commissioning engineer then attended site on 12 May 2026.
The commissioning activities included:
- Control panel inspection
- EC fan startup
- Filter sensor verification
- Pressure range checks
- Fan balancing
- Alarm testing
- Runtime alarm verification
- TERA Cloud activation
- Remote login handover
Following completion, the panel was fully operational and the TERA Cloud access details were handed over to Univent.
12. The Project Outcome
The final solution delivered:
- Continuous G4 filter monitoring
- Continuous HEPA filter monitoring
- Dirty-filter detection
- Torn-filter detection
- Missing-filter detection
- Carbon-filter replacement alarms
- Automatic fan compensation
- Stable system airflow
- Remote HMI access
- Live trend logging
- Automatic alarm forwarding
- Successful factory and site commissioning
The result was an intelligent recirculation system capable of monitoring both its performance and its maintenance condition.
13. From One Project to an OEM Product Standard
The value of the project extended beyond the original restaurant installation.
Following its successful delivery, Univent adopted the same iACS control philosophy and wiring architecture as the baseline standard for its new Reflow range of commercial recirculation towers.
This demonstrates that the project achieved more than a one-off solution.
It created:
- A repeatable control platform
- A standard wiring approach
- A proven filter strategy
- A scalable remote-monitoring model
- A stronger OEM product proposition
By working closely with Univent, iACS helped turn a project-specific requirement into a reusable commercial product architecture.
14. Before and After the iACS Solution
| Traditional Approach | iACS Intelligent Solution |
| Simple dirty-filter switches | Live Modbus pressure monitoring |
| Blockage detection only | Dirty, torn and missing-filter detection |
| Fixed fan speed | Automatic volumetric compensation |
| Manual carbon-filter tracking | 12-month runtime alarm |
| Local access only | TERA Cloud remote HMI |
| Reactive maintenance | Alarm forwarding and trend analysis |
| One-off panel design | Adopted as an OEM product standard |
15. Why This Project Matters
This project demonstrates that advanced HVAC controls are not limited to temperature regulation.
In specialist kitchen recirculation systems, controls play a direct role in air-quality protection.
By combining pressure transducers, runtime logic, EC fan compensation and cloud connectivity, iACS created a system capable of understanding its own condition and alerting operators before performance was compromised.
The project also shows the wider value of a close OEM partnership.
Rather than merely supplying a control panel, iACS worked with Univent to create a repeatable control architecture that could support an entire future product range.
16. Key Capabilities Demonstrated
- Commercial kitchen recirculation controls
- Multi-stage filtration monitoring
- Belimo Modbus pressure-transducer integration
- Torn and missing-filter detection
- Carbon-filter runtime alarms
- Volumetric EC fan compensation
- Carel cPCO programming
- TERA Cloud connectivity
- Remote HMI emulation
- Factory functional testing
- Site commissioning
- OEM control-platform development
17. Looking for Intelligent Commercial Kitchen Controls?
Whether you are developing a new recirculation unit, upgrading an existing kitchen ventilation system or looking to introduce remote monitoring across your product range, iACS can help.
Our capabilities include:
- Commercial kitchen control panels
- Recirculation ventilation controls
- Advanced filter monitoring
- EC fan control
- Modbus sensor integration
- Cloud connectivity
- Remote alarm monitoring
- OEM product development
- Factory testing
- Site commissioning
- Long-term technical support
From individual restaurant installations to complete OEM product platforms, iACS delivers intelligent controls that improve visibility, protect air quality and simplify ongoing maintenance.