T&A overcomes control problems for Terminal 5 at Heathrow Airport

Tour & Andersson has supplied 1841 valves, including over a thousand differential-pressure and flow-control combination valves for the Terminal 5 buildings and rail station at Heathrow Airport. The company has also supplied three TA-Aqua+ oxidation technology units for the project. Specified by consulting engineers at Arup and installed by Babcock Engineering, the T&A equipment help optimise energy usage. The valves are part of a system that draws water from a district cooling scheme served by a central chiller farm. The only chilled-water pumps are in the chiller farm, not in the buildings. As a result of this system design, there was a risk of intermittent pressure throughout buildings on the site, which could lead to an uncomfortable indoor climate and undesirable noise — posing a challenge for 2-port control valves and the balancing of systems. An alternative solution was provided by T&A KTM and DKH combination valves, which provide greater flexibility, control and cost savings for variable-flow systems. The TA-Aqua+ systems is a chemical-free method of preventing legionella bacteria by helping remove all micro-organisms from hot and cold systems. All the pressure-independent control valves were recalibrated to design flows before delivery to site as required for the tightly timed installation programme.

Related links:

• www.tourandersson.co.uk