These works have saved 300kW of our daily electrical peak and this has meant we have been able to build an extra building, without having to upgrade the campus electrical supply.
Richard Bettle , Energy and Utilities ManagerWe identified buildings where we could deliver significant savings through the energy efficient refurbishment of 20 packaged air handling units and replacement of 44 condenser fans on three of the chillers serving the main cooling network.
It was also determined that the University’s cooling infrastructure could yield large savings by upgrading the condenser fans on packaged chillers to more modern technology and we identified 3 units which could be upgraded. These savings are generated from both the newer fan motor designs and fan blade technology which has improved significantly since the original units were installed. In addition, a controller is installed in each refrigeration circuit to improve discharge pressure control and modulate the fan speed to ensure optimum comfort levels are maintained.
Works to the chiller and air handling systems will deliver a saving in excess of £60,000 per annum and have a payback period of under 5 years.
Our designers identified that upgrading the inefficient lighting system, with more efficient LED alternatives could generate large carbon savings and energy cost reductions. Our approach was to maximise savings based on a full re-design of lighting within the library to maximise energy savings whilst achieving compliance with industry standards. Overall, we installed 1,834 fittings, including emergency lighting such as exit signs and gateways and these replaced 2,759 older fittings. In appropriate areas, smart fittings were installed to control light levels based on the availability of natural daylight.
Prior to the works, we carried out lighting design calculations to ensure best practice standards were met and appropriate lighting levels would be achieved following the re-design. Once the works were completed, our engineers undertook a post installation “lux level survey” which ensured that all parts of the library enjoyed optimal lighting levels.
The upgrades to the lighting system deliver annual electricity savings of 587,000 kWh, which equates to 147 tonnes of CO2 and financial savings of over £72,000 per annum and will result in a payback period of just 7.6 years.
Our vCOMS (Vital Controls Optimisation & Management System) system was installed onto the Trend BMS and used to identify opportunities for improvement and, after implementation, to monitor the scheme and ensure optimum performance.
An example of the value vCOMS can bring to a scheme can be seen in one of the opportunities identified. It was noted that high internal temperatures inside and outside of occupancy were affecting comfort levels and increasing cooling demands in critical labs in the Chemistry, Biology and Sciences buildings. We introduced a heating economy control to account for internal and external temperatures and adjust the system to maintain a 20°C comfort set point and night setback, which reduced the temperature in the labs outside of occupancy hours. Despite higher ambient conditions post-delivery, the average space temperatures were reduced by almost 2°C across Chemistry North. In short, vCOMS identified an opportunity to improve comfort conditions while reducing energy consumption.
Once the energy conservation measures had been identified and installed vCOMS continues to ensure that the main energy consuming plant only operates at the times and temperatures which match the occupancy requirement. The system can do this by monitoring the performance of the building to ensure it operates within the expected parameters to maintain comfort levels for the building users. If the system performs outside of the expected parameters, improvements can be identified and implemented, which creates a cycle of continuous improvement.
One other essential feature of our vCOMS system is that it accurately measures and monitors savings. This is vital on a contract which has an energy performance contract as the client needs robust, audited data to ensure the KPIs have been achieved. The vCOMS system ensures we have the accurate data to issue reports and monitor actual performance against the expected design performance.
Overall, the energy conservation measures will save a guaranteed £184,000 per year, achieving project payback in under 6 years and then generating profit savings into the future. The biggest driver for the University, however, was to lower CO2 emissions; the first phase of works will reduce carbon emissions by 543 tonnes per year which equates to a 6.3% reduction across the buildings included in the scheme. In addition to energy savings, these works have saved 300kW of our daily electrical peak and this has meant we have been able to build an extra building, without having to upgrade the campus electrical supply.