In 2010 At-Bristol signed up to the 10:10 campaign, with a commitment to cut carbon by 10% in a year. Taking a closer look they realised that there were some better ways to adjust the logic that controls the progressive energy saving features that the architects (Wilkinson Eyre), had incorporated into the building (during its development in 1999). There was potential to save a lot of energy with just a change in behaviour, and fine tuning of the existing systems, needed, to make more efficient use of existing systems. The approach to this was twofold, one set of measures related to ‘normal use’ of the building with best lighting and motion sensors put in place, and the other related to ‘abnormal use’ e.g. for events, only lighting/heating/cooling that particular part of the building.
Key to the temperature control in the building are eight large air source heat pumps that run on night electricity to heat or cool a Eutectic tank. The tank is designed to act as an environmentally-friendly buffer to keep temperatures even within the building, by releasing the hot or cold stored in the tank through 100 small air source heat pumps located throughout the building. This is then transported around the building, to where it is needed by a network of water pipes. In addition, in summer months, night air is passed through the building to cool the large mass of the concrete so that the next day the building itself absorbs heat to keep rooms cool. (The energy management systems in the building now also feature as part of At-Bristol’s educational programmes).
Also key to cutting energy use, was monitoring of the building, using an advanced system of 138 sensors that are able to report on energy use, every 30 minutes, throughout the building. The graphs produced by the monitoring proved to be particularly useful in identifying pinch points and opportunities to make reductions.
Another crucial measure in cutting carbon (in addition to educating and motivating the whole workforce) was setting up a specific energy reduction group which included key members of staff, from departments who actually had the capacity to change energy use (e.g. Facilities, Exhibitions, IT, Maintenance, Events and Security). The group meets regularly, the monitoring graphs allow the group to identify any anomalies and opportunities for reduction, specific tasks are allocated to individuals, and they report back on progress at the next meeting.
Having achieved a lot with the existing systems, their next project is looking at generating their own power, with a plan to have a photovoltaic installation on the At-Bristol roof by March next year.
More details on our other Carbon Champions here.