Teachers at Sutton Park Community Primary School in Kidderminster
are doing their best to ensure that their pupils do not take the
world’s natural resources for granted. They are being helped in
this quest by the site’s novel Trend building energy management
system (BEMS), part of whose function is to educate the children
about the importance of energy conservation and sustainable living.
In January 2010, Sutton Park Primary and its 240 pupils moved into brand new school buildings designed by Worcestershire County Council’s own Property Services team of architects and building services engineers. In contrast to the ageing premises they left behind, their current home is distinguished by low energy design and a strong emphasis on renewable resources, which include a wood-chip fuelled biomass boiler and a rainwater harvesting system. Good insulation and tight control and monitoring of the heating system by the Trend BEMS have helped ensure a high level of energy efficiency. In fact, heating costs are predicted to be less than half those of the old school, even though the new buildings have a larger floor area (2,000m² compared with, 624m²).
Sutton Park Community Primary is one of numerous Worcestershire County Council schools and buildings that are fitted with a Trend BEMS. All these systems are centrally managed from County Hall in Worcester, many of them via the council’s intranet. From
here, using Trend '963’ supervisors (graphical operator interfaces), the council’s engineers can adjust control settings and view system monitored data such as room temperatures and CO² concentrations within the schools, heating plant operation and, in some cases, utility meter readings. The pupils at Sutton Park can also look at BEMS collected data about their school - through custom-designed, child-friendly graphic pages that Trend created at the council’s request.
Uniquely, the interactive pages are displayed on whiteboards in the classrooms; they are accessed over the school’s IT network from an on-site ‘963’ server. This is done using a web browser that runs on a laptop connected to the whiteboard. Several classrooms can have access simultaneously, each being able to view whichever pages they wish.
Using simply worded text, animated graphics and a pictorial style familiar to a young audience, the children are shown how their classrooms are kept warm and their hand washing water is heated, and how rainwater is collected and used for flushing toilets.
The displays contain live and historic data collected by the BEMS, such as current temperature values and cumulative energy and mains/rain water consumption. Another page, which aims to encourage energy saving behaviour, gives the electricity usage or each classroom area - for the current day, the last month and the year to date. In the school’s library there is a Trend EnergyEYE, which provides a permanent display of the
latest energy consumption figures – and their CO² equivalents – on a large plasma screen.
The ‘963’ supervisor pages available to the council’s engineers are obviously much more detailed than those produced for the school. They give an in-depth picture of the operation and status of the heating system – including plant alarms – and provide data to aid the diagnosis of faults. They also enable changes to heating times and room and flow temperature setpoints.
The 100kW biomass boiler that serves the school’s radiator circuits is one of numerous similar units that Worcestershire County Council has installed in its premises to help meet its carbon reduction target in a cost-effective fashion. There is also a 130kW gas-fired boiler, though this is only enabled if the biomass plant is unable to achieve the required flow temperature unaided or if it cannot operate for some reason. Domestic hot water is supplied by a separate gas boiler.
One of the duties of the Trend BEMS is to maximise use of the biomass unit. This means it must allow for the boiler’s relatively long warm-up period. Thus, the BEMS not only computes the daily optimum start time for each heating circuit but also takes the earliest time calculated – and the outside air temperature – and works out how many hours in advance it must fire up the biomass plant. This ensures that the buffer tank it charges is up to temperature when needed.
To minimise unnecessary use of energy, the school is divided into three heating zones; each has a variable temperature heating circuit that is independently controlled by the BEMS. The classrooms are divided into two zones – north and south - while the main hall and admin area constitute the third. This means that the hall can be used outside school hours without having to bring the heating on in other areas.
The BEMS’s control and monitoring functions are carried out by a single Trend IQ controller. Two smaller IQs log readings from the various utility meters for downloading by the system supervisor. In addition to the main electricity and gas meters, there are nine electricity sub-meters, a gas meter on the DHW generator, a heat meter on the biomass boiler and mains water and rainwater meters.
Worcestershire County Council installed its first BEMS some 25 years ago and now has centrally managed systems in just over 250 of its sites, the vast majority of which are schools, though they also include offices, libraries and residential homes. Trend has supplied 101 of these systems, the first of them having been installed during the late nineteen nineties. There are also Trend intelligent controls in 44 village primary schools, which have energy bills of less than £2,000 per year each. Most are equipped with just a small stand - alone IQ controller and the sites are centrally monitored by the council on a reactive basis.
Though the child-friendly graphics used at Sutton Park are the first such screen displays that Trend has produced, the adaptability of the ‘963’ supervisor meant they were not difficult to create. Nor will it be hard to change them. Following feedback received from the school, it is now intended to modify and develop the displays with a view to establishing this innovative teaching aid as part of the curriculum.
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