Problems with controls and building-management systems often come to light when other plant, such as boilers, is replaced.
Tony Farrant explains, ‘The council works closely with schools as part of the premises development planning process. When surveys indicate a need for plant replacement, we recommend cost-efficient solutions. The fact that early building-management systems are now often in need of replacement shows just how fast time and technology are moving.
‘When changing control systems, we advise schools to opt for a future-proof solution that’s easy for non-technical staff to operate and preferably one where the software does not cost more than the hardware!’
An example of a project is Midhurst Grammar School, where controls in the boiler house serving around two-thirds of the classroom space had become obsolete.
Following recommendations by the property-services team, a new control system based on Coster’s DTE 611 was developed by Coster and SK Services.
A single DTE 611 unit and two slave units are built into the control panel in the boiler house. There are two gas-fired boilers, a gas-fired hot-water generator and pumps for both duty and standby boiler circulation. There are also pumps and modulating valves for five variable-temperature heating zones.
Boiler start-up time is optimised according to data acquired during the previous operating cycle.
A 2-wire system (Coster calls it a C-ring) provides communication between primary and slave controllers and information. It also enables information from devices such as temperature sensors to be shared by several controllers.
A feature of the Coster control concept is free-issue software, which is regularly updated and supplied free to customers with installations.
The system at Midhurst school provides web-browser capability, so the school bursar Peter Moorcroft has full control of the system from the PC on his desk. He can also acquire date to allow him to monitor trends on a daily, weekly and seasonal basis.
The same web-browser capability also makes possible full communication with the outside world.
Midhurst Grammar School is one of many in West Sussex exploiting the Coster approach to control architecture, and at least five others are planned.
