The objective was to significantly reduce the carbon footprint across the portfolio of 9 buildings nationally which had a total pre-project consumption of 27.7GWh by focusing on minimising HVAC consumption to meet the SBTi targets that both DLG and Ascot Services have signed up to while ensuring occupants’ comfort was not compromised in any way.
This was especially difficult as all the buildings across the portfolio have varying occupancy times on individual floors and zones. This also meant that several bespoke solutions needed to be configured to work in unison, marrying intuitive engineering with clever processes while reimagining service delivery to achieve the desired results for the client, allowing us to effectively optimise the existing systems with constant monitoring and analysis to drive immediate change with minimal investment.
The Solution
The control strategy comprised of a combination of free heating and cooling, demand control, weather compensated system loading and bespoke/tailored optimiser control working in unison. The design was set up to automatically switch between varying combinations of these control elements to determine the most efficient way to run the HVAC plant while maintaining optimal environmental conditions.
Exercise strategy was also implemented to monitor run times and conduct plant exercising only when systems have not run for predetermined intervals, effectively maintaining plant availability and water quality.
The Benefits
The system ensures that the free heating and or cooling from the outside air is first utilised to condition the space, minimising the use of the boilers and chillers and their associated primary and secondary plant. The demand control ensures that the loading of these primary systems are available when required by specific zones within the buildings, even when occupancy patterns deviate from normal.
Having the system accessible from a “single pane of glass” with remote access capabilities meant that we were also able to respond to changes in environmental conditions in real-time, enabling persistent monitoring and testing while allowing for adjustments and changes to the strategy to be made quickly and effectively. We also developed automated analytical alarms to aid in the process of pinpointing shortfalls in the strategy, ensuring amendments were effectively deployed.
All of these combined resulted in a reduced consumption profile across all buildings in the portfolio and contributes to a prolonged plant lifecycle. It means that environmental conditions within the occupied spaces are always maintained at an optimal level at all times, ensuring the client’s objectives were achieved.
The Results
Compared to the pre-project annual consumption of 27.7GWh (2018) we saw a 22% reduction in consumption in 2019, a 55% reduction in consumption in 2020 (covid), a 55% reduction in consumption in 2021 was maintained even though occupancy went back up post-covid and a 72% reduction in consumption in 2022 (project completion).
“Ascot Services have provided a proactive approach to energy management across the DLG estate, working in partnership with the DLG Property team. The improvements that have been implemented have allowed the DLG Property Team to clearly monitor the building energy management systems across the core office portfolio whilst also allowing Ascot the opportunity to deliver further improvements as opportunities arise. Their vision has also allowed the introduction of the energy strategies which significantly reduced the energy usage across our office estate. The data gained from the BEMS management has supported DLG’s SBTI targets and requirements over the coming years.
With the installation of air quality sensors, we are now able to monitor and control the environmental conditions at any point in time across the buildings. This technology allows Ascot to implement BEMS strategies within the plant operational software to control the Air Handling Unit fan speeds based on CO2 and Temperature. Whilst this has positive energy and engineering impact it importantly has an incredibly positive impact on the office spaces and end users; providing an environment where DLG colleagues can excel.“
Tony Wilkinson
Head of Property Operations & Technical Services
Direct Line Group