SAV’s largest order for commissioning modules is for City development
The largest order yet placed for SAV’s FloCon’s commissioning modules is the Drapers Gardens 13-storey office and retail development currently under construction in the City of London. It is also one of the first to use modules with the recently introduced integral bypass.
Nearly 300 modules are being used, together with Alupex multi-layer flexible pipework, to distribute hot and cold water to over a thousand fan-coil units.
The completed building will offer 25 000 m2 of premium office space and 430 m2 for retail units. It is the first venture by Canary Wharf Developments outside London’s docklands.
Andrew Heath-Richardson, senior project manager for Canary Wharf Ltd, believes that the docklands’ experience has reaped a rich reward in design efficiency.
The air-conditioning system is based on fan coils served by boiler plant in the basement and packaged chillers on the roof. ‘The system was always going to use fan coils,’ says Andrew Heath-Richardson. ‘The question we explored was the best means of meeting CIBSE’s KS7 guide on variable-flow pipework systems.’
While variable-speed pumps can reduce energy consumption considerably, care is need if these savings are not swallowed by losses arising from poor control.
KS7 recommends that differential-pressure control valves (DPCVs) should be in straight branches feeding up to 12 terminal units, an arrangement that makes it easier to select 2-port control valves with good authority.
FlowCon commissioning modules with flexible pipework to the terminal units enable the system to be broken down into self-contained sub-systems, each served by a single distribution module with its own DPCV.
A costing exercise by the Canary Wharf team indicated that SAV’s modules offered a more cost efficient solution to KS7 than traditional in-series connections for hot and cold pipes to the FCUs.
Response to churn will be easier with local modules and flexible pipework than with long runs of rigid pipework and large dedicated pressure-control equipment on every floor.
The modules for Drapers Gardens include a bypass so that system flow never falls below 10% so as to protect the variable-speed pump.
Installation is being carried out by NG Bailey.