A digital twin of a building at the University of Liverpool is improving operational energy performance and assessing the impact of an implemented HVAC refurbishment.

The university is the first project to use the Live tool from UK firm IES. This connects live data from a building’s BMS, energy meters and sensors to a performance digital twin of the building, and gives the facilities management team a single pane view of operational performance metrics via the cloud.

It allows energy and carbon management of the building, and live tracking and verification of savings made from a recent HVAC refurbishment.

To set up IES Live, a calibrated energy model created in an earlier phase of the project using historic monthly measured data was upgraded into a digital twin using live hourly BMS and metered data from the building post refurbishment.

In this earlier phase, the IES Virtual Environment (IESVE) was used to create an initial energy model representing energy flow across spaces and rooms within the building. The model was then calibrated against monthly measured data for 2019 (pre-covid) to create a performance digital twin, allowing the prediction of the baseline energy use and testing of refurbishment options. After testing a number of refurbishment options on the model, the digital twin predicted 14% estimated energy savings from the chosen HVAC refurbishment.

Once this phase was complete and the building was reopened after refurbishment, the university appointed IES to upgrade the performance digital twin to make it more accurate by including operational insights gathered from the newly reopened building. This was done by connecting live data from the BMS and energy meters to the digital twin, which enabled the model to be re-calibrated to match current measured data on an hourly basis.

This upgraded digital twin was also used to look at further potential interventions to improve the operational performance of the building and move towards decarbonisation, helping create a long-term roadmap view and plan of decarbonisation interventions.

The university’s facilities management team is also using this operational performance digital twin, accessed via IES Live, to monitor and improve the building continually. Benchmarking against the simulated baseline, the university can track performance and gain improvement insights for energy, carbon and comfort. Additionally, the ongoing impact of the refurbishment is being measured and verified.

Using the IES Live implemented projects tracking page, it was possible to assess and verify in real time the impact of the HVAC refurbishment: between April and December 2023, it has led to a 23% reduction in energy consumption and £25,000 savings in operational cost. The difference from the predicted savings in the first phase can be ascribed to the improved accuracy of the latest model used to evaluate the actual savings.

IES Live (www.iesve.com/ies-live) is also helping prevent operational drift on the building, whereby the performance of building systems degrades over time, as any issues will be flagged and can be fixed before they begin to have an impact.

The university plans to continue collaborating with IES to create digital twins for three more buildings in the next phase.

“Improving the operation of buildings is key to mitigating energy and climate risk, cutting costs and emissions, meeting sustainability objectives and increasing resilience, not to mention being a vital part of a successful net zero strategy,” said Valeria Ferrando, associate director at IES. “However, you can’t improve what you can’t measure and there was a gap in the market for a tool that can connect live operational data, providing continuous insights and giving energy management teams a holistic view of how their building is performing. IES Live is a real game-changer, maximising the impact of a digital twin, which leverages a world-class simulation engine, and placing this power in the hands of those who need it.”

Tony Small, head of engineering services at the University of Liverpool (www.liverpool.ac.uk), added: “Working with IES on this project has given us detailed insight into the impact of our refurbishment work and will enable us to continually monitor and update our operational systems to ensure the building is operating efficiently. With building use, occupants and settings altering frequently, having access to this level of data means we can make informed decisions on improvements and ensure optimum performance doesn’t come at the expense of occupant comfort.”