Wessex Water Operations Centre –- building services strategy

Citation

Heid, D. (2001), "Wessex Water Operations Centre –- building services strategy", Facilities, Vol. 19 No. 11/12. https://doi.org/10.1108/f.2001.06919kaf.001

Wessex Water Operations Centre –- building services strategy

Wessex Water Operations Centre –- building services strategyKeywords: Building industry, Environmental management, Ventilation systems

The new Wessex Water Operations Centre in Bath represents a culmination of client, design and construction team focused effort on creating a truly low energy, sustainable building.

Drawing on the combined experience of the design team, the brief was to provide a building which was contemporary in its approach to low energy usage, to satisfy the environmental aspirations of Wessex Water and be at the forefront of sustainable design. Those elements provided the design team with impetus for fresh thinking and a holistic approach to the finely-detailed exposed structure.

The building and systems design incorporates the principles of the BREEAM assessment method of objectively evaluating the environmental credentials of a building for which Wessex Water received the highest score of any assessment to date for its environmental stance. Wessex Water is also an M4I (Movement for Innovation) study project, which examines the way building, team relationships, working practices and sustainable issues are procured to reduce waste and improve efficiency.

Focusing on predominantly natural ventilation, the building utilises solar water heating panels, grey/rainwater collection and recycling, a Building Management System to monitor and control the building's environmental systems and artificial lighting control systems.

The environmental design was developed to minimise the use of mechanical air movement and cooling systems, while maintaining the indoor temperature at a maximum of 26^oC for the majority of the year. The internal space is dependent on the "Thermal Comfort" experienced by the occupants. This is a complex issue and no single environment will be judged satisfactory by all occupants, even if they are performing the same activity and wearing the same clothes. As a measure of the internal comfort conditioning, the design of the building considered the "Resultant Temperature" of the spaces and evaluation of the frequency of occurrence of high temperature events. An integral part of the environmental design in maintaining the internal comfort conditioning is the use of the exposed thermal mass of the concrete ceiling, utilising night ventilation of the building to cool this concrete for the next day's operation. The concrete mass can be considered as a sponge absorbing the rooms' heat gain during the day and then being drained of this heat at night by the cooler night air.

The way in which the spaces are automatically and manually controlled will play an important part in the success of the building. The systems allow for user interaction and at a level of input, which will be perceived by the users as being "in control". Actions are instant and the effect "visible".

The thermal performance of the building was modelled through the computer based simulation TAS software, to test the performance of the building as a naturally ventilated space and to quantify likely peak summertime temperatures in use. The nature of the modelling software also allowed comparative studies of issues such as shading and details of the building fabric, which have been used in the development and optimisation of the façade.

Daylighting analysis was undertaken to evaluate the potential of the design to provide appropriate levels of natural illumination. The artificial sky at Bath University School of Architecture was utilised, in conjunction with computer simulation, to carry out a number of daylight tests on building sections.

A key component of both the energy efficient design philosophy and internal aesthetic feel and look of the building is the design of the artificial lighting. The lighting system utilises the latest T5 lamp technology controlled via integral daylighting/presence sensing detection. The luminaires combine indirect and direct lighting to enhance the exposed sculpted concrete coffered ceiling, whilst meeting the overall design criteria of 350lux.

The predicted energy consumption figures are 100kWh/m²/annum (for normalised hours and excluding the energy requirements for the computer suites, control room and kitchen equipment). Heating energy is by far the largest element of the building energy usage and by using solar water heating panels, condensing boilers and zone control stations the means for meeting this tight energy criteria are there.

The Wessex Water Operations Centre has’commenced its life cycle and the team are currently involved in monitoring the building conditioning and adjusting the system controls to optimise performance.

BREEAM Assessment

BREEAM is the world's leading system for assessing the range of environmental impacts associated with buildings. Using BREEAM, the owner or developer of a building can evaluate and hence reduce any detrimental impact it may have on the environment, and demonstrate their commitment to this crucial issue at the same time.

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Buro Happold is a multi-disciplinary international practice of consulting engineers established in 1976, offering civil and structural engineering, mechanical and electrical engineering, quantity surveying, building services and environmental engineering, infrastructure and traffic engineering, geotechnical engineering, façade engineering, fire engineering, Computational Fluid Dynamics analysis, access consultancy, project management, urban design and a range of specialist CAD services.

Further information and illustrations available from: Helen Elias. Tel: 01225 320 627; Mobile: 0403 129 599; Fax: 01225 320 601; E-mail: helen.elias@burohappold.com

David HeidProject Manager, Buro Happold