Diversified technology and industrial company Johnson Controls Building Efficiency last month launched its latest version of the Central Plant Optimisation (CPO) system that can be used with any chiller, pump or tower brand to reduce plant energy consumption.
Johnson Controls Building Efficiency GM Neil Cameron says CPO can be used in new constructions as well as existing buildings, as long as they have an effective building auto- mation system (BMS), to reduce plant energy consumption by up to 60%.
The new automation system uses relational control algorithms to deliver plant energy savings ranging from 20% to 60%, a leap from the 15% delivered by standard scheduling algorithms used today, says Cameron.
In addition, the system can now be used to automate and optimise any plant with a BMS that uses industry standard protocols, such as BACnet and Modbus.
BACnet is a data communication protocol for building automation and control networks, and Modbus is a serial communications pro- tocol for connecting industrial electronic devices.
“Companies are more focused than ever on energy efficiency.
“More than 35% of the power required to run a building is consumed in one place – usually the central chilled water plant,” says Cameron.
He adds that the optimisation of central plant equipment represents a big opportunity for reducing life cycle costs, increased energy efficiency savings, reducing environmental impact, getting a faster payback on upgrade investments and ensuring consistent performance over time.
CPO helps to operate the central plant at its most efficient level. It uses algorithms to make real-time automatic adjustments to the system based on real-time building loads.
The CPO receives data about system performance and building loads from the BMS and uses algorithms to calculate the most energy efficient operating sequences for the entire heating, ventilating and air conditioning system.
It then feeds information back to BMS to adjust system operation. Automatic optimisation occurs every 30 seconds to ensure optimal speeds and achieve the highest operating efficiency possible.
Cameron says CPO works best with variable speed plant designs, where Web-based, real-time dashboards enable efficient measurement, verification and long-term management of plant performance.
He adds that an effective BMS provides equipment and component performance measurements, and that CPO enables building owners and operators to see essential plant components’ operating parameters, using smart algorithms to vary temperature and flow, and provide intelligent coordination between chiller power and plant auxiliary energy usage.
Moreover, the optimisation must be continuous and dynamic to maximise efficiency, notes Cameron. He mentions that CPO decisions are based on optimal power relationships among components, while control is based on relational control algorithms and calculations. This enables continuous automatic adjustment to meet real-time building loads.
CPO further provides 24/7 access to efficiency performance metrics, giving operators immediate visibility into inefficient system operation, but also providing the metrics that are critical to benchmarking and maintaining efficient operation continuously.