With water companies continuing to reduce the mains pressure to help hit leakage targets, the requirement particularly from local authorities and housing associations for pressure boosting equipment to ensure there's water coming out of the taps on the top floors of tower blocks continues to grow. Unboosted water struggles to get above the third floor in most parts of the country.
A company that has specialised in the provision of these systems is Letchworth-based Complete Building Services (CBS). Director Peter Bradbury says that several of their clients have been looking to install pressure boosting equipment and the key to the success of these projects - apart from reliable pressure boosting sets - is easy installation and as little disruption to the lives of tenants as possible during the installation process. They've hit on a solution to all these requirements through their partnership with leading pump manufacturer Wilo.
This is perfectly illustrated by recent work undertaken by the company for clients Enfield Homes, the social housing arms-length management organisation (ALMO) for Enfield Council. Four tower blocks in Enfield, just inside the M25
in north London needed pressure boosting equipment to get the mains water reliably up to the top of the 13 story buildings.
The existing equipment - based in the basement of Brittany House was not up to the job and its reliability had begun to be called into question. CBS was asked to provide a solution that would provide reliability, cost effectiveness and the minimum of disruption to the tenants in the nearly 400 apartments affected.
Enter Wilo UK with its comprehensive range of pressure boosting sets. They recommended their Wilo Comfort -
Vario COR-2 Helix VE speed controlled pressure booster set, supplied with a CAVSA anti surge valve to address the potential issue of hydraulic shock in the mains water system. Controlling the flow of water into the system can prove difficult, as you don't want to affect the flow rate under normal working conditions. Wilo multi-pump sets are fitted with a CFS (controlled fill system) which limits the starting sequence after a forced shut down reducing the rate at which the system is refilled.
Preventing a vacuum can be achieved by fitting CAVSA valves (combined air vent & surge arrestor) at the top of each riser which will act as a vacuum break by allowing air to enter the system. These valves will also control the release of the air from the system when it starts to refill, therefore slowing down the rate at which the water enters the system.
The pump set selected for this project combines three pumps and the three-pump approach sees one operating, one able to assist if the call on water exceeds the capacity of that first pump, whilst a third 'sleeps'. All three pumps operate on a cycle, ensuring even wear across each of the pumps, with the added benefit that there is no stagnation of water addressing any legionella bacteria issues in the system.
The water was off to the nearly 400 dwellings for less than two hours whilst the old system was decommissioned and removed and the new one installed and powered up. They had no complaints from tenants at all having warned them the work was being done and that they would have to survive without mains water for a short while.
Full details of the Wilo pumps used in this installation and the other pumps in the range can be found at www.wilo.co.uk. More information on Complete Building Services can be found at www.completebuildingherts.com and more information about Enfield Homes can be found at www.enfield.gov.uk/Enfieldhomes.
