ELITE CONTRACT TEAM BUILDS NEW LONDON LANDMARK

The main part of the building, with its unique elliptical shape, has many advanced HVAC facilities. A central service core houses lifts and ventilation risers from the basement plant rooms. Hargreaves have provided distribution ductwork and floor grilles for a pressurised displacement system within the office areas of the building.

The use of the pressurised floor cavity technique has reduced the complexity of arterial ductwork. Ventilation rates vary directly with occupancy and usage. Fresh air supply rates of 12 to 16 litres/second per person are typical. Over and above ductwork supply, Hargreaves provided all prime movers such as AHU's and fans, together with silencers, constant volume boxes, grilles and diffusers.

Stale air is removed from occupied areas via ventilated luminaires in the false ceiling. During the winter, heat will be recovered from the exhaust air by a thermal wheel and used to temper incoming air. An innovative summer cooling system will also be used, based on naturally chilled water drawn from deep bore holes.

Fire engineering is a critical consideration. Senior Hargreaves, HFD series, fire resistant ductwork is used extensively for car park and kitchen extract. This ensures effective day-to-day ventilation with the assurance that under fire conditions products of combustion can be safely ported away. All HFD constructions are laboratory tested to certify their fire performance. Hatches provided on the kitchen extracts give access for cleaning to remove accumulations of grease and dust.

The project is under the control of construction managers Mace, who co-ordinate the trade contract team. Working to the specifications of Arup Consulting Engineers, Hargreaves developed the design as part of their contract works and were the lead co-ordinator for services in plant rooms and risers.

Drawings were submitted electronically to Arup for comment so that changes could be included before final approval ahead of ductwork manufacture. The complex process of overlaying drawings from different contractors enabled pressure points to be identified and eliminated. This streamlined the design process with further benefits on site to meet the rapid construction programme.

Uploaded: August 21, 2001

ADDITIONAL INFORMATION FOR EDITORS
The GLA headquarters is the landmark building on the More London development. Also under construction is the 500,000 square foot European headquarters building for global business advisers Ernst & Young. This new quarter for London completes the chain of regeneration and development along London's South Bank. The 13 acre site, immediately adjacent to Tower bridge and opposite the Tower of London, will provide 1.7 million square feet of offices, a hotel, shops, restaurants and is unified by high quality landscaped, pedestrianised, public open spaces in the Foster and Partners designed Masterplan.

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