Sharing experiences
With a BMS installed in the Brunei Gallery of the University of London since 1995, Trend Controls asked Stephen McKinnell, head of energy management at the University of London since 2009 about his views on saving energy and how careful building-controls management has saved his organisation money.
Q Please give an indication to the scale of your site — number of buildings/staff on site/energy consumption etc.
The School of Oriental & African Studies (SOAS) at the University of London has over 5000 students from 133 countries, with around 50% of them being from overseas, and it specialises in the study of Asia, Africa and the near and middle east. The Brunei Gallery is part of the SOAS estate. It is a mixed-use building with has teaching, academic offices, conference facilities — including a 300-seat lecture theatre and galleries which have a permanent and loan exhibitions. So whilst it is a relatively small building at around 2500 m2 it is quite complicated in terms of services and operating requirements.
Q How long has the gallery been active in the monitoring and control of its energy?
The gallery has had a Trend BEMS in place since it was built in 1995 but was not fully in control of its energy consumption until I arrived in 2009. Whilst the building was the newest in the SOAS estate, it had the worst DEC rating at G. As it was a high-profile building in terms of external visitors it was a priority to improve this. Being a small institution, the estates team did not have the resource to manage energy fully — hence the creation of my shared role.
Q How did you identify what to work on first?
The starting point for reducing energy was to carry out an energy audit of the building to understand the existing plant and to look at the historic energy consumption. The consumption was compared against benchmarks for similar buildings, which revealed that it was performing poorly on both gas and electricity. The audit also revealed that the original chiller plant had reached the end of its life. Only one of the two chillers was working, as the other had been cannibalised to keep it running. The replacement of the chiller became the backbone for undertaking a full building-services improvement project.
Q How do you prioritise activities to reduce energy use?
Very early on I suspected the BMS had not been looked at for some considerable time, so I commissioned Trend to undertake an audit of the controls throughout the building. This reviewed the plant, the BMS hardware and the operating strategies. The existing chillers were also at the end of their economic life, and a new Turbocor chiller was specified to ensure efficient generation of chilled water for the galleries.
Q What has had the biggest return on investment?
The initial BMS audit itself had the fastest return on investment, as part of the process involves making changes on the day itself. The audit identified excessive operating hours, incorrect set points and minor faults that could be rectified to produce immediate savings. Implementing the actions within the main report such as the installation of the variable-speed drives on the air-handling plant, introducing night cooling and making the boilers and chiller plant demand led helped to halve gas consumption and reduce electricity consumption by 20%.
Q What do you think others should consider when they are just starting to look at saving energy?
A lot of people get hung up about sub-metering and being able to quantify energy savings. Whilst this helpful, it is not essential. If you don’t have sub-metering in place don’t put off projects because of this. Despite not having sub-metering at the time, we were still able to quantify savings from the overall reduction of energy use in the building.
Q What advice would you give someone who already has a BEMS in place but is looking for additional savings?
Don’t assume that just because you have a building and energy management system that it will be working well. Like all building services, they need maintenance and periodic reviews to get the best out of them.
A regular BEMS audit is probably the best money you could spend in producing quick and effective results. Also there are products out there for individual pieces of plant that may be marketed to you but you will probably find you can do something just as effective with your existing BEMS for less investment.
Q If you could give another gallery one piece of advice, what would it be?
The main reason the savings here have been so successful has been the collaboration between the estates team, the gallery curator and the Trend engineers.
Many curators are worried that by reducing energy consumption you may try and reduce the control conditions for the gallery areas, but in our case the upgraded controls have reduced energy and also improved the areas and the stability of conditions.
Q Regarding the control of energy, please summarise where you were before you embarked on the project, where you are now and any significant steps along the way.
Before we embarked on this project, we had a G-rated building on the Display Energy Certificate (DEC). It was using around 1.7 GWh of electricity and 1.2 GWh of gas. The latest DEC rating is now a C, which is a huge improvement. Electricity consumption is down around 500 000 kWh, down by over 70% and gas has dropped to 581 282 kWh, which is less than half of what it was before we embarked on this operation.
