LonWorks keeps control
Southroyd Primary School in Pudsey, West Yorkshire is delighted with its new heating control and automation system, which keeps staff and pupils comfortable while using as little energy as possible. Installed by Combserve Ltd, it uses a LonWorks open system to connect everything – sensors, controllers and an operator interface running on a desktop PC. The LonWorks standard provides flexibility to install the best system components from any manufacturer of LonMark-compatible products, at the outset, during upgrades and if existing components fail.
A PC-based CentraLine user interface enables the school’s Building Manager, Mick Laycock, to monitor the entire LonWorks system and make changes if necessary, all from his desk. “I can set schedules of heating times and temperature setpoints in each part of the school,” he said. “We have four controlled heating zones: the office areas, the Nursery, Key Stage One and Key Stage Two. Each has its own temperature sensor and time/temperature schedule.”
Combserve is contractor for all the school’s heating systems and Mick Laycock rates them very highly. When the school had problems with their outdated controls, Combserve proposed replacing it with a LonWorks system. The system installed uses two CentraLine programmable controllers, while the user software is also from CentraLine, but the open nature of the LonWorks system will allow upgrades and replacements to come from any manufacturer of LonWorks-compatible products.
The user interface presently runs on a dedicated PC, but Mick Laycock notes it is capable of being networked for access by other workstations in the school and even from his laptop at home – but these are just ideas for the future. “It is also capable of controlling the school’s lighting,” he observed. “We might go along that route one day.”
One controller controls three of the four heating zones, while the other controls the fourth zone, the boilers and a constant temperature circuit for fan convector units in the school hall: these units are operated manually as required, by switches and thermostats.
The school has three boilers connected in parallel which are fired as necessary by one of the two controllers, which also sequences their duties to equalise wear and tear.