Priva BMS to control sustainable heating/cooling technologies at college

When Chase High School in the Westcliff area of Southend launched its sixth form in 2008, the vision for its evolution was a new stand-alone ‘Post 16’ vocational building with a vibrant atmosphere in line with modern working environments. It was to be tastefully furnished, of modern design, adopting materials that create a light, clean impression and embrace sustainability.

Helping bring this vision to life, Colin Peacock Ltd, a Wickford-based company with over 60 years’ experience in controls and electrical engineering were nominated by the building designers NPS South East Ltd who are also overseeing the project, having first provided a detailed quotation and schematic design proposal.

“We have worked with NPS South East Ltd previously and they approached us to help on the control side,” says Nigel Thompson, managing director of Colin Peacock Ltd. “However, due to the complex nature of the project I pushed for the adoption of Priva BMS technology. The existing school building uses a system supplied by a Priva competitor but it has not been updated for over 10 years. We’ve completed a number of projects with Priva in the past three years and I had no doubt it was the best solution for the services incorporated into the Post 16 vocational building at Chase High.”

The stand-out feature of the facility’s specification was the use of several sustainable technologies such as Rainwater Harvesting, Solar Panels for Hot Water and TermoDeck, a system that uses cooler night air to cool the building.

The basic operating principle of TermoDeck uses the storage capacity/thermal mass of the hollow core slabs. Surplus heat, generated from body heat, lighting, computers and sun radiation is absorbed in the concrete slabs, increasing their temperature by 2-3°C during the day without affecting the comfort of occupants.

In the summer this excess heat is dissipated from the slabs by cooling them with night air in temperate climates, or using conventional chillers in hot climates, but with up to a 50% reduction in capacity when compared to conventional technologies. During winter, heat is stored in the slabs overnight to maintain comfortable internal conditions for the occupants the next day.

The use of the TermoDeck system in the UK has been steadily growing in recent years and Mr Thompson was confident that Priva was the BMS for the job.

“Using strategically placed sensors the BMS ensures the entire building is monitored and controlled,” he says. “While there are only a few radiators within stair wells and no conventional heaters, the control of the project is complicated slightly by the specification of trench heaters [natural convection] and duct heaters in certain areas/rooms. The Priva BMS helps ensure optimum temperatures are maintained in the most efficient manner.”

The BMS at Chase High’s new Post 16 vocational building is based on Priva’s Compri HX WebEngine, a solution for building management using the internet or local network that doesn’t require the use of a high capacity server.

The Priva Comprix HX WebEngine is complemented by two Compri HX 6E controllers (one in the boiler house and the other in the roof plant room). HX 6E is a customised building control system with a modern, completely programmable controller designed especially for small to medium-sized projects such as schools. Additionally there are 10 Priva HX4 outstation controllers strategically positioned around the building and approximately 250 Priva I/O points.

When fully installed and commissioned, the BMS will control all hot water, heating and ventilation/extraction requirements, as well as provide energy monitoring for electricity, gas and water. Additional considerations include the monitoring of harvested rainwater usage (used for lavatory flush), and the control of feature lighting both inside and outside (perimeter dusk to dawn) the building. It is also key (due to BREEAM requirements) that this information can be used for educational purposes and as such a good graphic interface is essential.

In terms of communications protocols, both Modbus (electricity meters, AHUs, heatpump, Duomo combined temperature and air quality sensors)and M-Bus (gas and water) are deployed. The Modbus electricity meters are connected through the Netbiter interface, and the AHU’s, heatpump and Duomo Sensors are directly controlled and monitored by the Priva HX Controllers.

Chase High’s Post 16 vocational building offers a range of vocational focused courses at Levels 1, 2 and 3 for around 300 students. Vocational areas, such as hairdressing and beauty salons, an art and design studio, science laboratories and a performing arts studio, are located on the ground floor along with the south facing atrium. This provides a mix of social and learning activity with informal learning areas. The first and second floors are flexible learning zones that can be adapted to meet the diverse challenges of the changing Post 16 provision. The building also includes a sports hall and a fitness centre, while natural light and openness are key features throughout.