MODERN building services technology is playing a key role in the redevelopment of the former headquarters building of Lloyds Bank in the heart of the City.
Preparing the great buildings of the past for a new role in the 21st Century is never an easy task. The old character of the structure must be retained, while a new internal environment is created - one more suited to the world of computers and 24-hour living.
Consultant Waterman Building Services faced a number of specific challenges in designing the mechanical services for the former Lloyds Bank HQ.
Opened in 1930 the Grade ll listed building stands on the block formed by Lombard Street and Cornhill, an area at the epicentre of London's banking history for more than 200 years.
The new owner IVG Asticus Real Estate, part of the IVG Immobilien AG Group, has developed an imaginative scheme for the site involving office space, restaurants and some 40,000ft2 of retail outlets.
All this will be achieved while retaining not only the facade but also the essential inner structure of the building. The key features beloved of English Heritage - including the great triple height banking hall, the magnificent Imperial staircase and even the original lifts - will all remain to be admired by a new generation.
The design involves a new inner core of offices hung on its own mega columns independent of the existing structure. Westock cellular beams will be used on these floors, with the perforations allowing easy access for services routing.
Below on floors one to three it is a very different story. Here the original concrete cased beams are retained. Installing a 2-pipe fan coil system with traditional rigid pipe interconnections potentially involved hundreds of penetrations through these beams - an expensive and laborious process.
Waterman's solution was to organise the air conditioning terminals into smaller semi-independent groups, with the operating valves for three to five fan coils located in a central module. All connections are made by multi-layer flexible pipework with an aluminium core. Pipework co-ordination becomes much easier and the number of beam penetrations required is kept to an absolute minimum.
Only chilled water connections were required. Heating will be by mean of electric heater batteries in the fan coils; the massive structure of the building ensures high levels of insulation, so this approach is well within the limits imposed under Part L.
The modular approach offers a number of other advantages as Stuart Bareham an associate director of Waterman Building Services explains: 'Centralising the valve arrangements by using Sav FloCon Commissioning Modules builds an inherent flexibility into the system - especially if one provides spare ports in the boxes for future fan coil additions. Buildings like these are almost invariably destined to be occupied by multiple tenants, each with individual space and environmental requirements. Meeting those changing needs is made much easier and the building's commercial viability is enhanced.'
The latest version of the Sav FloCon CM Module concept has all components including multi-port manifold, automatic air vent and isolation valves housed in a pre-insulated galvanised steel casing.
Insulating the casing means there's no need to attempt vapour sealing of individual components - seals that are virtually impossible to achieve and must be broken the first time access is required!
This box - no bigger than a standard fan coil unit - can be easily and quickly located in the ceiling or floor void. Connecting up the flexible multi-layer pipes is a matter of minutes and the FloCon Module is ready for action.
Other key system components including large, fine-mesh strainer, pressure gauges and specially designed commissioning valves can all be accommodated inside the box.
Easy access to all components is achieved via a hinged lid retained by two sturdy catches - and a retaining chain in the case of units intended for overhead mounting.
A single Sav FloCon CM Module can control the heating and cooling connections to up to six fan coils from one, easily accessible location.
Forward and back flushing can be easily achieved from the commissioning module for both the whole system and/or individual heating/cooling lines. Flow of LTHW and chilled water can be easily balanced by a single operative which is a cost-effective alternative to the teams of men with ladders and walkie-talkies that have been a feature of system commissioning until now.
The old laborious problem of trapped air is solved. Every Sav FloCon CM Module incorporates its own air bleed valve, which vents air as each line is filled under system pressure.
Balancing of the system flow rates is achieved by opening or closing the Double Regulating Valve - the body ring simultaneously raising or lowering the vertical indicator to give an easy- to-read setting. Unlike other valves of this type, the indicator scale can be read from any angle.
Once the desired flow rate has been established, the unit can be locked in position via an Allen key located beneath the flip-up cap at the top of the valve. The metal-to-metal thread enables the valve setting to be rigidly locked, so it can be closed and re-opened to its exact setting with great accuracy. The inside of the cap can even be given an identification mark so there is no need to tag the external parts of the valve.
The Cornhill development is at an early stage and has a long course to run before commissioning of the fan coil system begins. However, Stuart Bareham already has practical experience of Sav's FloCon Modules in another project.
'The benefits at the commissioning stage were remarkable. There were zero problems in a 125,000 ft2 building! Our commissioning engineers described the modules as 'a dream to work with' and all their figures were within the design set margins.
'It is a particular source of satisfaction to me that there's no need to re-lag the commissioning valves once commissioning has been completed, the box itself is pre-insulated. Just as well, because commissioning engineers never manage to get the insulation back on properly!'
Sav Modules T: 020 8941 4153