Decarbonising heating at the University of Nottingham

Project summary

RSK businesses come together to create low-carbon energy solutions for the University of Nottingham’s law and social sciences buildings and Hallward Library.

The below metrics are the annual carbon equivalent saved by introducing the proposed measures:

The background

The Silcock Leedham Group, comprising Silcock Leedham Consulting Engineers and zed., worked with the University of Nottingham to decarbonise part of its heating system. Supporting the university to realise aspects of its carbon-management plan, Silcock Leedham Group provided mechanical, electrical and plumbing (MEP) design, building physics and energy modelling services to design and test a ground source heat pump solution. RSK Group sister company Carbon Zero Consulting also worked on the project and designed the boreholes for the proposed ground source heat pumps.

The university campus is served by a gas-fired district heating network (DHN) that has reached the end of its serviceable life. As part of the university’s carbon-management plan, the law and social sciences and Hallward Library buildings will be removed from the DHN and provided with decarbonised heat sources.

The challenges

The project involved several stakeholders with differing aims. To manage this, a project management group was established to focus on coordinating the project work across a range of objectives. It involved hosting university-based meetings and implementing a flexible approach to the design development and solutions. The previous proposals for the decarbonised heat sources included air or ground source heat pumps, which use heat obtained from the air or through an underground pipe. The university was located over one of the most usable aquifers in England, therefore the viability of using extraction and injection boreholes to use groundwater as the heat medium was tested. To offset the additional capital expenditure and to enhance the available project budget for the boreholes, the university was supported in applying for Salix grant funding.

The solutions

A full energy audit of the two buildings was carried out and included creating detailed virtual energy models. The models were used to test a variety of fabric-first upgrades and decarbonisation options, which later informed the solution that reached RIBA Stage 3: development design phase. Following the energy modelling outcomes, technical design was produced through RIBA stages 2 (concept design) and 3 (developed design), producing drawings with fully detailed plant and equipment procurement schedules. This included an electrical upgrade to deliver the power for the heat-pump-derived heating energy. During Stage 1 (preparation and brief), the brief was developed and proposals were outlined to take forward to develop the concept design.

The impacts

The output of the detailed energy modelling was used for a Salix grant application, enabling the university to offset costs and deliver a reduced-carbon outcome. Detailed thermal modelling evaluated several decarbonisation options after the fabric improvements had been agreed. This included the feasibility and appraisal of an open-loop ground source heat pump that has since been implemented into the RIBA Stage 3 design. In conjunction with Carbon Zero Consulting, desktop geological feasibility studies were undertaken, Environment Agency permit applications submitted, water features surveyed and boreholes designed.