Central St Giles, London

One of London’s most vibrant mixed-used developments has retrofitted Keraflo’s advanced electronic tank management system, Tanktronic, to help it take more precise control of its cold water storage and usage.

Central Saint Giles in the West End was completed in May 2010 and is home to some of the world’s leading media companies.

The prestigious destination consists of two buildings up to 15-storeys high that include 408,000 sq ft of office space, 109 residential apartments, restaurants, cafes, ‘green’ roof terraces and a public piazza.

Its substantial water use and cooling needs are managed through four huge water storage tanks, each holding between 65,000 and 75,000 litres.

While the development has achieved some outstanding sustainability awards, its water system was prone to occasional flooding in the basement where the storage tanks are held.

Retrofitting Keraflo’s Tanktronic has not only resolved the flooding issue, it is also enabling the M & E services provider to maximise the system’s operational effectiveness while furthering the sustainability goals of property owner Legal & General Investment Management.

Tanktronic comprises a simple-to-set-up Control Unit, which can control and monitor water and temperature levels in up to four individual tanks, a connection box and a sensor assembly that is suspended at full depth inside the storage tank.

Able to send alarms to a Building Management System, each Tanktronic Control Unit can manage up to four individual tank sensors, eight motorised Tanktronic Servo Ceramic Valves and two electro-mechanical Tanktronic Control Valves, plus additional third-party devices. An expansion S-Module enables further Control Valves to be added, if required. A Battery Module can also be specified to provide back-up power to the electrical mains supply.

Each water storage tank can be set with its own operating levels to follow up to 10 schedules, including valve close level, fill delay, alarm high / low and temperature high / low.

Intelligent features include a “holiday mode” schedule to match fluctuating demand and a two-stage alert for high and low water levels and temperature, with a second stage override that takes evasive action if the first-stage alert is not responded to.

Sustainability continues to be a key driver at Central Saint Giles, where 60% of rainwater falling on offices roofs and in the piazza is collected, treated and recycled, while 100% of water discharged from its cooling tower is collected for re-use.

Jeff Lengthorn, Property / Engineering Manager at Central Saint Giles, said because of the more effective control they are able to maintain the water at a lower level in the tanks, which could not be achieved under the float system.

There was also a payback on the investment in less than three years.

Jeff concluded: “Tanktronic helps us achieve two prime objectives; 1) the system is more efficient, and 2) it makes a key contribution to our sustainability goals. We are more much eco-friendly.”