HyPerformance Upgrade in a High School, France

The Antoine Corriere high school in the south of France decided to renovate its heating system with the aim of reducing energy consumption. The choice to renovate came in response to a government funding program of 4bn€ for renovation of state-owned buildings.

The renovation focused on the primary side of the central heating system that services all seven buildings. To access the government funding the renovation requirements included putting in place systems capable of measuring, managing, and controlling energy consumption within the building.

All seven buildings have multiple floors and host different applications, which therefore require different load profiles. The dormitory, for instance, is pumping higher loads mornings and evenings, while classrooms are more utilized during the day. Also, the sport hall and the restaurant require higher peak loads. The piping network is also extensive and therefore the pressure losses are significant.

As part of the renovation, they wanted to be able to know the energy distribution throughout the system. This data would enable the facility management team to adjust heat distribution control, reduce energy consumption, and lower the carbon footprint while guaranteeing comfort.

Aware of the impact of water quality and pressurisation, the customer wanted to prevent any equipment failures and preserve the installation’s life with quality equipment. The reliability of the equipment vital for occupant comfort and well-being in educational buildings. And the fact they could source all these solutions from an unique supplier which limits the discussion related to accountability and liability was a big selling point.

The renovation of the primary side of the central heating room included:

• New boilers, including a gas boiler of 500kW and a wood boiler of 250kW.
• To safeguard system reliability the high-quality Compresso Connect pressurisation equipment was installed
• Adjustment of the distribution up to the heat exchangers and to ensure that the proper amount of energy is conveyed to the required spaces at any time balancing of the circuit was fundamental.
• Installation of TA-Smart valves and temperature sensors

While the HVAC designer dimensioned the piping network, the IMI Hydronic representative calculated the valve sizing, pressurisation, and water quality equipment using HySelect, helping the consultant ensure his calculation was correct and providing them peace of mind. The valves selected have an EQM characteristic which considers the non-linearity of the heat exchanger characteristic.

Once the product was received, it was mounted on the skids, i.e., prefabricated units for heat exchangers connected to the piping network on-site.

In order to meet the funding demands and measure the energy consumed by the subcircuits at each heat exchanger, the choice of the TA-Smart control valve which continuous measurement capabilities on temperature, flow, and power was installed. The high flow capacity of TA-Smart enabled the customer to reduce its costs by picking a valve one-dimension smaller than the pipe size. A secondary temperature probe was mounted on the supply of the primary circuit.

The commissioning of the installation has been done in cooperation with the system integrator and the commissioning company. A hybrid configuration was chosen for reliability and troubleshooting purposes (0-10V control, feedback via Modbus RTU).

• Control Principle:  TA-Smart was set to function on flow control mode, depending on the supply temperature of the secondary side. The flow is controlled through a 0-10V signal, defined by the secondary side’s supply temperature. All the parametrisations have been done via the mobile application HyTune.
• Measure: The key hydronic parameters are measured by TA-Smart and communicated via Modbus RTU to the BMS.
• Operation:  The TA-Smart valves control the flows and regularly feed data back to the BMS. The valve closest to the pump needs to absorb up to 3 bars of differential pressure but still controls with great accuracy even at low flow regimes. “It is so great that we can set up everything with the mobile app not requiring any additional material.” Commission engineer.

IMI Hydronic Engineering's contribution to this project was twofold. Firstly, through our cutting-edge digital product portfolio, with latest TA-smart valve that seamlessly integrates accurate control and measurement capabilities in one solution, along with user-friendly apps and software. Secondly, our expert technical support was instrumental in assisting the HVAC designer and BMS integrator in selecting the right products, ensuring correct installation and commissioning, and achieving optimal performance for the system.