CASE STUDY | CLATTERBRIDGE CANCER CENTRE hospital could open. In addition, the project completion and commissioning stages took place during the coronavirus pandemic. Nevertheless, the Clatterbridge Cancer Centre was completed on programme and on budget, and received its first patients in June 2020. As part of the handover process, Aecom implemented its bespoke soft landings procedure, EVOL+VE, to ensure the building was operating efficiently, reduce operational energy, and assist the facilities management (FM) operators to maintain a comfortable environment for patients and staff. All too often, the designers never CREATING A DIGITAL TWIN A digital model based on CIBSE TM54 was created to simulate energy use in operation. It includes plant efficiencies and operational profiles, along with details of the building fabric and everything we know about the building, says Taylor. Information included occupancy and regulated and unregulated energy use, which it combined with CIBSE weather data to understand how the building is expected to operate. The model and system performance were then validated during the buildings commissioning period, with the model updated to incorporate actual measured operating efficiencies. Mann says the digital twin which allows Aecom to look at the buildings energy consumption and predict the impact of tweaking set points. This can then be measured and discussed with the client before making final set point adjustments without affecting the actual building. To populate the digital twin, Aecom was granted read-only access to the hospitals building energy management system. This allowed the digital energy model to be updated with energy usage data to ensure alignment between it and the building. The process becomes more accurate with each iteration. Using the IES model, we could simulate plant operation and easily make changes to set points and time schedules, so we could assess their impact on energy consumption very quickly, says Taylor. By testing our proposed changes on the digital twin, we can make minor adjustments add up to a significant benefit to the client, in terms of a reduction in energy use, without compromising patient comfort. remain involved, so there is a huge performance gap between design data and reality, explains Mann. As part of the EVOL+VE process, and alongside the creation of the IES thermal comfort model, Aecom built a digital energy model, based on CIBSE TM54, which it then used to undertake operational energy simulations (see panel, Creating a digital twin). Energy and carbon-saving measures implemented so far include reducing the internal space temperature in the spaces with active chilled beams and reviewing operation of the site CHP plant. As the humidity levels in rooms with active chilled beams need close control to prevent condensation, lower internal temperatures can provide a greater energy-recovery benefit, and reduce the AHU reheat requirement, says Taylor. An assessment of the CHP plant operation and its ability to provide the project with a positive carbon benefit has also been undertaken. Were advising Clatterbridge how they can phase in and phase out the operation of the CHP to provide the greatest carbon benefit, which is when the grid operates using fossil-fuel power stations. According to Mann, Aecoms interventions have resulted in the building using 30% to 40% less thermal energy than NHS Benchmarks. Our continuing support to the Trust, through the Aecom EVOL+VE initiative will ensure we continue to reduce the buildings consumed energy. It is running so much better than the trust thought it would because of us working with the FM provider, he says. The buildings dynamic control systems also help the building perform more than 50% better than the Department of Healths current guideline carbon targets. So, it was no surprise that the scheme won Project of the Year Healthcare at this years CIBSE Building Performance Awards. The judges said: This project can be used by others as an exemplar of how buildings can be designed and then constantly tuned to ensure they continue to perform. Hear, hear. CJ A sectional view of the cancer centre 24 July 2022 www.cibsejournal.com CIBSE July 22 pp20-24 Clatterbridge Cancer hospital.indd 24 24/06/2022 15:15