Unlocking Potential: Retrofitting Legacy BMS with VEXO's IoT Devices

In an era where energy efficiency and smart technology integration are paramount, retrofitting legacy Building Management Systems (BMS) with advanced IoT devices stands at the forefront of our energy saving solutions. These IoT sensors and controls are being increasingly deployed across various building types and sizes, transforming them into intelligent spaces that optimise energy usage, ensuring significant gas and energy savings. The shift towards integrating IoT devices into BMS highlights the industry’s move towards more sustainable, cost-effective, and efficient operations.

This blog is based on the paper presented by Richard Fargus and Darren Wilkinson at the CIBSE Technical Symposium 2024 and delves into the intricacies of upgrading traditional BMS with VEXO’s LoRaWAN IoT devices. Click play to watch the entire session below.

Understanding Legacy BMS

Legacy Building Management Systems (BMS) are often characterised by their centralised control strategies, which are crucial in managing the environmental conditions within large buildings. These systems typically involve compensated Variable Temperature (VT) circuits that operate continuously throughout the year, reflecting a traditional approach to building temperature regulation.

Centralised Control Strategy

Continuous Operation: Legacy BMS are designed to run compensated VT circuits all year round, regardless of actual demand or external weather conditions. This often results in inefficiencies and higher energy consumption.
Limited Flexibility: The centralised nature restricts quick adaptability to changes in building usage or external environmental changes, making it less efficient compared to modern systems.

Somerset House, a notable example, integrates a bivalent heating system that combines a Combined Heat and Power (CHP) system with gas boilers. This setup distributes heat across the building via six VT circuits. Despite the integration of advanced systems like CHP, the heating efficiency is compromised by the lack of individual control at the radiator level.

Case Study: Somerset House

Heating System: Utilises a combination of CHP system and gas boilers.
Heat Distribution: Heat is distributed through six VT circuits, designed to cover extensive areas without individual control.

In older setups like that of Somerset House, most radiators lacked thermostatic controls. This absence meant that temperature regulation within different zones of the building was largely ineffective, leading to discomfort and wasted energy. The need for flow temperature trimming arose as a manual method to somewhat mitigate this issue, yet it remained a cumbersome and imprecise solution.

Thermostatic Control Limitations

Lack of Individual Controls: Most radiators did not feature individual thermostatic controls, leading to inefficient heating and increased energy usage.
Manual Adjustments: Flow temperature trimming was often required to manually adjust temperatures, a method that lacks precision and efficiency.

Understanding these foundational aspects of legacy BMS provides a clear perspective on the potential enhancements that IoT devices can offer, particularly in terms of energy efficiency and operational control. To address these challenges, Somerset House underwent a major heating system upgrade. The upgrade involved the installation of approximately 350 VEXO S-IoT room temperature and motion sensors, along with 750 LoRaWAN wireless digital Thermostatic Radiator Valves (TRVs), thereby creating 350 independent control zones.

We are currently seeing around 30% of gas savings compared to other base years, which means a payback period between five and six years, which is fairly short, for the size of the building.

Mick Figg

Head of Buildings, Somerset House

The Role of IoT in Enhancing BMS

Integrating IoT devices into legacy Building Management Systems (BMS) revolutionises control strategies by enabling precise, zone-specific management. This shift significantly enhances energy efficiency and occupant comfort through the following mechanisms:

Zonal Control Strategy

Occupant-Driven Control: IoT-enabled BMS can dynamically adjust heating, cooling, and lighting based on real-time occupancy data, ensuring energy is used only when needed.
Demand-Driven Operation: Each zone operates based on actual demand rather than predefined schedules, which reduces energy waste and optimises resource use.

IoT devices facilitate a seamless integration with existing BMS infrastructure, utilising protocols like LoRaWAN to ensure robust, secure communication between sensors, actuators, and control systems. This integration supports a more granular control over building environments, adapting in real-time to changes in occupancy and environmental conditions.

Enhanced Monitoring and Control

Wireless Sensors and Actuators: Deploying wireless IoT devices across a building allows for the monitoring and control of environmental conditions in numerous zones without the need for extensive rewiring.
Real-Time Data Utilisation: IoT sensors provide continuous data that BMS can use to adjust parameters instantly, enhancing the overall efficiency of the system.

The deployment of IoT devices not only supports current operational needs but also scales to accommodate future expansions or reconfigurations of building spaces. This adaptability is crucial for buildings undergoing frequent layout changes or those with variable occupancy patterns.

Cost-Effectiveness and Energy Savings

Reduced Installation Costs: Wireless IoT devices are less costly to install compared to traditional wired systems, as they require minimal structural changes and can be easily integrated into existing networks.
Significant Energy Reduction: By focusing on active zones and reducing energy consumption in unoccupied areas, IoT-enhanced BMS can achieve substantial energy savings, directly impacting operational costs and environmental footprint.

The strategic deployment of IoT devices within BMS frameworks not only elevates the functionality of legacy systems but also aligns with sustainability goals by reducing energy use and CO2 emissions. This integration exemplifies how modern technology can retrofit older systems to meet contemporary standards of efficiency and environmental care.

Retrofitting Process and Considerations

Detailed Energy Analysis and Savings

Energy Consumption Reduction: Studies have shown that retrofitting BMS with IoT controls can lead to significant reductions in energy use. For instance, a larger site experienced a 25.4% decrease in gas consumption and a 36.9% reduction in heating energy use, demonstrating the substantial impact of targeted energy delivery.
Boiler Efficiency: Preliminary analyses indicate that boiler gas energy usage can drop by as much as 30% following a retrofit, highlighting the effectiveness of IoT integration in optimizing existing systems.

Cost Considerations and Wireless Solutions

Cost of Wired vs. Wireless Controls: The installation of wired control points, including labor and materials, can cost between £500 and £800 per point. This expense is often prohibitive, making wireless controls a more viable and cost-effective option, especially for extensive systems requiring numerous control zones.
Advantages of Wireless Controls: Wireless field controls not only reduce initial installation costs but also offer flexibility in system design, allowing for the easy addition of numerous control zones without significant disruption or additional expense.

Implementing Zonal Control for Enhanced Efficiency

Necessity of Zone-Level Installation: To achieve effective zonal control, it is essential to install sensors and actuators at the zone level. This allows for precise monitoring and management of environmental conditions, leading to enhanced energy efficiency.
Dynamic Heat-Network Reconfiguration: By integrating occupant and demand feedback, the heat network can dynamically adjust, ensuring that only areas with active demand receive heating. This approach can drastically reduce energy wastage and improve overall system efficiency.

Case Studies and Benefits

Hybrid BMS/IoT Control System Impact

Significant Energy Savings: The integration of IoT devices into legacy BMS has led to remarkable energy savings across various installations. One notable example is the adoption of a hybrid BMS/IoT control system, which has demonstrated a reduction in energy consumption by up to 36% in some cases. This substantial decrease highlights the effectiveness of IoT devices in enhancing the operational efficiency of building management systems.
Operational Efficiency: By implementing IoT-based controls, facilities have observed not only a reduction in energy use but also enhanced precision in environmental management. This precision allows for better temperature and lighting control, contributing to a more comfortable and productive indoor environment for occupants.
Cost Savings: The decrease in energy consumption directly translates into cost savings for building operators. The initial investment in IoT technology is quickly offset by the reduced operational costs, making the retrofit a financially viable option for many businesses.

Enhanced Monitoring and Predictive Maintenance

Real-Time Data Analysis: IoT sensors provide continuous monitoring and data collection, which is crucial for predictive maintenance and operational adjustments. This capability ensures that all systems operate at peak efficiency, reducing the likelihood of unexpected breakdowns and extending the lifespan of the equipment.
Preventative Actions: With advanced analytics, potential issues can be identified and addressed before they escalate into costly repairs. This proactive approach not only saves money but also avoids downtime, enhancing overall building operations.

Environmental Impact and Sustainability

Reduction in Carbon Footprint: The energy savings achieved through IoT integration significantly reduce the carbon footprint of buildings. This is particularly important for companies aiming to meet sustainability goals and comply with environmental regulations.
Support for Green Building Standards: Many modern buildings aim to achieve certifications such as LEED or BREEAM. Integrating IoT into BMS can contribute points towards these certifications, reflecting an investment in sustainable building practices that benefit both the environment and building occupants.

Conclusion

Retrofitting legacy Building Management Systems with VEXO’s IoT devices marks a significant shift towards creating more sustainable, efficient, and occupant-friendly environments. The inherent benefits, as thoroughly explored through various case studies including Somerset House, demonstrate not only a pronounced reduction in energy consumption and operational costs but also an enhancement in the overall comfort and functionality of buildings. This seamless integration of technology with existing infrastructure brings into sharp focus the tangible improvements in energy management, paving the way for a smarter, greener future in building operations.

The broader implications of such technological advancements underscore the potential for drastic improvements in environmental sustainability and operational efficiency. The significant energy and cost savings achieved through IoT retrofitting serve as a steadfast reminder of the importance of modernising legacy systems to meet contemporary standards.

Moreover, this progression towards intelligent building management systems suggests a promising avenue for further research and innovation, encouraging building operators and stakeholders to explore and embrace IoT solutions as a means to not only optimise their operations but also contribute towards global sustainability goals.

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