Staying warm for less – BMS improvements

During Spring 2021, several energy saving improvements to the Building Management System (BMS) were installed. The upgrades are part of the Public Sector Decarbonisation Scheme (PSDS) delivered by Salix and funded by the Department for Energy Security and Net Zero. We received a grant from Salix in 2020 for sustainable fixtures such as the BMS improvements, where for this project £84,108 of the total grant was used. The central BMS improvements included updates to various Heating Ventilation and Air Conditioning (HVAC) systems, which in turn digitalised our heating system making them easier to track and run automatically. As a result, the university has made a significant heat energy saving since.

Hopkins heating sensors

60 supply air temperature sensors were installed to replace the old units within the Hopkins building, that allowed timely fault identification. For example, because the new sensors are connected digitally to the BMS, we are now able to computer track unfavourable changes in energy consumption. The new automatic system is beneficial this way, since faults can be fixed quickly to save energy. This is exactly what happened when the heating system was able to correct a low lab room temperature of 16 degrees, which was corrected back up to 19 degrees within 10 minutes. However, some buildings are still not connected to the central BMS system or our meter reading platform, and consequently we do still have manual controls and some meters which are visited and recorded manually. The meter reads are then uploaded into our digital energy monitoring database, ‘Systems Link’.

The graph below demonstrates the energy saving made. The red line indicates what the kWh usage would have been if the BMS improvements were not made (modelled with external temperature data via Degree Day analysis).

Graph: Summary of the energy savings predicted compared with the post application measured data.

Our local weather station on the Whiteknights Campus records external air temperature locally, and this is modelled against heating data for previous years to reflect the expected daily use (based on the 2019/20 relationship between degree days and actual energy consumption). The actual 2020/21 daily use data after the BMS improvements were made were compared to the predicted (expected) use values. To summarise, the outcome of the improvements of the Energy Conservation Measure (ECM) yielded a saving of 38.90% which is 548% greater than the predicted 6%. Overall, we made some fantastic energy, cost and carbon savings than initially anticipated, as well as operational and comfort improvements for occupants, with less than half of the predicted payback time as well.

Table below: The actual savings calculated compared to the pre- project estimations.